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Diffstat (limited to 'gcc/gimplify.c')
| -rw-r--r-- | gcc/gimplify.c | 3754 |
1 files changed, 3754 insertions, 0 deletions
diff --git a/gcc/gimplify.c b/gcc/gimplify.c new file mode 100644 index 00000000000..dda218beab4 --- /dev/null +++ b/gcc/gimplify.c @@ -0,0 +1,3754 @@ +/* Tree lowering pass. This pass converts the GENERIC functions-as-trees + tree representation into the GIMPLE form. + + Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. + Major work done by Sebastian Pop <s.pop@laposte.net>, + Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA +02111-1307, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "rtl.h" +#include "errors.h" +#include "varray.h" +#include "tree-simple.h" +#include "tree-inline.h" +#include "diagnostic.h" +#include "langhooks.h" +#include "langhooks-def.h" +#include "tree-flow.h" +#include "timevar.h" +#include "except.h" +#include "hashtab.h" +#include "flags.h" +#include "real.h" +#include "function.h" +#include "output.h" +#include "expr.h" +#include "ggc.h" + +static struct gimplify_ctx +{ + tree current_bind_expr; + bool save_stack; + tree temps; + tree conditional_cleanups; + int conditions; + tree exit_label; + varray_type case_labels; + /* The formal temporary table. Should this be persistent? */ + htab_t temp_htab; +} *gimplify_ctxp; + + +/* Formal (expression) temporary table handling: Multiple occurrences of + the same scalar expression are evaluated into the same temporary. */ + +typedef struct gimple_temp_hash_elt +{ + tree val; /* Key */ + tree temp; /* Value */ +} elt_t; + +/* Return a hash value for a formal temporary table entry. */ + +static hashval_t +gimple_tree_hash (const void *p) +{ + tree t = ((const elt_t *)p)->val; + return iterative_hash_expr (t, 0); +} + +/* Compare two formal temporary table entries. */ + +static int +gimple_tree_eq (const void *p1, const void *p2) +{ + tree t1 = ((const elt_t *)p1)->val; + tree t2 = ((const elt_t *)p2)->val; + enum tree_code code = TREE_CODE (t1); + + if (TREE_CODE (t2) != code + || TREE_TYPE (t1) != TREE_TYPE (t2)) + return 0; + + if (!operand_equal_p (t1, t2, 0)) + return 0; + + /* Only allow them to compare equal if they also hash equal; otherwise + results are nondeterminate, and we fail bootstrap comparison. */ + if (gimple_tree_hash (p1) != gimple_tree_hash (p2)) + abort (); + + return 1; +} + +/* Set up a context for the gimplifier. */ + +void +push_gimplify_context (void) +{ + if (gimplify_ctxp) + abort (); + gimplify_ctxp + = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx)); + gimplify_ctxp->temp_htab + = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free); +} + +/* Tear down a context for the gimplifier. If BODY is non-null, then + put the temporaries into the outer BIND_EXPR. Otherwise, put them + in the unexpanded_var_list. */ + +void +pop_gimplify_context (tree body) +{ + if (!gimplify_ctxp || gimplify_ctxp->current_bind_expr) + abort (); + + if (body) + declare_tmp_vars (gimplify_ctxp->temps, body); + else + record_vars (gimplify_ctxp->temps); + +#if 0 + if (!quiet_flag) + fprintf (stderr, " collisions: %f ", + htab_collisions (gimplify_ctxp->temp_htab)); +#endif + + htab_delete (gimplify_ctxp->temp_htab); + free (gimplify_ctxp); + gimplify_ctxp = NULL; +} + +void +gimple_push_bind_expr (tree bind) +{ + TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr; + gimplify_ctxp->current_bind_expr = bind; +} + +void +gimple_pop_bind_expr (void) +{ + gimplify_ctxp->current_bind_expr + = TREE_CHAIN (gimplify_ctxp->current_bind_expr); +} + +tree +gimple_current_bind_expr (void) +{ + return gimplify_ctxp->current_bind_expr; +} + +/* Returns true iff there is a COND_EXPR between us and the innermost + CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */ + +static bool +gimple_conditional_context (void) +{ + return gimplify_ctxp->conditions > 0; +} + +/* Note that we've entered a COND_EXPR. */ + +static void +gimple_push_condition (void) +{ + ++(gimplify_ctxp->conditions); +} + +/* Note that we've left a COND_EXPR. If we're back at unconditional scope + now, add any conditional cleanups we've seen to the prequeue. */ + +static void +gimple_pop_condition (tree *pre_p) +{ + int conds = --(gimplify_ctxp->conditions); + if (conds == 0) + { + append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p); + gimplify_ctxp->conditional_cleanups = NULL_TREE; + } + else if (conds < 0) + abort (); +} + +/* A subroutine of append_to_statement_list{,_force}. */ + +static void +append_to_statement_list_1 (tree t, tree *list_p, bool side_effects) +{ + tree list = *list_p; + tree_stmt_iterator i; + + if (!list) + { + if (t && TREE_CODE (t) == STATEMENT_LIST) + { + *list_p = t; + return; + } + *list_p = list = alloc_stmt_list (); + } + + if (!side_effects) + return; + + i = tsi_last (list); + tsi_link_after (&i, t, TSI_CONTINUE_LINKING); +} + +/* Add T to the end of the list container pointed by LIST_P. + If T is an expression with no effects, it is ignored. */ + +void +append_to_statement_list (tree t, tree *list_p) +{ + append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false); +} + +/* Similar, but the statement is always added, regardless of side effects. */ + +void +append_to_statement_list_force (tree t, tree *list_p) +{ + append_to_statement_list_1 (t, list_p, t != NULL); +} + +/* Add T to the end of a COMPOUND_EXPR pointed by LIST_P. The type + of the result is the type of T. */ + +void +append_to_compound_expr (tree t, tree *list_p) +{ + if (!t) + return; + if (!*list_p) + *list_p = t; + else + *list_p = build (COMPOUND_EXPR, TREE_TYPE (t), *list_p, t); +} + +/* Strip off a legitimate source ending from the input string NAME of + length LEN. Rather than having to know the names used by all of + our front ends, we strip off an ending of a period followed by + up to five characters. (Java uses ".class".) */ + +static inline void +remove_suffix (char *name, int len) +{ + int i; + + for (i = 2; i < 8 && len > i; i++) + { + if (name[len - i] == '.') + { + name[len - i] = '\0'; + break; + } + } +} + +/* Create a nameless artificial label and put it in the current function + context. Returns the newly created label. */ + +tree +create_artificial_label (void) +{ + tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node); + DECL_ARTIFICIAL (lab) = 1; + DECL_CONTEXT (lab) = current_function_decl; + return lab; +} + +/* Create a new temporary name with PREFIX. Returns an indentifier. */ + +static GTY(()) unsigned int tmp_var_id_num; + +static tree +create_tmp_var_name (const char *prefix) +{ + char *tmp_name; + + if (prefix) + { + char *preftmp = ASTRDUP (prefix); + remove_suffix (preftmp, strlen (preftmp)); + prefix = preftmp; + } + + ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++); + return get_identifier (tmp_name); +} + + +/* Create a new temporary variable declaration of type TYPE. + Does NOT push it into the current binding. */ + +tree +create_tmp_var_raw (tree type, const char *prefix) +{ + tree tmp_var; + tree new_type; + + /* Make the type of the variable writable. */ + new_type = build_type_variant (type, 0, 0); + TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type); + + tmp_var = build_decl (VAR_DECL, create_tmp_var_name (prefix), type); + + /* The variable was declared by the compiler. */ + DECL_ARTIFICIAL (tmp_var) = 1; + /* And we don't want debug info for it. */ + DECL_IGNORED_P (tmp_var) = 1; + + /* Make the variable writable. */ + TREE_READONLY (tmp_var) = 0; + + DECL_EXTERNAL (tmp_var) = 0; + TREE_STATIC (tmp_var) = 0; + TREE_USED (tmp_var) = 1; + + return tmp_var; +} + +/* Create a new temporary variable declaration of type TYPE. DOES push the + variable into the current binding. Further, assume that this is called + only from gimplification or optimization, at which point the creation of + certain types are bugs. */ + +tree +create_tmp_var (tree type, const char *prefix) +{ + tree tmp_var; + +#if defined ENABLE_CHECKING + /* If the type is an array or a type which must be created by the + frontend, something is wrong. */ + if (TREE_CODE (type) == ARRAY_TYPE || TREE_ADDRESSABLE (type)) + abort (); + if (!COMPLETE_TYPE_P (type)) + abort (); + /* Variable sized types require lots of machinery to create; the + optimizers shouldn't be doing anything of the sort. */ + if (TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST) + abort (); +#endif + + tmp_var = create_tmp_var_raw (type, prefix); + gimple_add_tmp_var (tmp_var); + return tmp_var; +} + +/* Given a tree, try to return a useful variable name that we can use + to prefix a temporary that is being assigned the value of the tree. + I.E. given <temp> = &A, return A. */ + +const char * +get_name (tree t) +{ + tree stripped_decl; + + stripped_decl = t; + STRIP_NOPS (stripped_decl); + if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl)) + return IDENTIFIER_POINTER (DECL_NAME (stripped_decl)); + else + { + switch (TREE_CODE (stripped_decl)) + { + case ADDR_EXPR: + return get_name (TREE_OPERAND (stripped_decl, 0)); + break; + default: + return NULL; + } + } +} + +/* Create a temporary with a name derived from VAL. Subroutine of + lookup_tmp_var; nobody else should call this function. */ + +static inline tree +create_tmp_from_val (tree val) +{ + return create_tmp_var (TREE_TYPE (val), get_name (val)); +} + +/* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse + an existing expression temporary. */ + +static tree +lookup_tmp_var (tree val, bool is_formal) +{ + if (!is_formal || TREE_SIDE_EFFECTS (val)) + return create_tmp_from_val (val); + else + { + elt_t elt, *elt_p; + void **slot; + + elt.val = val; + slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT); + if (*slot == NULL) + { + elt_p = xmalloc (sizeof (*elt_p)); + elt_p->val = val; + elt_p->temp = create_tmp_from_val (val); + *slot = (void *)elt_p; + } + else + elt_p = (elt_t *) *slot; + + return elt_p->temp; + } +} + +/* Returns a formal temporary variable initialized with VAL. PRE_P is as + in gimplify_expr. Only use this function if: + + 1) The value of the unfactored expression represented by VAL will not + change between the initialization and use of the temporary, and + 2) The temporary will not be otherwise modified. + + For instance, #1 means that this is inappropriate for SAVE_EXPR temps, + and #2 means it is inappropriate for && temps. + + For other cases, use get_initialized_tmp_var instead. */ + +static tree +internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal) +{ + tree t, mod; + char class; + + gimplify_expr (&val, pre_p, post_p, is_gimple_rhs, fb_rvalue); + + t = lookup_tmp_var (val, is_formal); + + mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val); + + class = TREE_CODE_CLASS (TREE_CODE (val)); + if (EXPR_LOCUS (val)) + SET_EXPR_LOCUS (mod, EXPR_LOCUS (val)); + else + annotate_with_locus (mod, input_location); + /* gimplify_modify_expr might want to reduce this further. */ + gimplify_stmt (&mod); + append_to_statement_list (mod, pre_p); + + return t; +} + +tree +get_formal_tmp_var (tree val, tree *pre_p) +{ + return internal_get_tmp_var (val, pre_p, NULL, true); +} + +/* Returns a temporary variable initialized with VAL. PRE_P and POST_P + are as in gimplify_expr. */ + +tree +get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p) +{ + return internal_get_tmp_var (val, pre_p, post_p, false); +} + +/* Returns true if T is a GIMPLE temporary variable, false otherwise. */ + +bool +is_gimple_tmp_var (tree t) +{ + /* FIXME this could trigger for other local artificials, too. */ + return (TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t) + && !TREE_STATIC (t) && !DECL_EXTERNAL (t)); +} + +/* Declares all the variables in VARS in SCOPE. Returns the last + DECL_STMT emitted. */ + +void +declare_tmp_vars (tree vars, tree scope) +{ + tree last = vars; + if (last) + { + tree temps; + + /* C99 mode puts the default 'return 0;' for main() outside the outer + braces. So drill down until we find an actual scope. */ + while (TREE_CODE (scope) == COMPOUND_EXPR) + scope = TREE_OPERAND (scope, 0); + + if (TREE_CODE (scope) != BIND_EXPR) + abort (); + + temps = nreverse (last); + TREE_CHAIN (last) = BIND_EXPR_VARS (scope); + BIND_EXPR_VARS (scope) = temps; + + /* We don't add the temps to the block for this BIND_EXPR, as we're + not interested in debugging info for them. */ + } +} + +void +gimple_add_tmp_var (tree tmp) +{ + if (TREE_CHAIN (tmp) || tmp->decl.seen_in_bind_expr) + abort (); + + DECL_CONTEXT (tmp) = current_function_decl; + tmp->decl.seen_in_bind_expr = 1; + + if (gimplify_ctxp) + { + TREE_CHAIN (tmp) = gimplify_ctxp->temps; + gimplify_ctxp->temps = tmp; + } + else if (cfun) + record_vars (tmp); + else + declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl)); +} + +/* Determines whether to assign a locus to the statement STMT. */ + +static bool +should_carry_locus_p (tree stmt) +{ + /* Don't emit a line note for a label. We particularly don't want to + emit one for the break label, since it doesn't actually correspond + to the beginning of the loop/switch. */ + if (TREE_CODE (stmt) == LABEL_EXPR) + return false; + + /* Do not annotate empty statements, since it confuses gcov. */ + if (!TREE_SIDE_EFFECTS (stmt)) + return false; + + return true; +} + +void +annotate_all_with_locus (tree *stmt_p, location_t locus) +{ + tree_stmt_iterator i; + + if (!