[gentoo-commits] gentoo commit in src/patchsets/windowmaker/0.92.0: WindowMaker-0.92.0-alt-alloca.patch

[Fabian Groffen (grobian)]

grobian     10/12/01 17:49:47

  Added:                WindowMaker-0.92.0-alt-alloca.patch
  Log:
  windowmaker-0.92.0-patchset-4

Revision  Changes    Path
1.1                  src/patchsets/windowmaker/0.92.0/WindowMaker-0.92.0-alt-alloca.patch

file : http://sources.gentoo.org/viewvc.cgi/gentoo/src/patchsets/windowmaker/0.92.0/WindowMaker-0.92.0-alt-alloca.patch?rev=1.1&view=markup
plain: http://sources.gentoo.org/viewvc.cgi/gentoo/src/patchsets/windowmaker/0.92.0/WindowMaker-0.92.0-alt-alloca.patch?rev=1.1&content-type=text/plain

Index: WindowMaker-0.92.0-alt-alloca.patch
===================================================================
 configure.ac       |    1 -
 wrlib/Makefile.am  |    2 +-
 wrlib/alloca.c     |  504 ----------------------------------------------------
 wrlib/configure.in |    1 -
 wrlib/nxpm.c       |  171 ++++++++++++------
 wrlib/png.c        |   39 +---
 6 files changed, 128 insertions(+), 590 deletions(-)

diff --git a/configure.ac b/configure.ac
index b49cad5..1c7c4dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -85,7 +85,6 @@ dnl ============================
 dnl not used anywhere
 dnl AC_FUNC_MEMCMP  
 AC_FUNC_VPRINTF
-AC_FUNC_ALLOCA
 AC_CHECK_FUNCS(gethostname select poll strerror strcasecmp strncasecmp \
 	       setsid atexit mallinfo mkstemp snprintf vsnprintf asprintf \
 	       vasprintf)
diff --git a/wrlib/Makefile.am b/wrlib/Makefile.am
index f7a3428..659d40c 100644
--- a/wrlib/Makefile.am
+++ b/wrlib/Makefile.am
@@ -56,7 +56,7 @@ x86_specific.o: x86_specific.c
 
 INCLUDES = $(DFLAGS) @HEADER_SEARCH_PATH@
 
-libwraster_la_LIBADD = @ALLOCA@ @LIBRARY_SEARCH_PATH@ @GFXLIBS@ @XLIBS@ -lm
+libwraster_la_LIBADD = @LIBRARY_SEARCH_PATH@ @GFXLIBS@ @XLIBS@ -lm
 
 DISTCLEANFILES = wrlib.pc
 
diff --git a/wrlib/alloca.c b/wrlib/alloca.c
deleted file mode 100644
index 7598aea..0000000
--- a/wrlib/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@××××.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 use 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/wrlib/configure.in b/wrlib/configure.in
index a1ecd05..471d9a3 100644
--- a/wrlib/configure.in
+++ b/wrlib/configure.in
@@ -20,7 +20,6 @@ dnl Checks for library functions.
 dnl ============================
 AC_PROG_GCC_TRADITIONAL
 AC_FUNC_MEMCMP
-AC_FUNC_ALLOCA
 AC_TYPE_SIGNAL
 AC_FUNC_VPRINTF
 
diff --git a/wrlib/nxpm.c b/wrlib/nxpm.c
index 33b8806..639dd9c 100644
--- a/wrlib/nxpm.c
+++ b/wrlib/nxpm.c
@@ -21,24 +21,6 @@
 
 #include <config.h>
 
-/* AIX requires this to be the first thing in the file.  */
-#ifdef __GNUC__
-# define alloca __builtin_alloca
-#else
-# if HAVE_ALLOCA_H
-#  include <alloca.h>
-# else
-#  ifdef _AIX
-#   pragma alloca
-#  else
-#   ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-#   endif
-#  endif
-# endif
-#endif
-
-
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -76,8 +58,8 @@ RImage*
 RGetImageFromXPMData(RContext *context, char **data)
 {
     RImage *image = NULL;
-    unsigned char *color_table[4];
-    unsigned short *symbol_table;
+    unsigned char *color_table[4] = {NULL, NULL, NULL, NULL};
+    unsigned short *symbol_table = NULL;
     unsigned char *r, *g, *b, *a;
     int i, j, k, line = 0;
     int transp;
@@ -92,18 +74,27 @@ RGetImageFromXPMData(RContext *context, char **data)
     if (csize!=1 && csize!=2)
         goto bad_format;
 
