RIP alloca()

4 files changed, 2 insertions, 521 deletions

diff --git a/configure.ac b/configure.ac
index 1bf0bbf26..3c7714dd7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -682,7 +682,6 @@ AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 
 dnl Checks for library functions.
-AC_FUNC_ALLOCA
 AC_FUNC_VPRINTF
 dnl XXX don't want to re-enable code that's been unused for years at this
 dnl point, but should offer good performance improvements, check after
diff --git a/misc/Makefile.am b/misc/Makefile.am
index 3df16fc8e..b014bf11a 100644
--- a/misc/Makefile.am
+++ b/misc/Makefile.am
@@ -4,7 +4,7 @@ AM_CPPFLAGS = -I$(top_builddir) -I$(top_srcdir) -I$(top_builddir)/include/rpm
 AM_CPPFLAGS += -I$(top_srcdir)/misc
 
 EXTRA_DIST = \
-	alloca.c	basename.c	err.c		err.h \
+	basename.c	err.c		err.h \
 	error.c		error.h \
 	fakefork.c	fnmatch.c	fnmatch.h \
 	getcwd.c	getmntent.c	\
@@ -18,4 +18,4 @@ EXTRA_DIST = \
 noinst_LTLIBRARIES = libmisc.la
 
 libmisc_la_SOURCES =
-libmisc_la_LIBADD = @LTLIBOBJS@ @ALLOCA@
+libmisc_la_LIBADD = @LTLIBOBJS@
diff --git a/misc/alloca.c b/misc/alloca.c
deleted file mode 100644
index 460580638..000000000
--- a/misc/alloca.c
+++ /dev/null
@@ -1,504 +0,0 @@
-/* alloca.c -- allocate automatically reclaimed memory
-   (Mostly) portable public-domain implementation -- D A Gwyn
-
-   This implementation of the PWB library alloca function,
-   which is used to allocate space off the run-time stack so
-   that it is automatically reclaimed upon procedure exit,
-   was inspired by discussions with J. Q. Johnson of Cornell.
-   J.Otto Tennant <jot@cray.com> contributed the Cray support.
-
-   There are some preprocessor constants that can
-   be defined when compiling for your specific system, for
-   improved efficiency; however, the defaults should be okay.
-
-   The general concept of this implementation is to keep
-   track of all alloca-allocated blocks, and reclaim any
-   that are found to be deeper in the stack than the current
-   invocation.  This heuristic does not reclaim storage as
-   soon as it becomes invalid, but it will do so eventually.
-
-   As a special case, alloca(0) reclaims storage without
-   allocating any.  It is a good idea to use alloca(0) in
-   your main control loop, etc. to force garbage collection.  */
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
-#endif
-
-#ifdef emacs
-#include "blockinput.h"
-#endif
-
-/* If compiling with GCC 2, this file's not needed.  */
-#if !defined (__GNUC__) || __GNUC__ < 2
-
-/* If someone has defined alloca as a macro,
-   there must be some other way alloca is supposed to work.  */
-#ifndef alloca
-
-#ifdef emacs
-#ifdef static
-/* actually, only want this if static is defined as ""
-   -- this is for usg, in which emacs must undefine static
-   in order to make unexec workable
-   */
-#ifndef STACK_DIRECTION
-you
-lose
--- must know STACK_DIRECTION at compile-time
-#endif /* STACK_DIRECTION undefined */
-#endif /* static */
-#endif /* emacs */
-
-/* If your stack is a linked list of frames, you have to
-   provide an "address metric" ADDRESS_FUNCTION macro.  */
-
-#if defined (CRAY) && defined (CRAY_STACKSEG_END)
-long i00afunc ();
-#define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg))
-#else
-#define ADDRESS_FUNCTION(arg) &(arg)
-#endif
-
-#if __STDC__
-typedef void *pointer;
-#else
-typedef char *pointer;
-#endif
-
-#ifndef NULL
-#define	NULL	0
-#endif
-
-/* Different portions of Emacs need to call different versions of
-   malloc.  The Emacs executable needs alloca to call xmalloc, because
-   ordinary malloc isn't protected from input signals.  On the other
-   hand, the utilities in lib-src need alloca to call malloc; some of
-   them are very simple, and don't have an xmalloc routine.
-
-   Non-Emacs programs expect this to call xmalloc.
-
-   Callers below should use malloc.  */
-
-#ifndef emacs
-#define malloc xmalloc
-#endif
-extern pointer malloc ();
-
-/* Define STACK_DIRECTION if you know the direction of stack
-   growth for your system; otherwise it will be automatically
-   deduced at run-time.