*stmt_p) + return; + + for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i)) + { + tree t = tsi_stmt (i); + +#ifdef ENABLE_CHECKING + /* Assuming we've already been gimplified, we shouldn't + see nested chaining constructs anymore. */ + if (TREE_CODE (t) == STATEMENT_LIST + || TREE_CODE (t) == COMPOUND_EXPR) + abort (); +#endif + + if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t))) + && ! EXPR_HAS_LOCATION (t) + && should_carry_locus_p (t)) + annotate_with_locus (t, locus); + } +} + +/* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes. + These nodes model computations that should only be done once. If we + were to unshare something like SAVE_EXPR(i++), the gimplification + process would create wrong code. */ + +static tree +mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data) +{ + enum tree_code code = TREE_CODE (*tp); + /* Don't unshare types, constants and SAVE_EXPR nodes. */ + if (TREE_CODE_CLASS (code) == 't' + || TREE_CODE_CLASS (code) == 'c' + || code == SAVE_EXPR || code == TARGET_EXPR + /* We can't do anything sensible with a BLOCK used as an expression, + but we also can't abort when we see it because of non-expression + uses. So just avert our eyes and cross our fingers. Silly Java. */ + || code == BLOCK) + *walk_subtrees = 0; + else if (code == BIND_EXPR) + abort (); + else + copy_tree_r (tp, walk_subtrees, data); + + return NULL_TREE; +} + +/* Mark all the _DECL nodes under *TP as volatile. FIXME: This must die + after VA_ARG_EXPRs are properly lowered. */ + +static tree +mark_decls_volatile_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + if (SSA_VAR_P (*tp)) + TREE_THIS_VOLATILE (*tp) = 1; + + return NULL_TREE; +} + + +/* Callback for walk_tree to unshare most of the shared trees rooted at + *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1), + then *TP is deep copied by calling copy_tree_r. + + This unshares the same trees as copy_tree_r with the exception of + SAVE_EXPR nodes. These nodes model computations that should only be + done once. If we were to unshare something like SAVE_EXPR(i++), the + gimplification process would create wrong code. */ + +static tree +copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + /* If this node has been visited already, unshare it and don't look + any deeper. */ + if (TREE_VISITED (*tp)) + { + walk_tree (tp, mostly_copy_tree_r, NULL, NULL); + *walk_subtrees = 0; + } + else + { + /* Otherwise, mark the tree as visited and keep looking. */ + TREE_VISITED (*tp) = 1; + if (TREE_CODE (*tp) == VA_ARG_EXPR) + { + /* Mark any _DECL inside the operand as volatile to avoid the + optimizers messing around with it. FIXME: Remove this once + VA_ARG_EXPRs are properly lowered. */ + walk_tree (&TREE_OPERAND (*tp, 0), mark_decls_volatile_r, + NULL, NULL); + } + } + return NULL_TREE; +} + +static tree +unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + if (TREE_VISITED (*tp)) + TREE_VISITED (*tp) = 0; + else + *walk_subtrees = 0; + + return NULL_TREE; +} + +/* Unshare T and all the trees reached from T via TREE_CHAIN. */ + +void +unshare_all_trees (tree t) +{ + walk_tree (&t, copy_if_shared_r, NULL, NULL); + walk_tree (&t, unmark_visited_r, NULL, NULL); +} + +/* Unconditionally make an unshared copy of EXPR. This is used when using + stored expressions which span multiple functions, such as BINFO_VTABLE, + as the normal unsharing process can't tell that they're shared. */ + +tree +unshare_expr (tree expr) +{ + walk_tree (&expr, mostly_copy_tree_r, NULL, NULL); + return expr; +} + +/* A terser interface for building a representation of a exception + specification. */ + +tree +gimple_build_eh_filter (tree body, tree allowed, tree failure) +{ + tree t; + + /* FIXME should the allowed types go in TREE_TYPE? */ + t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE); + append_to_statement_list (failure, &EH_FILTER_FAILURE (t)); + + t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t); + append_to_statement_list (body, &TREE_OPERAND (t, 0)); + + return t; +} + + +/* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both + contain statements and have a value. Assign its value to a temporary + and give it void_type_node. Returns the temporary, or NULL_TREE if + WRAPPER was already void. */ + +tree +voidify_wrapper_expr (tree wrapper) +{ + if (!VOID_TYPE_P (TREE_TYPE (wrapper))) + { + tree *p; + tree temp; + + /* Set p to point to the body of the wrapper. */ + switch (TREE_CODE (wrapper)) + { + case BIND_EXPR: + /* For a BIND_EXPR, the body is operand 1. */ + p = &BIND_EXPR_BODY (wrapper); + break; + + default: + p = &TREE_OPERAND (wrapper, 0); + break; + } + + /* Advance to the last statement. Set all container types to void. */ + if (TREE_CODE (*p) == STATEMENT_LIST) + { + tree_stmt_iterator i = tsi_last (*p); + p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i); + } + else + { + for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1)) + { + TREE_SIDE_EFFECTS (*p) = 1; + TREE_TYPE (*p) = void_type_node; + } + } + + if (p && TREE_CODE (*p) == INIT_EXPR) + { + /* The C++ frontend already did this for us. */; + temp = TREE_OPERAND (*p, 0); + } + else if (p && TREE_CODE (*p) == INDIRECT_REF) + { + /* If we're returning a dereference, move the dereference outside + the wrapper. */ + tree ptr = TREE_OPERAND (*p, 0); + temp = create_tmp_var (TREE_TYPE (ptr), "retval"); + *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr); + temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp); + /* If this is a BIND_EXPR for a const inline function, it might not + have TREE_SIDE_EFFECTS set. That is no longer accurate. */ + TREE_SIDE_EFFECTS (wrapper) = 1; + } + else + { + temp = create_tmp_var (TREE_TYPE (wrapper), "retval"); + if (p && !IS_EMPTY_STMT (*p)) + { + *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p); + TREE_SIDE_EFFECTS (wrapper) = 1; + } + } + + TREE_TYPE (wrapper) = void_type_node; + return temp; + } + + return NULL_TREE; +} + +/* Prepare calls to builtins to SAVE and RESTORE the stack as well as + temporary through that they comunicate. */ + +static void +build_stack_save_restore (tree *save, tree *restore) +{ + tree save_call, tmp_var; + + save_call = + build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE], + NULL_TREE); + tmp_var = create_tmp_var (ptr_type_node, "saved_stack"); + + *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call); + *restore = + build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE], + tree_cons (NULL_TREE, tmp_var, NULL_TREE)); +} + +/* Gimplify a BIND_EXPR. Just voidify and recurse. */ + +static enum gimplify_status +gimplify_bind_expr (tree *expr_p, tree *pre_p) +{ + tree bind_expr = *expr_p; + tree temp = voidify_wrapper_expr (bind_expr); + bool old_save_stack = gimplify_ctxp->save_stack; + tree t; + + /* Mark variables seen in this bind expr. */ + for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t)) + t->decl.seen_in_bind_expr = 1; + + gimple_push_bind_expr (bind_expr); + gimplify_ctxp->save_stack = false; + + gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr)); + + if (gimplify_ctxp->save_stack) + { + tree stack_save, stack_restore; + + /* Save stack on entry and restore it on exit. Add a try_finally + block to achieve this. Note that mudflap depends on the + format of the emitted code: see mx_register_decls(). */ + build_stack_save_restore (&stack_save, &stack_restore); + + t = build (TRY_FINALLY_EXPR, void_type_node, + BIND_EXPR_BODY (bind_expr), NULL_TREE); + append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1)); + + BIND_EXPR_BODY (bind_expr) = NULL_TREE; + append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr)); + append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr)); + } + + gimplify_ctxp->save_stack = old_save_stack; + gimple_pop_bind_expr (); + + if (temp) + { + *expr_p = temp; + append_to_statement_list (bind_expr, pre_p); + return GS_OK; + } + else + return GS_ALL_DONE; +} + +/* Gimplify a RETURN_EXPR. If the expression to be returned is not a + GIMPLE value, it is assigned to a new temporary and the statement is + re-written to return the temporary. + + PRE_P points to the list where side effects that must happen before + STMT should be stored. */ + +static enum gimplify_status +gimplify_return_expr (tree stmt, tree *pre_p) +{ + tree ret_expr = TREE_OPERAND (stmt, 0); + tree result; + + if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL) + return GS_ALL_DONE; + + if (ret_expr == error_mark_node) + return GS_ERROR; + + if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl)))) + result = NULL_TREE; + else + { + result = TREE_OPERAND (ret_expr, 0); +#ifdef ENABLE_CHECKING + if ((TREE_CODE (ret_expr) != MODIFY_EXPR + && TREE_CODE (ret_expr) != INIT_EXPR) + || TREE_CODE (result) != RESULT_DECL) + abort (); +#endif + } + + /* We need to pass the full MODIFY_EXPR down so that special handling + can replace it with something else. */ + gimplify_stmt (&ret_expr); + + if (result == NULL_TREE) + TREE_OPERAND (stmt, 0) = NULL_TREE; + else if (ret_expr == TREE_OPERAND (stmt, 0)) + /* It was already GIMPLE. */ + return GS_ALL_DONE; + else + { + /* If there's still a MODIFY_EXPR of the RESULT_DECL after + gimplification, find it so we can put it in the RETURN_EXPR. */ + tree ret = NULL_TREE; + + if (TREE_CODE (ret_expr) == STATEMENT_LIST) + { + tree_stmt_iterator si; + for (si = tsi_start (ret_expr); !tsi_end_p (si); tsi_next (&si)) + { + tree sub = tsi_stmt (si); + if (TREE_CODE (sub) == MODIFY_EXPR + && TREE_OPERAND (sub, 0) == result) + { + ret = sub; + if (tsi_one_before_end_p (si)) + tsi_delink (&si); + else + { + /* If there were posteffects after the MODIFY_EXPR, + we need a temporary. */ + tree tmp = create_tmp_var (TREE_TYPE (result), "retval"); + TREE_OPERAND (ret, 0) = tmp; + ret = build (MODIFY_EXPR, TREE_TYPE (result), + result, tmp); + } + break; + } + } + } + + if (ret) + TREE_OPERAND (stmt, 0) = ret; + else + /* The return value must be set up some other way. Just tell + expand_return that we're returning the RESULT_DECL. */ + TREE_OPERAND (stmt, 0) = result; + } + + append_to_statement_list (ret_expr, pre_p); + return GS_ALL_DONE; +} + +/* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body + and replacing the LOOP_EXPR with goto, but if the loop contains an + EXIT_EXPR, we need to append a label for it to jump to. */ + +static enum gimplify_status +gimplify_loop_expr (tree *expr_p, tree *pre_p) +{ + tree saved_label = gimplify_ctxp->exit_label; + tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE); + tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label)); + + append_to_statement_list (start_label, pre_p); + + gimplify_ctxp->exit_label = NULL_TREE; + + gimplify_stmt (&LOOP_EXPR_BODY (*expr_p)); + append_to_statement_list (LOOP_EXPR_BODY (*expr_p), pre_p); + + if (gimplify_ctxp->exit_label) + { + append_to_statement_list (jump_stmt, pre_p); + *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label); + } + else + *expr_p = jump_stmt; + + gimplify_ctxp->exit_label = saved_label; + + return GS_ALL_DONE; +} + +/* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can + branch to. */ + +static enum gimplify_status +gimplify_switch_expr (tree *expr_p, tree *pre_p) +{ + tree switch_expr = *expr_p; + enum gimplify_status ret; + + ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL, + is_gimple_val, fb_rvalue); + + if (SWITCH_BODY (switch_expr)) + { + varray_type labels, saved_labels; + bool saw_default; + tree label_vec, t; + size_t i, len; + + /* If someone can be bothered to fill in the labels, they can + be bothered to null out the body too. */ + if (SWITCH_LABELS (switch_expr)) + abort (); + + saved_labels = gimplify_ctxp->case_labels; + VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels"); + + gimplify_to_stmt_list (&SWITCH_BODY (switch_expr)); + + labels = gimplify_ctxp->case_labels; + gimplify_ctxp->case_labels = saved_labels; + + len = VARRAY_ACTIVE_SIZE (labels); + saw_default = false; + + for (i = 0; i < len; ++i) + { + t = VARRAY_TREE (labels, i); + if (!CASE_LOW (t)) + { + saw_default = true; + break; + } + } + + label_vec = make_tree_vec (len + !saw_default); + SWITCH_LABELS (*expr_p) = label_vec; + + for (i = 0; i < len; ++i) + TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i); + + append_to_statement_list (switch_expr, pre_p); + + /* If the switch has no default label, add one, so that we jump + around the switch body. */ + if (!saw_default) + { + t = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE, + NULL_TREE, create_artificial_label ()); + TREE_VEC_ELT (label_vec, len) = t; + append_to_statement_list (SWITCH_BODY (switch_expr), pre_p); + *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (t)); + } + else + *expr_p = SWITCH_BODY (switch_expr); + + SWITCH_BODY (switch_expr) = NULL; + } + else if (!SWITCH_LABELS (switch_expr)) + abort (); + + return ret; +} + +static enum gimplify_status +gimplify_case_label_expr (tree *expr_p) +{ + tree expr = *expr_p; + if (gimplify_ctxp->case_labels) + VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr); + else + abort (); + *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr)); + return GS_ALL_DONE; +} + +/* Gimplify a LABELED_BLOCK_EXPR into a LABEL_EXPR following + a (possibly empty) body. */ + +static enum gimplify_status +gimplify_labeled_block_expr (tree *expr_p) +{ + tree body = LABELED_BLOCK_BODY (*expr_p); + tree label = LABELED_BLOCK_LABEL (*expr_p); + tree t; + + DECL_CONTEXT (label) = current_function_decl; + t = build (LABEL_EXPR, void_type_node, label); + if (body != NULL_TREE) + t = build (COMPOUND_EXPR, void_type_node, body, t); + *expr_p = t; + + return GS_OK; +} + +/* Gimplify a EXIT_BLOCK_EXPR into a GOTO_EXPR. */ + +static enum gimplify_status +gimplify_exit_block_expr (tree *expr_p) +{ + tree labeled_block = TREE_OPERAND (*expr_p, 0); + tree label; + + /* First operand must be a LABELED_BLOCK_EXPR, which should + already be lowered (or partially lowered) when we get here. */ +#if defined ENABLE_CHECKING + if (TREE_CODE (labeled_block) != LABELED_BLOCK_EXPR) + abort (); +#endif + + label = LABELED_BLOCK_LABEL (labeled_block); + *expr_p = build1 (GOTO_EXPR, void_type_node, label); + + return GS_OK; +} + +/* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first + if necessary. */ + +tree +build_and_jump (tree *label_p) +{ + if (label_p == NULL) + /* If there's nowhere to jump, just fall through. */ + return build_empty_stmt (); + + if (*label_p == NULL_TREE) + { + tree label = create_artificial_label (); + *label_p = label; + } + + return build1 (GOTO_EXPR, void_type_node, *label_p); +} + +/* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR. + This also involves building a label to jump to and communicating it to + gimplify_loop_expr through gimplify_ctxp->exit_label. */ + +static enum gimplify_status +gimplify_exit_expr (tree *expr_p) +{ + tree cond = TREE_OPERAND (*expr_p, 0); + tree expr; + + expr = build_and_jump (&gimplify_ctxp->exit_label); + expr = build (COND_EXPR, void_type_node, cond, expr, build_empty_stmt ()); + *expr_p = expr; + + return GS_OK; +} + +/* A helper function to be called via walk_tree. Mark all labels under *TP + as being forced. To be called for DECL_INITIAL of static variables. */ + +tree +force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) +{ + if (TYPE_P (*tp)) + *walk_subtrees = 0; + if (TREE_CODE (*tp) == LABEL_DECL) + FORCED_LABEL (*tp) = 1; + + return NULL_TREE; +} + +/* Break out elements of a constructor used as an initializer into separate + MODIFY_EXPRs. + + Note that we still need to clear any elements that don't have explicit + initializers, so if not all elements are initialized we keep the + original MODIFY_EXPR, we just remove all of the constructor elements. */ + +static enum gimplify_status +gimplify_init_constructor (tree *expr_p, tree *pre_p, + tree *post_p, int want_value) +{ + tree object = TREE_OPERAND (*expr_p, 0); + tree ctor = TREE_OPERAND (*expr_p, 1); + tree type = TREE_TYPE (ctor); + enum gimplify_status ret; + tree elt_list; + + if (TREE_CODE (ctor) != CONSTRUCTOR) + return GS_UNHANDLED; + + elt_list = CONSTRUCTOR_ELTS (ctor); + + ret = GS_ALL_DONE; + switch (TREE_CODE (type)) + { + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + case ARRAY_TYPE: + { + HOST_WIDE_INT i, num_elements, num_nonzero_elements; + HOST_WIDE_INT num_nonconstant_elements; + bool cleared; + + /* Aggregate types must lower constructors to initialization of + individual elements. The exception is that a CONSTRUCTOR node + with no elements indicates zero-initialization of the whole. */ + if (elt_list == NULL) + { + if (want_value) + { + *expr_p = object; + return GS_OK; + } + else + return GS_ALL_DONE; + } + + categorize_ctor_elements (ctor, &num_nonzero_elements, + &num_nonconstant_elements); + num_elements = count_type_elements (TREE_TYPE (ctor)); + + /* If a const aggregate variable is being initialized, then it + should never be a lose to promote the variable to be static. */ + if (num_nonconstant_elements == 0 + && TREE_READONLY (object) + && TREE_CODE (object) == VAR_DECL) + { + DECL_INITIAL (object) = ctor; + TREE_STATIC (object) = 1; + if (!DECL_NAME (object)) + DECL_NAME (object) = create_tmp_var_name ("C"); + walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL); + + /* ??? C++ doesn't automatically append a .<number> to the + assembler name, and even when it does, it looks a FE private + data structures to figure out what that number should be, + which are not set for this variable. I suppose this is + important for local statics for inline functions, which aren't + "local" in the object file sense. So in order to get a unique + TU-local symbol, we must invoke the lhd version now. */ + lhd_set_decl_assembler_name (object); + + *expr_p = build_empty_stmt (); + break; + } + + /* If there are "lots" of initialized elements, and all of them + are valid address constants, then the entire initializer can + be dropped to memory, and then memcpy'd out. */ + if (num_nonconstant_elements == 0) + { + HOST_WIDE_INT size = int_size_in_bytes (type); + unsigned int align; + + /* ??? We can still get unbounded array types, at least + from the C++ front end. This seems wrong, but attempt + to work around it for now. */ + if (size < 0) + { + size = int_size_in_bytes (TREE_TYPE (object)); + if (size >= 0) + TREE_TYPE (ctor) = type = TREE_TYPE (object); + } + + /* Find the maximum alignment we can assume for the object. */ + /* ??? Make use of DECL_OFFSET_ALIGN. */ + if (DECL_P (object)) + align = DECL_ALIGN (object); + else + align = TYPE_ALIGN (type); + + if (size > 0 && !can_move_by_pieces (size, align)) + { + tree new = create_tmp_var_raw (type, "C"); + gimple_add_tmp_var (new); + TREE_STATIC (new) = 1; + TREE_READONLY (new) = 1; + DECL_INITIAL (new) = ctor; + if (align > DECL_ALIGN (new)) + { + DECL_ALIGN (new) = align; + DECL_USER_ALIGN (new) = 1; + } + walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL); + + TREE_OPERAND (*expr_p, 1) = new; + break; + } + } + + /* If there are "lots" of initialized elements, even discounting + those that are not address constants (and thus *must* be + computed at runtime), then partition the constructor into + constant and non-constant parts. Block copy the constant + parts in, then generate code for the non-constant parts. */ + /* TODO. There's code in cp/typeck.c to do this. */ + + /* If there are "lots" of zeros, then block clear the object first. */ + cleared = false; + if (num_elements - num_nonzero_elements > CLEAR_RATIO + && num_nonzero_elements < num_elements/4) + cleared = true; + + /* ??? This bit ought not be needed. For any element not present + in the initializer, we should simply set them to zero. Except + we'd need to *find* the elements that are not present, and that + requires trickery to avoid quadratic compile-time behaviour in + large cases or excessive memory use in small cases. */ + else + { + HOST_WIDE_INT len = list_length (elt_list); + if (TREE_CODE (type) == ARRAY_TYPE) + { + tree nelts = array_type_nelts (type); + if (!host_integerp (nelts, 1) + || tree_low_cst (nelts, 1) != len) + cleared = 1;; + } + else if (len != fields_length (type)) + cleared = 1; + } + + if (cleared) + { + CONSTRUCTOR_ELTS (ctor) = NULL_TREE; + append_to_statement_list (*expr_p, pre_p); + } + + for (i = 0; elt_list; i++, elt_list = TREE_CHAIN (elt_list)) + { + tree purpose, value, cref, init; + + purpose = TREE_PURPOSE (elt_list); + value = TREE_VALUE (elt_list); + + if (cleared && initializer_zerop (value)) + continue; + + if (TREE_CODE (type) == ARRAY_TYPE) + { + tree t = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object))); + + /* ??? Here's to hoping the front end fills in all of the + indicies, so we don't have to figure out what's missing + ourselves. */ + if (!purpose) + abort (); + /* ??? Need to handle this. */ + if (TREE_CODE (purpose) == RANGE_EXPR) + abort (); + + cref = build (ARRAY_REF, t, object, purpose); + } + else + { + cref = build (COMPONENT_REF, TREE_TYPE (purpose), + object, purpose); + } + + init = build (MODIFY_EXPR, TREE_TYPE (purpose), cref, value); + /* Each member initialization is a full-expression. */ + gimplify_stmt (&init); + append_to_statement_list (init, pre_p); + } + + *expr_p = build_empty_stmt (); + } + break; + + case COMPLEX_TYPE: + { + tree r, i; + + /* Extract the real and imaginary parts out of the ctor. */ + r = i = NULL_TREE; + if (elt_list) + { + r = TREE_VALUE (elt_list); + elt_list = TREE_CHAIN (elt_list); + if (elt_list) + { + i = TREE_VALUE (elt_list); + if (TREE_CHAIN (elt_list)) + abort (); + } + } + if (r == NULL || i == NULL) + { + tree zero = convert (TREE_TYPE (type), integer_zero_node); + if (r == NULL) + r = zero; + if (i == NULL) + i = zero; + } + + /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to + represent creation of a complex value. */ + if (TREE_CONSTANT (r) && TREE_CONSTANT (i)) + { + ctor = build_complex (type, r, i); + TREE_OPERAND (*expr_p, 1) = ctor; + } + else + { + ctor = build (COMPLEX_EXPR, type, r, i); + TREE_OPERAND (*expr_p, 1) = ctor; + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p, + is_gimple_rhs, fb_rvalue); + } + } + break; + + case VECTOR_TYPE: + /* Go ahead and simplify constant constructors to VECTOR_CST. */ + if (TREE_CONSTANT (ctor)) + TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list); + else + { + /* Vector types use CONSTRUCTOR all the way through gimple + compilation as a general initializer. */ + for (; elt_list; elt_list = TREE_CHAIN (elt_list)) + { + enum gimplify_status tret; + tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p, + is_gimple_constructor_elt, fb_rvalue); + if (tret == GS_ERROR) + ret = GS_ERROR; + } + } + break; + + default: + /* So how did we get a CONSTRUCTOR for a scalar type? */ + abort (); + } + + if (ret == GS_ERROR) + return GS_ERROR; + else if (want_value) + { + append_to_statement_list (*expr_p, pre_p); + *expr_p = object; + return GS_OK; + } + else + return GS_ALL_DONE; +} + +/* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is + different from its canonical type, wrap the whole thing inside a + NOP_EXPR and force the type of the COMPONENT_REF to be the canonical + type. + + The canonical type of a COMPONENT_REF is the type of the field being + referenced--unless the field is a bit-field which can be read directly + in a smaller mode, in which case the canonical type is the + sign-appropriate type corresponding to that mode. */ + +static void +canonicalize_component_ref (tree *expr_p) +{ + tree expr = *expr_p; + tree type; + + if (TREE_CODE (expr) != COMPONENT_REF) + abort (); + + if (INTEGRAL_TYPE_P (TREE_TYPE (expr))) + type = TREE_TYPE (get_unwidened (expr, NULL_TREE)); + else + type = TREE_TYPE (TREE_OPERAND (expr, 1)); + + if (TREE_TYPE (expr) != type) + { + tree old_type = TREE_TYPE (expr); + + /* Set the type of the COMPONENT_REF to the underlying type. */ + TREE_TYPE (expr) = type; + + /* And wrap the whole thing inside a NOP_EXPR. */ + expr = build1 (NOP_EXPR, old_type, expr); + + *expr_p = expr; + } +} + +/* If a NOP conversion is changing a pointer to array of foo to a pointer + to foo, embed that change in the ADDR_EXPR. Lest we perturb the type + system too badly, we must take extra steps to ensure that the ADDR_EXPR + and the addressed object continue to agree on types. */ +/* ??? We might could do better if we recognize + T array[N][M]; + (T *)&array + ==> + &array[0][0]; +*/ + +static void +canonicalize_addr_expr (tree* expr_p) +{ + tree expr = *expr_p; + tree ctype = TREE_TYPE (expr); + tree addr_expr = TREE_OPERAND (expr, 0); + tree atype = TREE_TYPE (addr_expr); + tree dctype, datype, ddatype, otype, obj_expr; + + /* Both cast and addr_expr types should be pointers. */ + if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype)) + return; + + /* The addr_expr type should be a pointer to an array. */ + datype = TREE_TYPE (atype); + if (TREE_CODE (datype) != ARRAY_TYPE) + return; + + /* Both cast and addr_expr types should address the same object type. */ + dctype = TREE_TYPE (ctype); + ddatype = TREE_TYPE (datype); + if (!lang_hooks.types_compatible_p (ddatype, dctype)) + return; + + /* The addr_expr and the object type should match. */ + obj_expr = TREE_OPERAND (addr_expr, 0); + otype = TREE_TYPE (obj_expr); + if (!lang_hooks.types_compatible_p (otype, datype)) + return; + + /* All checks succeeded. Build a new node to merge the cast. */ + *expr_p = build1 (ADDR_EXPR, ctype, obj_expr); +} + +/* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions + underneath as appropriate. */ + +static enum gimplify_status +gimplify_conversion (tree *expr_p) +{ + /* Strip away as many useless type conversions as possible + at the toplevel. */ + STRIP_USELESS_TYPE_CONVERSION (*expr_p); + + /* If we still have a conversion at the toplevel, then strip + away all but the outermost conversion. */ + if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR) + { + STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0)); + + /* And remove the outermost conversion if it's useless. */ + if (tree_ssa_useless_type_conversion (*expr_p)) + *expr_p = TREE_OPERAND (*expr_p, 0); + } + + /* If we still have a conversion at the toplevel, + then canonicalize some constructs. */ + if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR) + { + tree sub = TREE_OPERAND (*expr_p, 0); + + /* If a NOP conversion is changing the type of a COMPONENT_REF + expression, then canonicalize its type now in order to expose more + redundant conversions. */ + if (TREE_CODE (sub) == COMPONENT_REF) + canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0)); + + /* If a NOP conversion is changing a pointer to array of foo + to a pointer to foo, embed that change in the ADDR_EXPR. */ + else if (TREE_CODE (sub) == ADDR_EXPR) + canonicalize_addr_expr (expr_p); + } + + return GS_OK; +} + +/* Reduce MIN/MAX_EXPR to a COND_EXPR for further gimplification. */ + +static enum gimplify_status +gimplify_minimax_expr (tree *expr_p, tree *pre_p, tree *post_p) +{ + tree op1 = TREE_OPERAND (*expr_p, 0); + tree op2 = TREE_OPERAND (*expr_p, 1); + enum tree_code code; + enum gimplify_status r0, r1; + + if (TREE_CODE (*expr_p) == MIN_EXPR) + code = LE_EXPR; + else + code = GE_EXPR; + + r0 = gimplify_expr (&op1, pre_p, post_p, is_gimple_val, fb_rvalue); + r1 = gimplify_expr (&op2, pre_p, post_p, is_gimple_val, fb_rvalue); + + *expr_p = build (COND_EXPR, TREE_TYPE (*expr_p), + build (code, boolean_type_node, op1, op2), + op1, op2); + + if (r0 == GS_ERROR || r1 == GS_ERROR) + return GS_ERROR; + else + return GS_OK; +} + +/* Build an expression for the address of T. Folds away INDIRECT_REF to + avoid confusing the gimplify process. */ + +static tree +build_addr_expr_with_type (tree t, tree ptrtype) +{ + if (TREE_CODE (t) == INDIRECT_REF) + { + t = TREE_OPERAND (t, 0); + if (TREE_TYPE (t) != ptrtype) + t = build1 (NOP_EXPR, ptrtype, t); + } + else + { + tree base = t; + while (TREE_CODE (base) == COMPONENT_REF + || TREE_CODE (base) == ARRAY_REF) + base = TREE_OPERAND (base, 0); + if (DECL_P (base)) + TREE_ADDRESSABLE (base) = 1; + + t = build1 (ADDR_EXPR, ptrtype, t); + } + + return t; +} + +static tree +build_addr_expr (tree t) +{ + return build_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t))); +} + +/* Subroutine of gimplify_compound_lval and gimplify_array_ref. + Converts an ARRAY_REF to the equivalent *(&array + offset) form. */ + +static enum gimplify_status +gimplify_array_ref_to_plus (tree *expr_p, tree *pre_p, tree *post_p) +{ + tree array = TREE_OPERAND (*expr_p, 0); + tree arrtype = TREE_TYPE (array); + tree elttype = TREE_TYPE (arrtype); + tree size = size_in_bytes (elttype); + tree ptrtype = build_pointer_type (elttype); + enum tree_code add_code = PLUS_EXPR; + tree idx = TREE_OPERAND (*expr_p, 1); + tree minidx, offset, addr, result; + enum gimplify_status ret; + + /* If the array domain does not start at zero, apply the offset. */ + minidx = TYPE_DOMAIN (arrtype); + if (minidx) + { + minidx = TYPE_MIN_VALUE (minidx); + if (minidx && !integer_zerop (minidx)) + { + idx = convert (TREE_TYPE (minidx), idx); + idx = fold (build (MINUS_EXPR, TREE_TYPE (minidx), idx, minidx)); + } + } + + /* If the index is negative -- a technically invalid situation now + that we've biased the index back to zero -- then casting it to + unsigned has ill effects. In particular, -1*4U/4U != -1. + Represent this as a subtraction of a positive rather than addition + of a negative. This will prevent any conversion back to ARRAY_REF + from getting the wrong results from the division. */ + if (TREE_CODE (idx) == INTEGER_CST && tree_int_cst_sgn (idx) < 0) + { + idx = fold (build1 (NEGATE_EXPR, TREE_TYPE (idx), idx)); + add_code = MINUS_EXPR; + } + + /* Pointer arithmetic must be done in sizetype. */ + idx = convert (sizetype, idx); + + /* Convert the index to a byte offset. */ + offset = size_binop (MULT_EXPR, size, idx); + + ret = gimplify_expr (&array, pre_p, post_p, is_gimple_min_lval, fb_lvalue); + if (ret == GS_ERROR) + return ret; + + addr = build_addr_expr_with_type (array, ptrtype); + result = fold (build (add_code, ptrtype, addr, offset)); + *expr_p = build1 (INDIRECT_REF, elttype, result); + + return GS_OK; +} + +/* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR + node pointed by EXPR_P. + + compound_lval + : min_lval '[' val ']' + | min_lval '.' ID + | compound_lval '[' val ']' + | compound_lval '.' ID + + This is not part of the original SIMPLE definition, which separates + array and member references, but it seems reasonable to handle them + together. Also, this way we don't run into problems with union + aliasing; gcc requires that for accesses through a union to alias, the + union reference must be explicit, which was not always the case when we + were splitting up array and member refs. + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. + + POST_P points to the list where side effects that must happen after + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_compound_lval (tree *expr_p, tree *pre_p, + tree *post_p, int want_lvalue) +{ + tree *p; + enum tree_code code; + varray_type stack; + enum gimplify_status ret; + +#if defined ENABLE_CHECKING + if (TREE_CODE (*expr_p) != ARRAY_REF + && TREE_CODE (*expr_p) != COMPONENT_REF + && TREE_CODE (*expr_p) != REALPART_EXPR + && TREE_CODE (*expr_p) != IMAGPART_EXPR) + abort (); +#endif + + code = ERROR_MARK; /* [GIMPLE] Avoid uninitialized use warning. */ + + /* Create a stack of the subexpressions so later we can walk them in + order from inner to outer. */ + VARRAY_TREE_INIT (stack, 10, "stack"); + + for (p = expr_p; + TREE_CODE (*p) == ARRAY_REF + || TREE_CODE (*p) == COMPONENT_REF + || TREE_CODE (*p) == REALPART_EXPR + || TREE_CODE (*p) == IMAGPART_EXPR; + p = &TREE_OPERAND (*p, 0)) + { + code = TREE_CODE (*p); + if (code == ARRAY_REF) + { + tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*p, 0))); + if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype))) + /* If the size of the array elements is not constant, + computing the offset is non-trivial, so expose it. */ + break; + } + VARRAY_PUSH_TREE (stack, *p); + } + + /* Now 'p' points to the first bit that isn't a ref, 'code' is the + TREE_CODE of the last bit that was, and 'stack' is a stack of pointers + to all the refs we've walked through. + + Gimplify the base, and then process each of the outer nodes from left + to right. */ + ret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, + code != ARRAY_REF ? fb_either : fb_lvalue); + + for (; VARRAY_ACTIVE_SIZE (stack) > 0; ) + { + tree t = VARRAY_TOP_TREE (stack); + if (TREE_CODE (t) == ARRAY_REF) + { + /* Gimplify the dimension. */ + enum gimplify_status tret; + /* Temporary fix for gcc.c-torture/execute/20040313-1.c. + Gimplify non-constant array indices into a temporary + variable. + FIXME - The real fix is to gimplify post-modify + expressions into a minimal gimple lvalue. However, that + exposes bugs in alias analysis. The alias analyzer does + not handle &PTR->FIELD very well. Will fix after the + branch is merged into mainline (dnovillo 2004-05-03). */ + if (!is_gimple_min_invariant (TREE_OPERAND (t, 1))) + { + tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p, + is_gimple_tmp_var, fb_rvalue); + if (tret == GS_ERROR) + ret = GS_ERROR; + } + } + recalculate_side_effects (t); + VARRAY_POP (stack); + } + + /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */ + if (!want_lvalue && TREE_CODE (*expr_p) == COMPONENT_REF) + { + canonicalize_component_ref (expr_p); + ret = MIN (ret, GS_OK); + } + + return ret; +} + +/* Re-write the ARRAY_REF node pointed by EXPR_P. + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. + + POST_P points to the list where side effects that must happen after + *EXPR_P should be stored. + + FIXME: ARRAY_REF currently doesn't accept a pointer as the array + argument, so this gimplification uses an INDIRECT_REF of ARRAY_TYPE. + ARRAY_REF should be extended. */ + +static enum gimplify_status +gimplify_array_ref (tree *expr_p, tree *pre_p, + tree *post_p, int want_lvalue) +{ + tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*expr_p, 0))); + if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype))) + /* If the size of the array elements is not constant, + computing the offset is non-trivial, so expose it. */ + return gimplify_array_ref_to_plus (expr_p, pre_p, post_p); + else + /* Handle array and member refs together for now. When alias analysis + improves, we may want to go back to handling them separately. */ + return gimplify_compound_lval (expr_p, pre_p, post_p, want_lvalue); +} + +/* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=). + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. + + POST_P points to the list where side effects that must happen after + *EXPR_P should be stored. + + WANT_VALUE is nonzero iff we want to use the value of this expression + in another expression. */ + +static enum gimplify_status +gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p, + int want_value) +{ + enum tree_code code; + tree lhs, lvalue, rhs, t1; + bool postfix; + enum tree_code arith_code; + enum gimplify_status ret; + + code = TREE_CODE (*expr_p); + +#if defined ENABLE_CHECKING + if (code != POSTINCREMENT_EXPR + && code != POSTDECREMENT_EXPR + && code != PREINCREMENT_EXPR + && code != PREDECREMENT_EXPR) + abort (); +#endif + + /* Prefix or postfix? */ + if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) + /* Faster to treat as prefix if result is not used. */ + postfix = want_value; + else + postfix = false; + + /* Add or subtract? */ + if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) + arith_code = PLUS_EXPR; + else + arith_code = MINUS_EXPR; + + /* Gimplify the LHS into a GIMPLE lvalue. */ + lvalue = TREE_OPERAND (*expr_p, 0); + ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue); + if (ret == GS_ERROR) + return ret; + + /* Extract the operands to the arithmetic operation. */ + lhs = lvalue; + rhs = TREE_OPERAND (*expr_p, 1); + + /* For postfix operator, we evaluate the LHS to an rvalue and then use + that as the result value and in the postqueue operation. */ + if (postfix) + { + ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue); + if (ret == GS_ERROR) + return ret; + } + + t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs); + t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1); + + if (postfix) + { + gimplify_stmt (&t1); + append_to_statement_list (t1, post_p); + *expr_p = lhs; + return GS_ALL_DONE; + } + else + { + *expr_p = t1; + return GS_OK; + } +} + +/* Gimplify the CALL_EXPR node pointed by EXPR_P. + + call_expr + : ID '(' arglist ')' + + arglist + : arglist ',' val + | val + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_call_expr (tree *expr_p, tree *pre_p, bool (*gimple_test_f) (tree)) +{ + tree decl; + tree arglist; + enum gimplify_status ret; + +#if defined ENABLE_CHECKING + if (TREE_CODE (*expr_p) != CALL_EXPR) + abort (); +#endif + + /* For reliable diagnostics during inlining, it is necessary that + every call_expr be annotated with file and line. */ + if (!EXPR_LOCUS (*expr_p)) + annotate_with_locus (*expr_p, input_location); + + /* This may be a call to a builtin function. + + Builtin function calls may be transformed into different + (and more efficient) builtin function calls under certain + circumstances. Unfortunately, gimplification can muck things + up enough that the builtin expanders are not aware that certain + transformations