-    color_table[0] = alloca(ccount);
-    color_table[1] = alloca(ccount);
-    color_table[2] = alloca(ccount);
-    color_table[3] = alloca(ccount);
-    symbol_table = alloca(ccount * sizeof(unsigned short));
+    color_table[0] = malloc(ccount);
+    color_table[1] = malloc(ccount);
+    color_table[2] = malloc(ccount);
+    color_table[3] = malloc(ccount);
+    symbol_table = malloc(ccount * sizeof(unsigned short));
 
     bsize = csize * w + 16;
 
     if (!color_table[0] || !color_table[1] || !color_table[2] ||
         !color_table[3] || !symbol_table || !bsize) {
         RErrorCode = RERR_NOMEMORY;
-        alloca(0);
+		if (color_table[0])
+			free(color_table[0]);
+		if (color_table[1])
+			free(color_table[1]);
+		if (color_table[2])
+			free(color_table[2]);
+		if (color_table[3])
+			free(color_table[3]);
+		if (symbol_table)
+			free(symbol_table);
         return NULL;
     }
 
@@ -152,7 +143,16 @@ RGetImageFromXPMData(RContext *context, char **data)
 
     image = RCreateImage(w, h, transp);
     if (!image) {
-        alloca(0);
+		if (color_table[0])
+			free(color_table[0]);
+		if (color_table[1])
+			free(color_table[1]);
+		if (color_table[2])
+			free(color_table[2]);
+		if (color_table[3])
+			free(color_table[3]);
+		if (symbol_table)
+			free(symbol_table);
         return NULL;
     }
 
@@ -212,16 +212,30 @@ RGetImageFromXPMData(RContext *context, char **data)
         line++;
     }
 
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+	if (color_table[0])
+		free(color_table[0]);
+	if (color_table[1])
+		free(color_table[1]);
+	if (color_table[2])
+		free(color_table[2]);
+	if (color_table[3])
+		free(color_table[3]);
+	if (symbol_table)
+		free(symbol_table);
     return image;
 
 bad_format:
     RErrorCode = RERR_BADIMAGEFILE;
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+	if (color_table[0])
+		free(color_table[0]);
+	if (color_table[1])
+		free(color_table[1]);
+	if (color_table[2])
+		free(color_table[2]);
+	if (color_table[3])
+		free(color_table[3]);
+	if (symbol_table)
+		free(symbol_table);
     if (image)
         RReleaseImage(image);
     return NULL;
@@ -234,9 +248,9 @@ RLoadXPM(RContext *context, char *file, int index)
 {
     RImage *image = NULL;
     char line[LINEWIDTH+1];
-    char *buffer;
-    unsigned char *color_table[4];
-    unsigned short *symbol_table;
+    char *buffer = NULL;
+    unsigned char *color_table[4] = {NULL, NULL, NULL, NULL};
+    unsigned short *symbol_table = NULL;
     unsigned char *r, *g, *b, *a;
     int i, j, k;
     int transp;
@@ -272,20 +286,31 @@ RLoadXPM(RContext *context, char *file, int index)
     if (csize!=1 && csize!=2)
         goto bad_format;
 
-    color_table[0] = alloca(ccount);
-    color_table[1] = alloca(ccount);
-    color_table[2] = alloca(ccount);
-    color_table[3] = alloca(ccount);
-    symbol_table = alloca(ccount * sizeof(unsigned short));
+    color_table[0] = malloc(ccount);
+    color_table[1] = malloc(ccount);
+    color_table[2] = malloc(ccount);
+    color_table[3] = malloc(ccount);
+    symbol_table = malloc(ccount * sizeof(unsigned short));
 
     bsize = csize * w + 16;
-    buffer = alloca(bsize);
+    buffer = malloc(bsize);
 
     if (!color_table[0] || !color_table[1] || !color_table[2] ||
-        !color_table[3] || !symbol_table || !bsize) {
+        !color_table[3] || !symbol_table || !bsize || !buffer) {
         RErrorCode = RERR_NOMEMORY;
         fclose(f);
-        alloca(0);
+		if (color_table[0])
+			free(color_table[0]);
+		if (color_table[1])
+			free(color_table[1]);
+		if (color_table[2])
+			free(color_table[2]);
+		if (color_table[3])
+			free(color_table[3]);
+		if (symbol_table)
+			free(symbol_table);
+		if (buffer)
+			free(buffer);
         return NULL;
     }
 
