1 files changed, 116 insertions, 0 deletions
diff --git a/tools/build/src/engine/subst.c b/tools/build/src/engine/subst.c
new file mode 100644
index 0000000000..a5fcee08cb
--- /dev/null
+++ b/tools/build/src/engine/subst.c
@@ -0,0 +1,116 @@
+#include "jam.h"
+#include "subst.h"
+
+#include "builtins.h"
+#include "frames.h"
+#include "hash.h"
+#include "lists.h"
+
+#include <stddef.h>
+
+
+typedef struct regex_entry
+{
+    OBJECT * pattern;
+    regexp * regex;
+} regex_entry;
+
+static struct hash * regex_hash;
+
+
+regexp * regex_compile( OBJECT * pattern )
+{
+    int found;
+    regex_entry * e ;
+
+    if ( !regex_hash )
+        regex_hash = hashinit( sizeof( regex_entry ), "regex" );
+
+    e = (regex_entry *)hash_insert( regex_hash, pattern, &found );
+    if ( !found )
+    {
+        e->pattern = object_copy( pattern );
+        e->regex = regcomp( (char *)pattern );
+    }
+
+    return e->regex;
+}
+
+
+LIST * builtin_subst( FRAME * frame, int flags )
+{
+    LIST * result = L0;
+    LIST * const arg1 = lol_get( frame->args, 0 );
+    LISTITER iter = list_begin( arg1 );
+    LISTITER const end = list_end( arg1 );
+
+    if ( iter != end && list_next( iter ) != end && list_next( list_next( iter )
+        ) != end )
+    {
+        char const * const source = object_str( list_item( iter ) );
+        OBJECT * const pattern = list_item( list_next( iter ) );
+        regexp * const repat = regex_compile( pattern );
+
+        if ( regexec( repat, (char *)source) )
+        {
+            LISTITER subst = list_next( iter );
+
+            while ( ( subst = list_next( subst ) ) != end )
+            {
+#define BUFLEN 4096
+                char buf[ BUFLEN + 1 ];
+                char const * in = object_str( list_item( subst ) );
+                char * out = buf;
+
+                for ( ; *in && out < buf + BUFLEN; ++in )
+                {
+                    if ( *in == '\\' || *in == '$' )
+                    {
+                        ++in;
+                        if ( *in == 0 )
+                            break;
+                        if ( *in >= '0' && *in <= '9' )
+                        {
+                            unsigned int const n = *in - '0';
+                            size_t const srclen = repat->endp[ n ] -
+                                repat->startp[ n ];
+                            size_t const remaining = buf + BUFLEN - out;
+                            size_t const len = srclen < remaining
+                                ? srclen
+                                : remaining;
+                            memcpy( out, repat->startp[ n ], len );
+                            out += len;
+                            continue;
+                        }
+                        /* fall through and copy the next character */
+                    }
+                    *out++ = *in;
+                }
+                *out = 0;
+
+                result = list_push_back( result, object_new( buf ) );
+#undef BUFLEN
+            }
+        }
+    }
+
+    return result;
+}
+
+
+static void free_regex( void * xregex, void * data )
+{
+    regex_entry * const regex = (regex_entry *)xregex;
+    object_free( regex->pattern );
+    BJAM_FREE( regex->regex );
+}
+
+
+void regex_done()
+{
+    if ( regex_hash )
+    {
+        hashenumerate( regex_hash, free_regex, (void *)0 );
+        hashdone( regex_hash );
+    }
+}