are still valid. + + So we attempt transformation/gimplification of the call before + we gimplify the CALL_EXPR. At this time we do not manage to + transform all calls in the same manner as the expanders do, but + we do transform most of them. */ + decl = get_callee_fndecl (*expr_p); + if (decl && DECL_BUILT_IN (decl)) + { + tree new; + + /* If it is allocation of stack, record the need to restore the memory + when the enclosing bind_expr is exited. */ + if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_ALLOC) + gimplify_ctxp->save_stack = true; + + /* If it is restore of the stack, reset it, since it means we are + regimplifying the bind_expr. Note that we use the fact that + for try_finally_expr, try part is processed first. */ + if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_RESTORE) + gimplify_ctxp->save_stack = false; + + new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt); + + if (new && new != *expr_p) + { + /* There was a transformation of this call which computes the + same value, but in a more efficient way. Return and try + again. */ + *expr_p = new; + return GS_OK; + } + } + + /* There is a sequence point before the call, so any side effects in + the calling expression must occur before the actual call. Force + gimplify_expr to use an internal post queue. */ + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL, + is_gimple_val, fb_rvalue); + + if (PUSH_ARGS_REVERSED) + TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1)); + for (arglist = TREE_OPERAND (*expr_p, 1); arglist; + arglist = TREE_CHAIN (arglist)) + { + enum gimplify_status t; + + /* There is a sequence point before a function call. Side effects in + the argument list must occur before the actual call. So, when + gimplifying arguments, force gimplify_expr to use an internal + post queue which is then appended to the end of PRE_P. */ + t = gimplify_expr (&TREE_VALUE (arglist), pre_p, NULL, is_gimple_val, + fb_rvalue); + + if (t == GS_ERROR) + ret = GS_ERROR; + } + if (PUSH_ARGS_REVERSED) + TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1)); + + /* Try this again in case gimplification exposed something. */ + if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl)) + { + tree new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt); + + if (new && new != *expr_p) + { + /* There was a transformation of this call which computes the + same value, but in a more efficient way. Return and try + again. */ + *expr_p = new; + return GS_OK; + } + } + + /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its + decl. This allows us to eliminate redundant or useless + calls to "const" functions. */ + if (TREE_CODE (*expr_p) == CALL_EXPR + && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE))) + TREE_SIDE_EFFECTS (*expr_p) = 0; + + return ret; +} + +/* Handle shortcut semantics in the predicate operand of a COND_EXPR by + rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs. + + TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the + condition is true or false, respectively. If null, we should generate + our own to skip over the evaluation of this specific expression. + + This function is the tree equivalent of do_jump. + + shortcut_cond_r should only be called by shortcut_cond_expr. */ + +static tree +shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p) +{ + tree local_label = NULL_TREE; + tree t, expr = NULL; + + /* OK, it's not a simple case; we need to pull apart the COND_EXPR to + retain the shortcut semantics. Just insert the gotos here; + shortcut_cond_expr will append the real blocks later. */ + if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR) + { + /* Turn if (a && b) into + + if (a); else goto no; + if (b) goto yes; else goto no; + (no:) */ + + if (false_label_p == NULL) + false_label_p = &local_label; + + t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p); + append_to_statement_list (t, &expr); + + t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, + false_label_p); + append_to_statement_list (t, &expr); + } + else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR) + { + /* Turn if (a || b) into + + if (a) goto yes; + if (b) goto yes; else goto no; + (yes:) */ + + if (true_label_p == NULL) + true_label_p = &local_label; + + t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL); + append_to_statement_list (t, &expr); + + t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, + false_label_p); + append_to_statement_list (t, &expr); + } + else if (TREE_CODE (pred) == COND_EXPR) + { + /* As long as we're messing with gotos, turn if (a ? b : c) into + if (a) + if (b) goto yes; else goto no; + else + if (c) goto yes; else goto no; */ + expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0), + shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, + false_label_p), + shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p, + false_label_p)); + } + else + { + expr = build (COND_EXPR, void_type_node, pred, + build_and_jump (true_label_p), + build_and_jump (false_label_p)); + } + + if (local_label) + { + t = build1 (LABEL_EXPR, void_type_node, local_label); + append_to_statement_list (t, &expr); + } + + return expr; +} + +static tree +shortcut_cond_expr (tree expr) +{ + tree pred = TREE_OPERAND (expr, 0); + tree then_ = TREE_OPERAND (expr, 1); + tree else_ = TREE_OPERAND (expr, 2); + tree true_label, false_label, end_label, t; + tree *true_label_p; + tree *false_label_p; + bool emit_end, emit_false; + + /* First do simple transformations. */ + if (!TREE_SIDE_EFFECTS (else_)) + { + /* If there is no 'else', turn (a && b) into if (a) if (b). */ + while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR) + { + TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1); + then_ = shortcut_cond_expr (expr); + pred = TREE_OPERAND (pred, 0); + expr = build (COND_EXPR, void_type_node, pred, then_, + build_empty_stmt ()); + } + } + if (!TREE_SIDE_EFFECTS (then_)) + { + /* If there is no 'then', turn + if (a || b); else d + into + if (a); else if (b); else d. */ + while (TREE_CODE (pred) == TRUTH_ORIF_EXPR) + { + TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1); + else_ = shortcut_cond_expr (expr); + pred = TREE_OPERAND (pred, 0); + expr = build (COND_EXPR, void_type_node, pred, + build_empty_stmt (), else_); + } + } + + /* If we're done, great. */ + if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR + && TREE_CODE (pred) != TRUTH_ORIF_EXPR) + return expr; + + /* Otherwise we need to mess with gotos. Change + if (a) c; else d; + to + if (a); else goto no; + c; goto end; + no: d; end: + and recursively gimplify the condition. */ + + true_label = false_label = end_label = NULL_TREE; + + /* If our arms just jump somewhere, hijack those labels so we don't + generate jumps to jumps. */ + + if (TREE_CODE (then_) == GOTO_EXPR + && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL) + { + true_label = GOTO_DESTINATION (then_); + then_ = build_empty_stmt (); + } + + if (TREE_CODE (else_) == GOTO_EXPR + && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL) + { + false_label = GOTO_DESTINATION (else_); + else_ = build_empty_stmt (); + } + + /* If we aren't hijacking a label for the 'then' branch, it falls through. */ + if (true_label) + true_label_p = &true_label; + else + true_label_p = NULL; + + /* The 'else' branch also needs a label if it contains interesting code. */ + if (false_label || TREE_SIDE_EFFECTS (else_)) + false_label_p = &false_label; + else + false_label_p = NULL; + + /* If there was nothing else in our arms, just forward the label(s). */ + if (!TREE_SIDE_EFFECTS (then_) && !TREE_SIDE_EFFECTS (else_)) + return shortcut_cond_r (pred, true_label_p, false_label_p); + + /* If our last subexpression already has a terminal label, reuse it. */ + if (TREE_SIDE_EFFECTS (else_)) + expr = expr_last (else_); + else + expr = expr_last (then_); + if (TREE_CODE (expr) == LABEL_EXPR) + end_label = LABEL_EXPR_LABEL (expr); + + /* If we don't care about jumping to the 'else' branch, jump to the end + if the condition is false. */ + if (!false_label_p) + false_label_p = &end_label; + + /* We only want to emit these labels if we aren't hijacking them. */ + emit_end = (end_label == NULL_TREE); + emit_false = (false_label == NULL_TREE); + + pred = shortcut_cond_r (pred, true_label_p, false_label_p); + + expr = NULL; + append_to_statement_list (pred, &expr); + + append_to_statement_list (then_, &expr); + if (TREE_SIDE_EFFECTS (else_)) + { + t = build_and_jump (&end_label); + append_to_statement_list (t, &expr); + if (emit_false) + { + t = build1 (LABEL_EXPR, void_type_node, false_label); + append_to_statement_list (t, &expr); + } + append_to_statement_list (else_, &expr); + } + if (emit_end && end_label) + { + t = build1 (LABEL_EXPR, void_type_node, end_label); + append_to_statement_list (t, &expr); + } + + return expr; +} + +/* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */ + +static tree +gimple_boolify (tree expr) +{ + tree type = TREE_TYPE (expr); + + if (TREE_CODE (type) == BOOLEAN_TYPE) + return expr; + + /* If this is the predicate of a COND_EXPR, it might not even be a + truthvalue yet. */ + expr = (*lang_hooks.truthvalue_conversion) (expr); + + switch (TREE_CODE (expr)) + { + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case TRUTH_XOR_EXPR: + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + /* Also boolify the arguments of truth exprs. */ + TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1)); + /* FALLTHRU */ + + case TRUTH_NOT_EXPR: + TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0)); + /* FALLTHRU */ + + case EQ_EXPR: case NE_EXPR: + case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR: + /* These expressions always produce boolean results. */ + TREE_TYPE (expr) = boolean_type_node; + return expr; + + default: + /* Other expressions that get here must have boolean values, but + might need to be converted to the appropriate mode. */ + return convert (boolean_type_node, expr); + } +} + +/* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;' + into + + if (p) if (p) + t1 = a; a; + else or else + t1 = b; b; + t1; + + The second form is used when *EXPR_P is of type void. + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target) +{ + tree expr = *expr_p; + tree tmp; + enum gimplify_status ret; + + /* If this COND_EXPR has a value, copy the values into a temporary within + the arms. */ + if (! VOID_TYPE_P (TREE_TYPE (expr))) + { + if (target) + { + tmp = target; + ret = GS_OK; + } + else + { + tmp = create_tmp_var (TREE_TYPE (expr), "iftmp"); + ret = GS_ALL_DONE; + } + + /* Build the then clause, 't1 = a;'. But don't build an assignment + if this branch is void; in C++ it can be, if it's a throw. */ + if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node) + TREE_OPERAND (expr, 1) + = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1)); + + /* Build the else clause, 't1 = b;'. */ + if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node) + TREE_OPERAND (expr, 2) + = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 2)); + + TREE_TYPE (expr) = void_type_node; + recalculate_side_effects (expr); + + /* Move the COND_EXPR to the prequeue and use the temp in its place. */ + gimplify_stmt (&expr); + append_to_statement_list (expr, pre_p); + *expr_p = tmp; + + return ret; + } + + /* Make sure the condition has BOOLEAN_TYPE. */ + TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0)); + + /* Break apart && and || conditions. */ + if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR + || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR) + { + expr = shortcut_cond_expr (expr); + + if (expr != *expr_p) + { + *expr_p = expr; + + /* We can't rely on gimplify_expr to re-gimplify the expanded + form properly, as cleanups might cause the target labels to be + wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to + set up a conditional context. */ + gimple_push_condition (); + gimplify_stmt (expr_p); + gimple_pop_condition (pre_p); + + return GS_ALL_DONE; + } + } + + /* Now do the normal gimplification. */ + ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL, + is_gimple_condexpr, fb_rvalue); + + gimple_push_condition (); + + gimplify_to_stmt_list (&TREE_OPERAND (expr, 1)); + gimplify_to_stmt_list (&TREE_OPERAND (expr, 2)); + recalculate_side_effects (expr); + + gimple_pop_condition (pre_p); + + if (ret == GS_ERROR) + ; + else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))) + ret = GS_ALL_DONE; + else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2))) + /* Rewrite "if (a); else b" to "if (!a) b" */ + { + TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0)); + ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL, + is_gimple_condexpr, fb_rvalue); + + tmp = TREE_OPERAND (expr, 1); + TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2); + TREE_OPERAND (expr, 2) = tmp; + } + else + /* Both arms are empty; replace the COND_EXPR with its predicate. */ + expr = TREE_OPERAND (expr, 0); + + *expr_p = expr; + return ret; +} + +/* Gimplify the MODIFY_EXPR node pointed by EXPR_P. + + modify_expr + : varname '=' rhs + | '*' ID '=' rhs + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. + + POST_P points to the list where side effects that must happen after + *EXPR_P should be stored. + + WANT_VALUE is nonzero iff we want to use the value of this expression + in another expression. */ + +static enum gimplify_status +gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value) +{ + tree *from_p = &TREE_OPERAND (*expr_p, 1); + tree *to_p = &TREE_OPERAND (*expr_p, 0); + enum gimplify_status ret; + +#if defined ENABLE_CHECKING + if (TREE_CODE (*expr_p) != MODIFY_EXPR && TREE_CODE (*expr_p) != INIT_EXPR) + abort (); +#endif + + /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */ + if (TREE_CODE (*expr_p) == INIT_EXPR) + TREE_SET_CODE (*expr_p, MODIFY_EXPR); + + ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue); + if (ret == GS_ERROR) + return ret; + + /* If we are initializing something from a TARGET_EXPR, strip the + TARGET_EXPR and initialize it directly. */ + /* What about code that pulls out the temp and uses it elsewhere? I + think that such code never uses the TARGET_EXPR as an initializer. If + I'm wrong, we'll abort because the temp won't have any RTL. In that + case, I guess we'll need to replace references somehow. */ + if (TREE_CODE (*from_p) == TARGET_EXPR) + *from_p = TARGET_EXPR_INITIAL (*from_p); + + /* If we're assigning from a ?: expression with ADDRESSABLE type, push + the assignment down into the branches, since we can't generate a + temporary of such a type. */ + if (TREE_CODE (*from_p) == COND_EXPR + && TREE_ADDRESSABLE (TREE_TYPE (*from_p))) + { + *expr_p = *from_p; + return gimplify_cond_expr (expr_p, pre_p, *to_p); + } + + ret = gimplify_expr (from_p, pre_p, post_p, is_gimple_rhs, fb_rvalue); + if (ret == GS_ERROR) + return ret; + + ret = gimplify_init_constructor (expr_p, pre_p, post_p, want_value); + if (ret != GS_UNHANDLED) + return ret; + + /* If the destination is already simple, nothing else needed. */ + if (is_gimple_tmp_var (*to_p)) + ret = GS_ALL_DONE; + else + { + /* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto and + the LHS is a user variable, then we need to introduce a temporary. + ie temp = RHS; LHS = temp. + + This way the optimizers can determine that the user variable is + only modified if evaluation of the RHS does not throw. + + FIXME this should be handled by the is_gimple_rhs predicate. */ + + if (TREE_CODE (*from_p) == CALL_EXPR + || (flag_non_call_exceptions && tree_could_trap_p (*from_p)) + /* If we're dealing with a renamable type, either source or dest + must be a renamed variable. */ + || (is_gimple_reg_type (TREE_TYPE (*from_p)) + && !is_gimple_reg (*to_p))) + gimplify_expr (from_p, pre_p, post_p, is_gimple_val, fb_rvalue); + + /* If the value being copied is of variable width, expose the length + if the copy by converting the whole thing to a memcpy. */ + /* ??? Except that we can't manage this with VA_ARG_EXPR. Yes, this + does leave us with an edge condition that doesn't work. The only + way out is to rearrange how VA_ARG_EXPR works. */ + if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p))) != INTEGER_CST + && TREE_CODE (*from_p) != VA_ARG_EXPR) + { + tree args, t, dest; + + t = TYPE_SIZE_UNIT (TREE_TYPE (*to_p)); + args = tree_cons (NULL, t, NULL); + t = build_addr_expr (*from_p); + args = tree_cons (NULL, t, args); + dest = build_addr_expr (*to_p); + args = tree_cons (NULL, dest, args); + t = implicit_built_in_decls[BUILT_IN_MEMCPY]; + t = build_function_call_expr (t, args); + if (want_value) + { + t = build1 (NOP_EXPR, TREE_TYPE (dest), t); + t = build1 (INDIRECT_REF, TREE_TYPE (*to_p), t); + } + *expr_p = t; + + return GS_OK; + } + + ret = want_value ? GS_OK : GS_ALL_DONE; + } + + if (want_value) + { + append_to_statement_list (*expr_p, pre_p); + *expr_p = *to_p; + } + + return ret; +} + +/* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P + points to the expression to gimplify. + + Expressions of the form 'a && b' are gimplified to: + + a && b ? true : false + + gimplify_cond_expr will do the rest. + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_boolean_expr (tree *expr_p) +{ + /* Preserve the original type of the expression. */ + tree type = TREE_TYPE (*expr_p); + + *expr_p = build (COND_EXPR, type, *expr_p, + convert (type, boolean_true_node), + convert (type, boolean_false_node)); + + return GS_OK; +} + +/* Gimplifies an expression sequence. This function gimplifies each + expression and re-writes the original expression with the last + expression of the sequence in GIMPLE form. + + PRE_P points to the list where the side effects for all the + expressions in the sequence will be emitted. + + WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */ +/* ??? Should rearrange to share the pre-queue with all the indirect + invocations of gimplify_expr. Would probably save on creations + of statement_list nodes. */ + +static enum gimplify_status +gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value) +{ + tree t = *expr_p; + + do + { + tree *sub_p = &TREE_OPERAND (t, 0); + + if (TREE_CODE (*sub_p) == COMPOUND_EXPR) + gimplify_compound_expr (sub_p, pre_p, false); + else + gimplify_stmt (sub_p); + append_to_statement_list (*sub_p, pre_p); + + t = TREE_OPERAND (t, 1); + } + while (TREE_CODE (t) == COMPOUND_EXPR); + + *expr_p = t; + if (want_value) + return GS_OK; + else + { + gimplify_stmt (expr_p); + return GS_ALL_DONE; + } +} + +/* Gimplifies a statement list. These may be created either by an + enlightend front-end, or by shortcut_cond_expr. */ + +static enum gimplify_status +gimplify_statement_list (tree *expr_p) +{ + tree_stmt_iterator i = tsi_start (*expr_p); + + while (!tsi_end_p (i)) + { + tree t; + + gimplify_stmt (tsi_stmt_ptr (i)); + + t = tsi_stmt (i); + if (TREE_CODE (t) == STATEMENT_LIST) + { + tsi_link_before (&i, t, TSI_SAME_STMT); + tsi_delink (&i); + } + else + tsi_next (&i); + } + + return GS_ALL_DONE; +} + +/* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to + gimplify. After gimplification, EXPR_P will point to a new temporary + that holds the original value of the SAVE_EXPR node. + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p) +{ + enum gimplify_status ret = GS_ALL_DONE; + tree val; + +#if defined ENABLE_CHECKING + if (TREE_CODE (*expr_p) != SAVE_EXPR) + abort (); +#endif + + val = TREE_OPERAND (*expr_p, 0); + + /* If the operand is already a GIMPLE temporary, just re-write the + SAVE_EXPR node. */ + if (is_gimple_tmp_var (val)) + *expr_p = val; + /* The operand may be a void-valued expression such as SAVE_EXPRs + generated by the Java frontend for class initialization. It is + being executed only for its side-effects. */ + else if (TREE_TYPE (val) == void_type_node) + { + tree body = TREE_OPERAND (*expr_p, 0); + ret = gimplify_expr (& body, pre_p, post_p, is_gimple_stmt, fb_none); + append_to_statement_list (body, pre_p); + *expr_p = build_empty_stmt (); + } + else + *expr_p = TREE_OPERAND (*expr_p, 0) + = get_initialized_tmp_var (val, pre_p, post_p); + + return ret; +} + +/* Re-write the ADDR_EXPR node pointed by EXPR_P + + unary_expr + : ... + | '&' varname + ... + + PRE_P points to the list where side effects that must happen before + *EXPR_P should be stored. + + POST_P points to the list where side effects that must happen after + *EXPR_P should be stored. */ + +static enum gimplify_status +gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p) +{ + tree expr = *expr_p; + tree op0 = TREE_OPERAND (expr, 0); + enum gimplify_status ret; + + switch (TREE_CODE (op0)) + { + case INDIRECT_REF: + /* Check if we are dealing with an expression of the form '&*ptr'. + While the front end folds away '&*ptr' into 'ptr', these + expressions may be generated internally by the compiler (e.g., + builtins like __builtin_va_end). */ + *expr_p = TREE_OPERAND (op0, 0); + ret = GS_OK; + break; + + case ARRAY_REF: + /* Fold &a[6] to (&a + 6). */ + ret = gimplify_array_ref_to_plus (&TREE_OPERAND (expr, 0), + pre_p, post_p); + + /* This added an INDIRECT_REF. Fold it away. */ + op0 = TREE_OPERAND (TREE_OPERAND (expr, 0), 0); + + *expr_p = op0; + break; + + default: + /* We use fb_either here because the C frontend sometimes takes + the address of a call that returns a struct. */ + ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p, + is_gimple_addr_expr_arg, fb_either); + if (ret != GS_ERROR) + { + /* At this point, the argument of the ADDR_EXPR should be + sufficiently simple that there are never side effects. */ + /* ??? Could split out the decision code from build1 to verify. */ + TREE_SIDE_EFFECTS (expr) = 0; + + /* Make sure TREE_INVARIANT/TREE_CONSTANT is set properly. */ + recompute_tree_invarant_for_addr_expr (expr); + + /* Mark the RHS addressable. */ + (*lang_hooks.mark_addressable) (TREE_OPERAND (expr, 0)); + } + break; + } + + /* If the operand is gimplified into a _DECL, mark the address expression + as TREE_INVARIANT. */ + if (DECL_P (TREE_OPERAND (expr, 0))) + TREE_INVARIANT (expr) = 1; + + return ret; +} + +/* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple + value; output operands should be a gimple lvalue. */ + +static enum gimplify_status +gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p) +{ + tree expr = *expr_p; + int noutputs = list_length (ASM_OUTPUTS (expr)); + const char **oconstraints + = (const char **) alloca ((noutputs) * sizeof (const char *)); + int i; + tree link; + const char *constraint; + bool allows_mem, allows_reg, is_inout; + enum gimplify_status ret, tret; + + ASM_STRING (expr) + = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr), + ASM_INPUTS (expr)); + + ret = GS_ALL_DONE; + for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link)) + { + oconstraints[i] = constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + + parse_output_constraint (&constraint, i, 0, 0, + &allows_mem, &allows_reg, &is_inout); + + if (!allows_reg && allows_mem) + (*lang_hooks.mark_addressable) (TREE_VALUE (link)); + + tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p, + is_inout ? is_gimple_min_lval : is_gimple_lvalue, + fb_lvalue | fb_mayfail); + if (tret == GS_ERROR) + { + error ("invalid lvalue in asm output %d", i); + ret = tret; + } + + if (is_inout) + { + /* An input/output operand. To give the optimizers more + flexibility, split it into separate input and output + operands. */ + tree input; + char buf[10]; + size_t constraint_len = strlen (constraint); + + /* Turn the in/out constraint into an output constraint. */ + char *p = xstrdup (constraint); + p[0] = '='; + TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p); + free (p); + + /* And add a matching input constraint. */ + if (allows_reg) + { + sprintf (buf, "%d", i); + input = build_string (strlen (buf), buf); + } + else + input = build_string (constraint_len - 1, constraint + 1); + input = build_tree_list (build_tree_list (NULL_TREE, input), + unshare_expr (TREE_VALUE (link))); + ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input); + } + } + + for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link)) + { + constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + parse_input_constraint (&constraint, 0, 0, noutputs, 0, + oconstraints, &allows_mem, &allows_reg); + + /* If the operand is a memory input, it should be an lvalue. */ + if (!allows_reg && allows_mem) + { + (*lang_hooks.mark_addressable) (TREE_VALUE (link)); + tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p, + is_gimple_lvalue, fb_lvalue | fb_mayfail); + if (tret == GS_ERROR) + { + error ("memory input %d is not directly addressable", i); + ret = tret; + } + } + else + { + tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p, + is_gimple_val, fb_rvalue); + if (tret == GS_ERROR) + ret = tret; + } + } + + return ret; +} + +/* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding + WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while + gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we + return to this function. + + FIXME should we complexify the prequeue handling instead? Or use flags + for all the cleanups and let the optimizer tighten them up? The current + code seems pretty fragile; it will break on a cleanup within any + non-conditional nesting. But any such nesting would be broken, anyway; + we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct + and continues out