@@ -339,7 +364,18 @@ RLoadXPM(RContext *context, char *file, int index)
     image = RCreateImage(w, h, transp);
     if (!image) {
         fclose(f);
-        alloca(0);
+		if (color_table[0])
+			free(color_table[0]);
+		if (color_table[1])
+			free(color_table[1]);
+		if (color_table[2])
+			free(color_table[2]);
+		if (color_table[3])
+			free(color_table[3]);
+		if (symbol_table)
+			free(symbol_table);
+		if (buffer)
+			free(buffer);
         return NULL;
     }
 
@@ -406,17 +442,35 @@ RLoadXPM(RContext *context, char *file, int index)
     }
 
     fclose(f);
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+	if (color_table[0])
+		free(color_table[0]);
+	if (color_table[1])
+		free(color_table[1]);
+	if (color_table[2])
+		free(color_table[2]);
+	if (color_table[3])
+		free(color_table[3]);
+	if (symbol_table)
+		free(symbol_table);
+	if (buffer)
+		free(buffer);
     return image;
 
 bad_format:
     RErrorCode = RERR_BADIMAGEFILE;
     fclose(f);
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+	if (color_table[0])
+		free(color_table[0]);
+	if (color_table[1])
+		free(color_table[1]);
+	if (color_table[2])
+		free(color_table[2]);
+	if (color_table[3])
+		free(color_table[3]);
+	if (symbol_table)
+		free(symbol_table);
+	if (buffer)
+		free(buffer);
     if (image)
         RReleaseImage(image);
     return NULL;
@@ -424,9 +478,18 @@ bad_format:
 bad_file:
     RErrorCode = RERR_BADIMAGEFILE;
     fclose(f);
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+	if (color_table[0])
+		free(color_table[0]);
+	if (color_table[1])
+		free(color_table[1]);
+	if (color_table[2])
+		free(color_table[2]);
+	if (color_table[3])
+		free(color_table[3]);
+	if (symbol_table)
+		free(symbol_table);
+	if (buffer)
+		free(buffer);
     if (image)
         RReleaseImage(image);
     return NULL;
diff --git a/wrlib/png.c b/wrlib/png.c
index ee04a1c..b79060e 100644
--- a/wrlib/png.c
+++ b/wrlib/png.c
@@ -21,24 +21,6 @@
 
 #include <config.h>
 
-/* AIX requires this to be the first thing in the file.  */
-#ifdef __GNUC__
-# define alloca __builtin_alloca
-#else
-# if HAVE_ALLOCA_H
-#  include <alloca.h>
-# else
-#  ifdef _AIX
-#   pragma alloca
-#  else
-#   ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-#   endif
-#  endif
-# endif
-#endif
-
-
 #ifdef USE_PNG
 
 #include <stdlib.h>
@@ -182,27 +164,25 @@ RLoadPNG(RContext *context, char *file, int index)
         image->background.blue = bkcolor->blue >> 8;
     }
 
-    png_rows = alloca(sizeof(char*)*height);
+    png_rows = calloc(height, sizeof(char*));
     if (!png_rows) {
         RErrorCode = RERR_NOMEMORY;
         fclose(f);
         RReleaseImage(image);
         png_destroy_read_struct(&png, &pinfo, &einfo);
-#ifdef C_ALLOCA
-        alloca(0);
-#endif
         return NULL;
     }
     for (y=0; y<height; y++) {
-        png_rows[y] = alloca(png_get_rowbytes(png, pinfo));
+        png_rows[y] = malloc(png_get_rowbytes(png, pinfo));
         if (!png_rows[y]) {
             RErrorCode = RERR_NOMEMORY;
             fclose(f);
             RReleaseImage(image);
             png_destroy_read_struct(&png, &pinfo, &einfo);
-#ifdef C_ALLOCA
-            alloca(0);
-#endif
+			while (y-- > 0)
+				if (png_rows[y])
+					free(png_rows[y]);
+			free(png_rows);
             return NULL;
         }
     }
@@ -231,9 +211,10 @@ RLoadPNG(RContext *context, char *file, int index)
             }
         }
     }
-#ifdef C_ALLOCA
-    alloca(0);
-#endif
+    for (y=0; y<height; y++)
+		if (png_rows[y])
+			free(png_rows[y]);
+	free(png_rows);
     return image;
 }