-
-   STACK_DIRECTION > 0 => grows toward higher addresses
-   STACK_DIRECTION < 0 => grows toward lower addresses
-   STACK_DIRECTION = 0 => direction of growth unknown  */
-
-#ifndef STACK_DIRECTION
-#define	STACK_DIRECTION	0	/* Direction unknown.  */
-#endif
-
-#if STACK_DIRECTION != 0
-
-#define	STACK_DIR	STACK_DIRECTION	/* Known at compile-time.  */
-
-#else /* STACK_DIRECTION == 0; need run-time code.  */
-
-static int stack_dir;		/* 1 or -1 once known.  */
-#define	STACK_DIR	stack_dir
-
-static void
-find_stack_direction ()
-{
-  static char *addr = NULL;	/* Address of first `dummy', once known.  */
-  auto char dummy;		/* To get stack address.  */
-
-  if (addr == NULL)
-    {				/* Initial entry.  */
-      addr = ADDRESS_FUNCTION (dummy);
-
-      find_stack_direction ();	/* Recurse once.  */
-    }
-  else
-    {
-      /* Second entry.  */
-      if (ADDRESS_FUNCTION (dummy) > addr)
-	stack_dir = 1;		/* Stack grew upward.  */
-      else
-	stack_dir = -1;		/* Stack grew downward.  */
-    }
-}
-
-#endif /* STACK_DIRECTION == 0 */
-
-/* An "alloca header" is used to:
-   (a) chain together all alloca'ed blocks;
-   (b) keep track of stack depth.
-
-   It is very important that sizeof(header) agree with malloc
-   alignment chunk size.  The following default should work okay.  */
-
-#ifndef	ALIGN_SIZE
-#define	ALIGN_SIZE	sizeof(double)
-#endif
-
-typedef union hdr
-{
-  char align[ALIGN_SIZE];	/* To force sizeof(header).  */
-  struct
-    {
-      union hdr *next;		/* For chaining headers.  */
-      char *deep;		/* For stack depth measure.  */
-    } h;
-} header;
-
-static header *last_alloca_header = NULL;	/* -> last alloca header.  */
-
-/* Return a pointer to at least SIZE bytes of storage,
-   which will be automatically reclaimed upon exit from
-   the procedure that called alloca.  Originally, this space
-   was supposed to be taken from the current stack frame of the
-   caller, but that method cannot be made to work for some
-   implementations of C, for example under Gould's UTX/32.  */
-
-pointer
-alloca (size)
-     unsigned size;
-{
-  auto char probe;		/* Probes stack depth: */
-  register char *depth = ADDRESS_FUNCTION (probe);
-
-#if STACK_DIRECTION == 0
-  if (STACK_DIR == 0)		/* Unknown growth direction.  */
-    find_stack_direction ();
-#endif
-
-  /* Reclaim garbage, defined as all alloca'd storage that
-     was allocated from deeper in the stack than currently.  */
-
-  {
-    register header *hp;	/* Traverses linked list.  */
-
-#ifdef emacs
-    BLOCK_INPUT;
-#endif
-
-    for (hp = last_alloca_header; hp != NULL;)
-      if ((STACK_DIR > 0 && hp->h.deep > depth)
-	  || (STACK_DIR < 0 && hp->h.deep < depth))
-	{
-	  register header *np = hp->h.next;
-
-	  free ((pointer) hp);	/* Collect garbage.  */
-
-	  hp = np;		/* -> next header.  */
-	}
-      else
-	break;			/* Rest are not deeper.  */
-
-    last_alloca_header = hp;	/* -> last valid storage.  */
-
-#ifdef emacs
-    UNBLOCK_INPUT;
-#endif
-  }
-
-  if (size == 0)
-    return NULL;		/* No allocation required.  */
-
-  /* Allocate combined header + user data storage.  */
-
-  {
-    register pointer new = malloc (sizeof (header) + size);
-    /* Address of header.  */
-
-    if (new == 0)
-      abort();
-
-    ((header *) new)->h.next = last_alloca_header;
-    ((header *) new)->h.deep = depth;
-
-    last_alloca_header = (header *) new;
-
-    /* User storage begins just after header.  */
-
-    return (pointer) ((char *) new + sizeof (header));
-  }
-}
-
-#if defined (CRAY) && defined (CRAY_STACKSEG_END)
-
-#ifdef DEBUG_I00AFUNC
-#include <stdio.h>
-#endif
-
-#ifndef CRAY_STACK
-#define CRAY_STACK
-#ifndef CRAY2
-/* Stack structures for CRAY-1, CRAY X-MP, and CRAY Y-MP */
-struct stack_control_header
-  {