of it. We can do that at the RTL level, though, so + having an optimizer to tighten up try/finally regions would be a Good + Thing. */ + +static enum gimplify_status +gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p) +{ + tree_stmt_iterator iter; + tree body; + + tree temp = voidify_wrapper_expr (*expr_p); + + /* We only care about the number of conditions between the innermost + CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */ + int old_conds = gimplify_ctxp->conditions; + gimplify_ctxp->conditions = 0; + + body = TREE_OPERAND (*expr_p, 0); + gimplify_to_stmt_list (&body); + + gimplify_ctxp->conditions = old_conds; + + for (iter = tsi_start (body); !tsi_end_p (iter); ) + { + tree *wce_p = tsi_stmt_ptr (iter); + tree wce = *wce_p; + + if (TREE_CODE (wce) == WITH_CLEANUP_EXPR) + { + if (tsi_one_before_end_p (iter)) + { + tsi_link_before (&iter, TREE_OPERAND (wce, 1), TSI_SAME_STMT); + tsi_delink (&iter); + break; + } + else + { + tree sl, tfe; + + sl = tsi_split_statement_list_after (&iter); + tfe = build (TRY_FINALLY_EXPR, void_type_node, sl, NULL_TREE); + append_to_statement_list (TREE_OPERAND (wce, 1), + &TREE_OPERAND (tfe, 1)); + *wce_p = tfe; + iter = tsi_start (sl); + } + } + else + tsi_next (&iter); + } + + if (temp) + { + *expr_p = temp; + append_to_statement_list (body, pre_p); + return GS_OK; + } + else + { + *expr_p = body; + return GS_ALL_DONE; + } +} + +/* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP + is the cleanup action required. */ + +static void +gimple_push_cleanup (tree var, tree cleanup, tree *pre_p) +{ + tree wce; + + /* Errors can result in improperly nested cleanups. Which results in + confusion when trying to resolve the WITH_CLEANUP_EXPR. */ + if (errorcount || sorrycount) + return; + + if (gimple_conditional_context ()) + { + /* If we're in a conditional context, this is more complex. We only + want to run the cleanup if we actually ran the initialization that + necessitates it, but we want to run it after the end of the + conditional context. So we wrap the try/finally around the + condition and use a flag to determine whether or not to actually + run the destructor. Thus + + test ? f(A()) : 0 + + becomes (approximately) + + flag = 0; + try { + if (test) { A::A(temp); flag = 1; val = f(temp); } + else { val = 0; } + } finally { + if (flag) A::~A(temp); + } + val + */ + + tree flag = create_tmp_var (boolean_type_node, "cleanup"); + tree ffalse = build (MODIFY_EXPR, void_type_node, flag, + boolean_false_node); + tree ftrue = build (MODIFY_EXPR, void_type_node, flag, + boolean_true_node); + cleanup = build (COND_EXPR, void_type_node, flag, cleanup, + build_empty_stmt ()); + wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE, + cleanup, NULL_TREE); + append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups); + append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups); + append_to_statement_list (ftrue, pre_p); + + /* Because of this manipulation, and the EH edges that jump + threading cannot redirect, the temporary (VAR) will appear + to be used uninitialized. Don't warn. */ + TREE_NO_WARNING (var) = 1; + } + else + { + wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE, + cleanup, NULL_TREE); + append_to_statement_list (wce, pre_p); + } + + gimplify_stmt (&TREE_OPERAND (wce, 1)); +} + +/* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */ + +static enum gimplify_status +gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p) +{ + tree targ = *expr_p; + tree temp = TARGET_EXPR_SLOT (targ); + tree init = TARGET_EXPR_INITIAL (targ); + enum gimplify_status ret; + + if (init) + { + /* TARGET_EXPR temps aren't part of the enclosing block, so add it to the + temps list. */ + gimple_add_tmp_var (temp); + + /* Build up the initialization and add it to pre_p. */ + init = build (MODIFY_EXPR, void_type_node, temp, init); + ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none); + if (ret == GS_ERROR) + return GS_ERROR; + + append_to_statement_list (init, pre_p); + + /* If needed, push the cleanup for the temp. */ + if (TARGET_EXPR_CLEANUP (targ)) + { + gimplify_stmt (&TARGET_EXPR_CLEANUP (targ)); + gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), pre_p); + } + + /* Only expand this once. */ + TREE_OPERAND (targ, 3) = init; + TARGET_EXPR_INITIAL (targ) = NULL_TREE; + } + else if (!temp->decl.seen_in_bind_expr) + /* We should have expanded this before. */ + abort (); + + *expr_p = temp; + return GS_OK; +} + +/* Gimplification of expression trees. */ + +/* Gimplify an expression which appears at statement context; usually, this + means replacing it with a suitably gimple COMPOUND_EXPR. */ + +void +gimplify_stmt (tree *stmt_p) +{ + gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none); + if (!*stmt_p) + *stmt_p = alloc_stmt_list (); +} + +/* Similarly, but force the result to be a STATEMENT_LIST. */ + +void +gimplify_to_stmt_list (tree *stmt_p) +{ + gimplify_stmt (stmt_p); + if (TREE_CODE (*stmt_p) != STATEMENT_LIST) + { + tree t = *stmt_p; + *stmt_p = NULL; + append_to_statement_list (t, stmt_p); + } +} + + +/* Gimplifies the expression tree pointed by EXPR_P. Return 0 if + gimplification failed. + + PRE_P points to the list where side effects that must happen before + EXPR should be stored. + + POST_P points to the list where side effects that must happen after + EXPR should be stored, or NULL if there is no suitable list. In + that case, we copy the result to a temporary, emit the + post-effects, and then return the temporary. + + GIMPLE_TEST_F points to a function that takes a tree T and + returns nonzero if T is in the GIMPLE form requested by the + caller. The GIMPLE predicates are in tree-simple.c. + + This test is used twice. Before gimplification, the test is + invoked to determine whether *EXPR_P is already gimple enough. If + that fails, *EXPR_P is gimplified according to its code and + GIMPLE_TEST_F is called again. If the test still fails, then a new + temporary variable is created and assigned the value of the + gimplified expression. + + FALLBACK tells the function what sort of a temporary we want. If the 1 + bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK. + If both are set, either is OK, but an lvalue is preferable. + + The return value is either GS_ERROR or GS_ALL_DONE, since this function + iterates until solution. */ + +enum gimplify_status +gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p, + bool (* gimple_test_f) (tree), fallback_t fallback) +{ + tree tmp; + tree internal_pre = NULL_TREE; + tree internal_post = NULL_TREE; + tree save_expr; + int is_statement = (pre_p == NULL); + location_t *locus; + location_t saved_location; + enum gimplify_status ret; + + save_expr = *expr_p; + if (save_expr == NULL_TREE) + return GS_ALL_DONE; + + /* We used to check the predicate here and return immediately if it + succeeds. This is wrong; the design is for gimplification to be + idempotent, and for the predicates to only test for valid forms, not + whether they are fully simplified. */ + + /* Set up our internal queues if needed. */ + if (pre_p == NULL) + pre_p = &internal_pre; + if (post_p == NULL) + post_p = &internal_post; + + saved_location = input_location; + if (save_expr == error_mark_node) + locus = NULL; + else + locus = EXPR_LOCUS (save_expr); + if (locus) + input_location = *locus; + + /* Loop over the specific gimplifiers until the toplevel node + remains the same. */ + do + { + /* Strip any uselessness. */ + STRIP_MAIN_TYPE_NOPS (*expr_p); + + /* Remember the expr. */ + save_expr = *expr_p; + + /* Die, die, die, my darling. */ + if (save_expr == error_mark_node + || TREE_TYPE (save_expr) == error_mark_node) + { + ret = GS_ERROR; + break; + } + + /* Do any language-specific gimplification. */ + ret = (*lang_hooks.gimplify_expr) (expr_p, pre_p, post_p); + if (ret == GS_OK) + { + if (*expr_p == NULL_TREE) + break; + if (*expr_p != save_expr) + continue; + } + else if (ret != GS_UNHANDLED) + break; + + ret = GS_OK; + switch (TREE_CODE (*expr_p)) + { + /* First deal with the special cases. */ + + case POSTINCREMENT_EXPR: + case POSTDECREMENT_EXPR: + case PREINCREMENT_EXPR: + case PREDECREMENT_EXPR: + ret = gimplify_self_mod_expr (expr_p, pre_p, post_p, + fallback != fb_none); + break; + + case ARRAY_REF: + ret = gimplify_array_ref (expr_p, pre_p, post_p, + fallback & fb_lvalue); + break; + + case COMPONENT_REF: + ret = gimplify_compound_lval (expr_p, pre_p, post_p, + fallback & fb_lvalue); + break; + + case COND_EXPR: + ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE); + break; + + case CALL_EXPR: + ret = gimplify_call_expr (expr_p, pre_p, gimple_test_f); + break; + + case TREE_LIST: + abort (); + + case COMPOUND_EXPR: + ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none); + break; + + case REALPART_EXPR: + case IMAGPART_EXPR: + ret = gimplify_compound_lval (expr_p, pre_p, post_p, + fallback & fb_lvalue); + break; + + case MODIFY_EXPR: + case INIT_EXPR: + ret = gimplify_modify_expr (expr_p, pre_p, post_p, + fallback != fb_none); + break; + + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + ret = gimplify_boolean_expr (expr_p); + break; + + case TRUTH_NOT_EXPR: + TREE_OPERAND (*expr_p, 0) + = gimple_boolify (TREE_OPERAND (*expr_p, 0)); + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p, + is_gimple_val, fb_rvalue); + recalculate_side_effects (*expr_p); + break; + + case ADDR_EXPR: + ret = gimplify_addr_expr (expr_p, pre_p, post_p); + break; + + case VA_ARG_EXPR: + /* Mark any _DECL inside the operand as volatile to avoid the + optimizers messing around with it. FIXME: Remove this once + VA_ARG_EXPRs are properly lowered. */ + walk_tree (&TREE_OPERAND (*expr_p, 0), mark_decls_volatile_r, + NULL, NULL); + + /* va_arg expressions are in GIMPLE form already. */ + ret = GS_ALL_DONE; + break; + + case CONVERT_EXPR: + case NOP_EXPR: + if (IS_EMPTY_STMT (*expr_p)) + { + ret = GS_ALL_DONE; + break; + } + + if (VOID_TYPE_P (TREE_TYPE (*expr_p)) + || fallback == fb_none) + { + /* Just strip a conversion to void (or in void context) and + try again. */ + *expr_p = TREE_OPERAND (*expr_p, 0); + break; + } + + ret = gimplify_conversion (expr_p); + if (ret == GS_ERROR) + break; + if (*expr_p != save_expr) + break; + /* FALLTHRU */ + + case FIX_TRUNC_EXPR: + case FIX_CEIL_EXPR: + case FIX_FLOOR_EXPR: + case FIX_ROUND_EXPR: + /* unary_expr: ... | '(' cast ')' val | ... */ + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p, + is_gimple_val, fb_rvalue); + recalculate_side_effects (*expr_p); + break; + + case INDIRECT_REF: + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p, + is_gimple_reg, fb_rvalue); + recalculate_side_effects (*expr_p); + break; + + /* Constants need not be gimplified. */ + case INTEGER_CST: + case REAL_CST: + case STRING_CST: + case COMPLEX_CST: + case VECTOR_CST: + ret = GS_ALL_DONE; + break; + + case CONST_DECL: + *expr_p = DECL_INITIAL (*expr_p); + break; + + case EXC_PTR_EXPR: + /* FIXME make this a decl. */ + ret = GS_ALL_DONE; + break; + + case BIND_EXPR: + ret = gimplify_bind_expr (expr_p, pre_p); + break; + + case LOOP_EXPR: + ret = gimplify_loop_expr (expr_p, pre_p); + break; + + case SWITCH_EXPR: + ret = gimplify_switch_expr (expr_p, pre_p); + break; + + case LABELED_BLOCK_EXPR: + ret = gimplify_labeled_block_expr (expr_p); + break; + + case EXIT_BLOCK_EXPR: + ret = gimplify_exit_block_expr (expr_p); + break; + + case EXIT_EXPR: + ret = gimplify_exit_expr (expr_p); + break; + + case GOTO_EXPR: + /* If the target is not LABEL, then it is a computed jump + and the target needs to be gimplified. */ + if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL) + ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p, + NULL, is_gimple_val, fb_rvalue); + break; + + case LABEL_EXPR: + ret = GS_ALL_DONE; +#ifdef ENABLE_CHECKING + if (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) != current_function_decl) + abort (); +#endif + break; + + case CASE_LABEL_EXPR: + ret = gimplify_case_label_expr (expr_p); + break; + + case RETURN_EXPR: + ret = gimplify_return_expr (*expr_p, pre_p); + break; + + case CONSTRUCTOR: + /* Don't reduce this in place; let gimplify_init_constructor work + its magic. */ + ret = GS_ALL_DONE; + break; + + /* The following are special cases that are not handled by the + original GIMPLE grammar. */ + + /* SAVE_EXPR nodes are converted into a GIMPLE identifier and + eliminated. */ + case SAVE_EXPR: + ret = gimplify_save_expr (expr_p, pre_p, post_p); + break; + + case BIT_FIELD_REF: + { + enum gimplify_status r0, r1, r2; + + r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p, + is_gimple_min_lval, fb_either); + r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p, + is_gimple_val, fb_rvalue); + r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p, + is_gimple_val, fb_rvalue); + recalculate_side_effects (*expr_p); + + ret = MIN (r0, MIN (r1, r2)); + } + break; + + case NON_LVALUE_EXPR: + /* This should have been stripped above. */ + abort (); + break; + + case ASM_EXPR: + ret = gimplify_asm_expr (expr_p, pre_p, post_p); + break; + + case TRY_FINALLY_EXPR: + case TRY_CATCH_EXPR: + gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0)); + gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1)); + ret = GS_ALL_DONE; + break; + + case CLEANUP_POINT_EXPR: + ret = gimplify_cleanup_point_expr (expr_p, pre_p); + break; + + case TARGET_EXPR: + ret = gimplify_target_expr (expr_p, pre_p, post_p); + break; + + case CATCH_EXPR: + gimplify_to_stmt_list (&CATCH_BODY (*expr_p)); + ret = GS_ALL_DONE; + break; + + case EH_FILTER_EXPR: + gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p)); + ret = GS_ALL_DONE; + break; + + case VTABLE_REF: + /* This moves much of the actual computation out of the + VTABLE_REF. Perhaps this should be revisited once we want to + do clever things with VTABLE_REFs. */ + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p, + is_gimple_min_lval, fb_lvalue); + break; + + case MIN_EXPR: + case MAX_EXPR: + ret = gimplify_minimax_expr (expr_p, pre_p, post_p); + break; + + case LABEL_DECL: + /* We get here when taking the address of a label. We mark + the label as "forced"; meaning it can never be removed and + it is a potential target for any computed goto. */ + FORCED_LABEL (*expr_p) = 1; + ret = GS_ALL_DONE; + break; + + case STATEMENT_LIST: + ret = gimplify_statement_list (expr_p); + break; + + case VAR_DECL: + /* ??? If this is a local variable, and it has not been seen in any + outer BIND_EXPR, then it's probably the result of a duplicate + declaration, for which we've already issued an error. It would + be really nice if the front end wouldn't leak these at all. + Currently the only known culprit is C++ destructors, as seen + in g++.old-deja/g++.jason/binding.C. */ + tmp = *expr_p; + if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp) + && decl_function_context (tmp) == current_function_decl + && !tmp->decl.seen_in_bind_expr) + { +#ifdef ENABLE_CHECKING + if (!errorcount && !sorrycount) + abort (); +#endif + ret = GS_ERROR; + } + else + ret = GS_ALL_DONE; + break; + + default: + /* If *EXPR_P does not need to be special-cased, handle it + according to its class. */ + if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '1') + ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, + post_p, is_gimple_val, fb_rvalue); + else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '2' + || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<' + || TREE_CODE (*expr_p) == TRUTH_AND_EXPR + || TREE_CODE (*expr_p) == TRUTH_OR_EXPR + || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR) + { + enum gimplify_status r0, r1; + + r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, + post_p, is_gimple_val, fb_rvalue); + r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, + post_p, is_gimple_val, fb_rvalue); + + ret = MIN (r0, r1); + } + else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'd' + || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'c') + { + ret = GS_ALL_DONE; + break; + } + else + /* Fail if we don't know how to handle this tree code. */ + abort (); + + recalculate_side_effects (*expr_p); + break; + } + + /* If we replaced *expr_p, gimplify again. */ + if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr)) + ret = GS_ALL_DONE; + } + while (ret == GS_OK); + + /* If we encountered an error_mark somewhere nested inside, either + stub out the statement or propagate the error back out. */ + if (ret == GS_ERROR) + { + if (is_statement) + *expr_p = build_empty_stmt (); + goto out; + } + +#ifdef ENABLE_CHECKING + /* This was only valid as a return value from the langhook, which + we handled. Make sure it doesn't escape from any other context. */ + if (ret == GS_UNHANDLED) + abort (); +#endif + + if (!*expr_p) + *expr_p = build_empty_stmt (); + if (fallback == fb_none && !is_gimple_stmt (*expr_p)) + { + /* We aren't looking for a value, and we don't have a valid + statement. If it doesn't have side-effects, throw it away. */ + if (!TREE_SIDE_EFFECTS (*expr_p)) + *expr_p = build_empty_stmt (); + else if (!TREE_THIS_VOLATILE (*expr_p)) + /* We only handle volatiles here; anything else with side-effects + must be converted to a valid statement before we get here. */ + abort (); + else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p))) + { + /* Historically, the compiler has treated a bare + reference to a volatile lvalue as forcing a load. */ + tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol"); + *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p); + } + else + /* We can't do anything useful with a volatile reference to + incomplete type, so just throw it away. */ + *expr_p = build_empty_stmt (); + } + + /* If we are gimplifying at the statement level, we're done. Tack + everything together and replace the original statement with the + gimplified form. */ + if (is_statement) + { + append_to_statement_list (*expr_p, &internal_pre); + append_to_statement_list (internal_post, &internal_pre); + annotate_all_with_locus (&internal_pre, input_location); + *expr_p = internal_pre; + goto out; + } + + /* Otherwise we're gimplifying a subexpression, so the resulting value is + interesting. */ + + /* If it's sufficiently simple already, we're done. Unless we are + handling some post-effects internally; if that's the case, we need to + copy into a temp before adding the post-effects to the tree. */ + if (!internal_post && (*gimple_test_f) (*expr_p)) + goto out; + + /* Otherwise, we need to create a new temporary for the gimplified + expression. */ + + /* We can't return an lvalue if we have an internal postqueue. The + object the lvalue refers to would (probably) be modified by the + postqueue; we need to copy the value out first, which means an + rvalue. */ + if ((fallback & fb_lvalue) && !internal_post + && is_gimple_addr_expr_arg (*expr_p)) + { + /* An lvalue will do. Take the address of the expression, store it + in a temporary, and replace the expression with an INDIRECT_REF of + that temporary. */ + tmp = build_addr_expr (*expr_p); + gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue); + *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp); + } + else if ((fallback & fb_rvalue) && is_gimple_rhs (*expr_p)) + { +#if defined ENABLE_CHECKING + if (VOID_TYPE_P (TREE_TYPE (*expr_p))) + abort (); +#endif + + /* An rvalue will do. Assign the gimplified expression into a new + temporary TMP and replace the original expression with TMP. */ + + if (internal_post || (fallback & fb_lvalue)) + /* The postqueue might change the value of the expression between + the initialization and use of the temporary, so we can't use a + formal temp. FIXME do we care? */ + *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p); + else + *expr_p = get_formal_tmp_var (*expr_p, pre_p); + } + else if (fallback & fb_mayfail) + { + /* If this is an asm statement, and the user asked for the impossible, + don't abort. Fail and let gimplify_asm_expr issue an error. */ + ret = GS_ERROR; + goto out; + } + else + { + fprintf (stderr, "gimplification failed:\n"); + print_generic_expr (stderr, *expr_p, 0); + debug_tree (*expr_p); + abort (); + } + +#if defined ENABLE_CHECKING + /* Make sure the temporary matches our predicate. */ + if (!(*gimple_test_f) (*expr_p)) + abort (); +#endif + + if (internal_post) + { + annotate_all_with_locus (&internal_post, input_location); + append_to_statement_list (internal_post, pre_p); + } + + out: + input_location = saved_location; + return ret; +} + +#ifdef ENABLE_CHECKING +/* Compare types A and B for a "close enough" match. */ + +static bool +cpt_same_type (tree a, tree b) +{ + if (lang_hooks.types_compatible_p (a, b)) + return true; + + /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't + link them together. This routine is intended to catch type errors + that will affect the optimizers, and the optimizers don't add new + dereferences of function pointers, so ignore it. */ + if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE) + && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE)) + return true; + + /* ??? The C FE pushes type qualifiers after the fact into the type of + the element from the type of the array. See build_unary_op's handling + of ADDR_EXPR. This seems wrong -- if we were going to do this, we + should have done it when creating the variable in the first place. + Alternately, why aren't the two array types made variants? */ + if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE) + return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b)); + + /* And because of those, we have to recurse down through pointers. */ + if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b)) + return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b)); + + return false; +} + +/* Check for some cases of the front end missing cast expressions. + The type of a dereference should correspond to the pointer type; + similarly the type of an address should match its object. */ + +static tree +check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + tree t = *tp; + tree ptype, otype, dtype; + + switch (TREE_CODE (t)) + { + case INDIRECT_REF: + case ARRAY_REF: + otype = TREE_TYPE (t); + ptype = TREE_TYPE (TREE_OPERAND (t, 0)); + dtype = TREE_TYPE (ptype); + if (!cpt_same_type (otype, dtype)) + abort (); + break; + + case ADDR_EXPR: + ptype = TREE_TYPE (t); + otype = TREE_TYPE (TREE_OPERAND (t, 0)); + dtype = TREE_TYPE (ptype); + if (!cpt_same_type (otype, dtype)) + { + /* &array is allowed to produce a pointer to the element, + rather than a pointer to the array type. */ + if (TREE_CODE (otype) == ARRAY_TYPE + && POINTER_TYPE_P (ptype) + && cpt_same_type (TREE_TYPE (otype), dtype)) + break; + abort (); + } + break; + + default: + return NULL_TREE; + } + + + return NULL_TREE; +} +#endif + +/* Gimplify the body of statements pointed by BODY_P. FNDECL is the + function decl containing BODY. */ + +void +gimplify_body (tree *body_p, tree fndecl) +{ + location_t saved_location = input_location; + tree body; + + timevar_push (TV_TREE_GIMPLIFY); + push_gimplify_context (); + + /* Unshare most shared trees in the body. */ + unshare_all_trees (*body_p); + + /* Make sure input_location isn't set to something wierd. */ + input_location = DECL_SOURCE_LOCATION (fndecl); + + /* Gimplify the function's body. */ + gimplify_stmt (body_p); + body = *body_p; + + /* Unshare again, in case gimplification was sloppy. */ + unshare_all_trees (body); + + /* If there isn't an outer BIND_EXPR, add one. */ + if (TREE_CODE (body) == STATEMENT_LIST) + { + tree t = expr_only (*body_p); + if (t) + body = t; + } + if (TREE_CODE (body) != BIND_EXPR) + { + tree b = build (BIND_EXPR, void_type_node, NULL_TREE, + NULL_TREE, NULL_TREE); + TREE_SIDE_EFFECTS (b) = 1; + append_to_statement_list (body, &BIND_EXPR_BODY (b)); + body = b; + } + *body_p = body; + + pop_gimplify_context (body); + +#ifdef ENABLE_CHECKING + walk_tree (body_p, check_pointer_types_r, NULL, NULL); +#endif + + timevar_pop (TV_TREE_GIMPLIFY); + input_location = saved_location; +} + +/* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL + node for the function we want to gimplify. */ + +void +gimplify_function_tree (tree fndecl) +{ + tree oldfn; + + oldfn = current_function_decl; + current_function_decl = fndecl; + + gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl); + + /* If we're instrumenting function entry/exit, then prepend the call to + the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to + catch the exit hook. */ + /* ??? Add some way to ignore exceptions for this TFE. */ + if (flag_instrument_function_entry_exit + && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl)) + { + tree tf, x, bind; + + tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL); + TREE_SIDE_EFFECTS (tf) = 1; + x = DECL_SAVED_TREE (fndecl); + append_to_statement_list (x, &TREE_OPERAND (tf, 0)); + x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT]; + x = build_function_call_expr (x, NULL); + append_to_statement_list (x, &TREE_OPERAND (tf, 1)); + + bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL); + TREE_SIDE_EFFECTS (bind) = 1; + x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER]; + x = build_function_call_expr (x, NULL); + append_to_statement_list (x, &BIND_EXPR_BODY (bind)); + append_to_statement_list (tf, &BIND_EXPR_BODY (bind)); + + DECL_SAVED_TREE (fndecl) = bind; + } + + current_function_decl = oldfn; +} + +#include "gt-gimplify.h" |