[Bug fortran/48066] [4.3/4.4/4.5/4.6 Regression] Segfault with SUM of zero-sized array

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48066

--- Comment #9 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2011-03-12 
17:22:50 UTC ---
This one looks better:

Index: m4/ifunction_logical.m4                      
===================================================================
--- m4/ifunction_logical.m4     (Revision 170897)                  
+++ m4/ifunction_logical.m4     (Arbeitskopie)                     
@@ -149,7 +149,7 @@                                                

   dest = retarray->data;                                          

-  continue_loop = 1;                                              
+  continue_loop = len > 0;                                        
   while (continue_loop)                                           
     {                                                             
       const GFC_LOGICAL_1 * restrict src;                         
@@ -158,17 +158,12 @@                                              
       {                                                           
 ')dnl                                                             
 define(START_ARRAY_BLOCK,                                         
-`        if (len <= 0)                                            
-         *dest = '$1`;                                            
-       else                                                       
+`      for (n = 0; n < len; n++, src += delta)                    
          {                                                        
-           for (n = 0; n < len; n++, src += delta)                
-             {                                                    
 ')dnl                                                             
 define(FINISH_ARRAY_FUNCTION,                                     
-    `          }                                                  
-           *dest = result;                                        
-         }                                                        
+`        }                                                        
+       *dest = result;                                            
       }                                                           
       /* Advance to the next element.  */                         
       count[0]++;                                                 
Index: m4/ifunction.m4
===================================================================
--- m4/ifunction.m4     (Revision 170897)
+++ m4/ifunction.m4     (Arbeitskopie)
@@ -122,7 +122,7 @@
   base = array->data;
   dest = retarray->data;

-  continue_loop = 1;
+  continue_loop = len > 0;
   while (continue_loop)
     {
       const atype_name * restrict src;
@@ -131,18 +131,13 @@
       {
 ')dnl
 define(START_ARRAY_BLOCK,
-`      if (len <= 0)
-         *dest = '$1`;
-       else
+`      for (n = 0; n < len; n++, src += delta)
          {
-           for (n = 0; n < len; n++, src += delta)
-             {
 ')dnl
 define(FINISH_ARRAY_FUNCTION,
-`            }
-           '$1`
-           *dest = result;
-         }
+`        }
+       '$1`
+       *dest = result;
       }
       /* Advance to the next element.  */
       count[0]++;

Let's see if it survives regression-testing.