-    long shgrow:32;		/* Number of times stack has grown.  */
-    long shaseg:32;		/* Size of increments to stack.  */
-    long shhwm:32;		/* High water mark of stack.  */
-    long shsize:32;		/* Current size of stack (all segments).  */
-  };
-
-/* The stack segment linkage control information occurs at
-   the high-address end of a stack segment.  (The stack
-   grows from low addresses to high addresses.)  The initial
-   part of the stack segment linkage control information is
-   0200 (octal) words.  This provides for register storage
-   for the routine which overflows the stack.  */
-
-struct stack_segment_linkage
-  {
-    long ss[0200];		/* 0200 overflow words.  */
-    long sssize:32;		/* Number of words in this segment.  */
-    long ssbase:32;		/* Offset to stack base.  */
-    long:32;
-    long sspseg:32;		/* Offset to linkage control of previous
-				   segment of stack.  */
-    long:32;
-    long sstcpt:32;		/* Pointer to task common address block.  */
-    long sscsnm;		/* Private control structure number for
-				   microtasking.  */
-    long ssusr1;		/* Reserved for user.  */
-    long ssusr2;		/* Reserved for user.  */
-    long sstpid;		/* Process ID for pid based multi-tasking.  */
-    long ssgvup;		/* Pointer to multitasking thread giveup.  */
-    long sscray[7];		/* Reserved for Cray Research.  */
-    long ssa0;
-    long ssa1;
-    long ssa2;
-    long ssa3;
-    long ssa4;
-    long ssa5;
-    long ssa6;
-    long ssa7;
-    long sss0;
-    long sss1;
-    long sss2;
-    long sss3;
-    long sss4;
-    long sss5;
-    long sss6;
-    long sss7;
-  };
-
-#else /* CRAY2 */
-/* The following structure defines the vector of words
-   returned by the STKSTAT library routine.  */
-struct stk_stat
-  {
-    long now;			/* Current total stack size.  */
-    long maxc;			/* Amount of contiguous space which would
-				   be required to satisfy the maximum
-				   stack demand to date.  */
-    long high_water;		/* Stack high-water mark.  */
-    long overflows;		/* Number of stack overflow ($STKOFEN) calls.  */
-    long hits;			/* Number of internal buffer hits.  */
-    long extends;		/* Number of block extensions.  */
-    long stko_mallocs;		/* Block allocations by $STKOFEN.  */
-    long underflows;		/* Number of stack underflow calls ($STKRETN).  */
-    long stko_free;		/* Number of deallocations by $STKRETN.  */
-    long stkm_free;		/* Number of deallocations by $STKMRET.  */
-    long segments;		/* Current number of stack segments.  */
-    long maxs;			/* Maximum number of stack segments so far.  */
-    long pad_size;		/* Stack pad size.  */
-    long current_address;	/* Current stack segment address.  */
-    long current_size;		/* Current stack segment size.  This
-				   number is actually corrupted by STKSTAT to
-				   include the fifteen word trailer area.  */
-    long initial_address;	/* Address of initial segment.  */
-    long initial_size;		/* Size of initial segment.  */
-  };
-
-/* The following structure describes the data structure which trails
-   any stack segment.  I think that the description in 'asdef' is
-   out of date.  I only describe the parts that I am sure about.  */
-
-struct stk_trailer
-  {
-    long this_address;		/* Address of this block.  */
-    long this_size;		/* Size of this block (does not include
-				   this trailer).  */
-    long unknown2;
-    long unknown3;
-    long link;			/* Address of trailer block of previous
-				   segment.  */
-    long unknown5;
-    long unknown6;
-    long unknown7;
-    long unknown8;
-    long unknown9;
-    long unknown10;
-    long unknown11;
-    long unknown12;
-    long unknown13;
-    long unknown14;
-  };
-
-#endif /* CRAY2 */
-#endif /* not CRAY_STACK */
-
-#ifdef CRAY2
-/* Determine a "stack measure" for an arbitrary ADDRESS.
