Re: [lfs-support] Segmentation fault compiling gcc-4.7.2 - Pass 1

[thorsten]

Am 07/08/13 16:56, schrieb Dave Wagler:
> This error occurs while compiling gcc-4.7.2:
> 
>     ../../../gcc-4.7.2/libgcc/libgcc2.c: In function '__multi3':
>     ../../../gcc-4.7.2/libgcc/libgcc2.c:559:1: internal compiler error:
> Segmentation fault

I had segfaults with gcc-4.7.2 due to limited stackspace. gcc-4.7.2 uses
alloca to reserve mem on the stack. You can:

-1-
use ulimit -s to show your stacksize limit and change it with eg.
ulimit -s  20000 to raise the limit

-2-
use the attached patch to change from alloca to xmalloc which will use
the heap instead of the stack

have fun,

thorsten

--- gcc-4.7.2/gcc/ifcvt.c-o     2013-01-16 15:07:24.611752676 +0100
+++ gcc-4.7.2/gcc/ifcvt.c       2013-01-16 15:07:29.379752535 +0100
@@ -2853,8 +2853,10 @@
      register.  */
   max_reg = max_reg_num ();
   size = (max_reg + 1) * sizeof (rtx);
-  then_vals = (rtx *) alloca (size);
-  else_vals = (rtx *) alloca (size);
+  then_vals = (rtx *) xmalloc (size);
+  if ( then_vals == NULL ) return FALSE;
+  else_vals = (rtx *) xmalloc (size);
+  if ( else_vals == NULL ) { free(then_vals); return FALSE; }
   memset (then_vals, 0, size);
   memset (else_vals, 0, size);
 
@@ -2865,6 +2867,8 @@
     {
       VEC_free (int, heap, then_regs);
       VEC_free (int, heap, else_regs);
+      if (then_vals) free (then_vals);
+      if (else_vals) free (else_vals);
       return FALSE;
     }
 
@@ -2890,6 +2894,8 @@
            {
              VEC_free (int, heap, then_regs);
              VEC_free (int, heap, else_regs);
+              if (then_vals) free (then_vals);
+              if (else_vals) free (else_vals);
              return FALSE;
            }
        }
@@ -2908,6 +2914,8 @@
     {
       VEC_free (int, heap, then_regs);
       VEC_free (int, heap, else_regs);
+      if (then_vals) free (then_vals);
+      if (else_vals) free (else_vals);
       return FALSE;
     }
 
@@ -2923,6 +2931,8 @@
       end_sequence ();
       VEC_free (int, heap, then_regs);
       VEC_free (int, heap, else_regs);
+      if (then_vals) free (then_vals);
+      if (else_vals) free (else_vals);
       return FALSE;
     }
   seq = end_ifcvt_sequence (if_info);
@@ -2930,6 +2940,8 @@
     {
       VEC_free (int, heap, then_regs);
       VEC_free (int, heap, else_regs);
+      if (then_vals) free (then_vals);
+      if (else_vals) free (else_vals);
       return FALSE;
     }
 
@@ -2964,10 +2976,11 @@
 
   VEC_free (int, heap, then_regs);
   VEC_free (int, heap, else_regs);
+  if (then_vals) free (then_vals);
+  if (else_vals) free (else_vals);
   return TRUE;
 }
 
-
 /* Determine if a given basic block heads a simple IF-THEN-JOIN or an
    IF-THEN-ELSE-JOIN block.
 

-- 
http://linuxfromscratch.org/mailman/listinfo/lfs-support
FAQ: http://www.linuxfromscratch.org/lfs/faq.html
Unsubscribe: See the above information page