-   I doubt that "lint" will like this much.  */
-
-static long
-i00afunc (long *address)
-{
-  struct stk_stat status;
-  struct stk_trailer *trailer;
-  long *block, size;
-  long result = 0;
-
-  /* We want to iterate through all of the segments.  The first
-     step is to get the stack status structure.  We could do this
-     more quickly and more directly, perhaps, by referencing the
-     $LM00 common block, but I know that this works.  */
-
-  STKSTAT (&status);
-
-  /* Set up the iteration.  */
-
-  trailer = (struct stk_trailer *) (status.current_address
-				    + status.current_size
-				    - 15);
-
-  /* There must be at least one stack segment.  Therefore it is
-     a fatal error if "trailer" is null.  */
-
-  if (trailer == 0)
-    abort ();
-
-  /* Discard segments that do not contain our argument address.  */
-
-  while (trailer != 0)
-    {
-      block = (long *) trailer->this_address;
-      size = trailer->this_size;
-      if (block == 0 || size == 0)
-	abort ();
-      trailer = (struct stk_trailer *) trailer->link;
-      if ((block <= address) && (address < (block + size)))
-	break;
-    }
-
-  /* Set the result to the offset in this segment and add the sizes
-     of all predecessor segments.  */
-
-  result = address - block;
-
-  if (trailer == 0)
-    {
-      return result;
-    }
-
-  do
-    {
-      if (trailer->this_size <= 0)
-	abort ();
-      result += trailer->this_size;
-      trailer = (struct stk_trailer *) trailer->link;
-    }
-  while (trailer != 0);
-
-  /* We are done.  Note that if you present a bogus address (one
-     not in any segment), you will get a different number back, formed
-     from subtracting the address of the first block.  This is probably
-     not what you want.  */
-
-  return (result);
-}
-
-#else /* not CRAY2 */
-/* Stack address function for a CRAY-1, CRAY X-MP, or CRAY Y-MP.
-   Determine the number of the cell within the stack,
-   given the address of the cell.  The purpose of this
-   routine is to linearize, in some sense, stack addresses
-   for alloca.  */
-
-static long
-i00afunc (long address)
-{
-  long stkl = 0;
-
-  long size, pseg, this_segment, stack;
-  long result = 0;
-
-  struct stack_segment_linkage *ssptr;
-
-  /* Register B67 contains the address of the end of the
-     current stack segment.  If you (as a subprogram) store
-     your registers on the stack and find that you are past
-     the contents of B67, you have overflowed the segment.
-
-     B67 also points to the stack segment linkage control
-     area, which is what we are really interested in.  */
-
-  stkl = CRAY_STACKSEG_END ();
-  ssptr = (struct stack_segment_linkage *) stkl;
-
-  /* If one subtracts 'size' from the end of the segment,
-     one has the address of the first word of the segment.
-
-     If this is not the first segment, 'pseg' will be
-     nonzero.  */
-
-  pseg = ssptr->sspseg;
-  size = ssptr->sssize;
-
-  this_segment = stkl - size;
-
-  /* It is possible that calling this routine itself caused
-     a stack overflow.  Discard stack segments which do not
-     contain the target address.  */
-
-  while (!(this_segment <= address && address <= stkl))
-    {
-#ifdef DEBUG_I00AFUNC
-      fprintf (stderr, "%011o %011o %011o\n", this_segment, address, stkl);
-#endif
-      if (pseg == 0)
-	break;
-      stkl = stkl - pseg;
-      ssptr = (struct stack_segment_linkage *) stkl;
-      size = ssptr->sssize;
-      pseg = ssptr->sspseg;
-      this_segment = stkl - size;
-    }
-
-  result = address - this_segment;
-
-  /* If you subtract pseg from the current end of the stack,
-     you get the address of the previous stack segment's end.
-     This seems a little convoluted to me, but I'll bet you save
-     a cycle somewhere.  */
-
-  while (pseg != 0)
-    {
-#ifdef DEBUG_I00AFUNC
-      fprintf (stderr, "%011o %011o\n", pseg, size);
-#endif
-      stkl = stkl - pseg;
-      ssptr = (struct stack_segment_linkage *) stkl;
-      size = ssptr->sssize;
-      pseg = ssptr->sspseg;
-      result += size;
-    }
-  return (result);
-}
-
-#endif /* not CRAY2 */
-#endif /* CRAY */
-
-#endif /* no alloca */
-#endif /* not GCC version 2 */
diff --git a/system.h b/system.h
index 573064f4b..bb1e22c65 100644
--- a/system.h
+++ b/system.h
@@ -154,20 +154,6 @@ char *realpath(const char *path, char resolved_path []);
 # endif /* HAVE_NDIR_H */
 #endif /* HAVE_DIRENT_H */
 
-#ifdef __GNUC__
-# undef alloca
-# define alloca __builtin_alloca
-#else
-# ifdef HAVE_ALLOCA_H
-#  include <alloca.h>
-# else
-#  ifndef _AIX
-/* AIX alloca decl has to be the first thing in the file, bletch! */
-char *alloca ();
-#  endif
-# endif
-#endif
-
 #include <ctype.h>
 
 #if HAVE_SYS_MMAN_H