re PR middle-end/46221 (huge number of c++ testsuite failures, libstdc++.so alias...

2010-11-09  Richard Guenther  <rguenther@suse.de>

	PR middle-end/46221
	* varasm.c (compute_visible_aliases): New function.
	(remove_unreachable_alias_pairs): Aliases make a target available
	even though we reclaimed the cgraph node.
	(finish_aliases_1): Likewise.
	* Makefile.in (varasm.o): Add pointer-set.h dependency.

	* gcc.target/i386/alias-1.c: New testcase.

From-SVN: r166479

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9b543d525aa7af3ee099aa8e1964f15fe1bf7e0a..5c73a47b150cd3ac4b65036c668059557aa32c54 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2010-11-09  Richard Guenther  <rguenther@suse.de>
+
+       PR middle-end/46221
+       * varasm.c (compute_visible_aliases): New function.
+       (remove_unreachable_alias_pairs): Aliases make a target available
+       even though we reclaimed the cgraph node.
+       (finish_aliases_1): Likewise.
+       * Makefile.in (varasm.o): Add pointer-set.h dependency.
+
 2010-11-09  Nick Clifton  <nickc@redhat.com>
 
        * config/mn10300/mn10300-modes.def: New file.

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 459dbeeaceabbb48bb91ab7dbd68c57174f336a3..cc58d7f4c7d1b42daf6de9837e5659c6e5093694 100644 (file)
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -2884,7 +2884,7 @@ varasm.o : varasm.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
    output.h $(TOPLEV_H) $(DIAGNOSTIC_CORE_H) xcoffout.h debug.h $(GGC_H) $(TM_P_H) \
    $(HASHTAB_H) $(TARGET_H) langhooks.h gt-varasm.h $(BASIC_BLOCK_H) \
    $(CFGLAYOUT_H) $(CGRAPH_H) targhooks.h tree-mudflap.h \
-   tree-iterator.h
+   tree-iterator.h pointer-set.h
 function.o : function.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_ERROR_H) \
    $(TREE_H) $(CFGLAYOUT_H) $(GIMPLE_H) $(FLAGS_H) $(FUNCTION_H) $(EXPR_H) \
    $(OPTABS_H) $(LIBFUNCS_H) $(REGS_H) hard-reg-set.h insn-config.h $(RECOG_H) \

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 38bf312deac35efe47bd7e1aa09141a7a6c7fae6..c4fa07999c1d69566e765028351c1b00038f5792 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-09  Richard Guenther  <rguenther@suse.de>
+
+       PR middle-end/46221
+       * gcc.target/i386/alias-1.c: New testcase.
+
 2010-11-08  Jason Merrill  <jason@redhat.com>
 
        * g++.dg/cpp0x/constexpr-sassert.C: New.

diff --git a/gcc/testsuite/gcc.target/i386/alias-1.c b/gcc/testsuite/gcc.target/i386/alias-1.c
new file mode 100644 (file)
index 0000000..adbe2f7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/alias-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+
+int yum;
+void dessert (void) { ++yum; }
+extern void jelly (void) __attribute__ ((alias ("dessert"), weak));
+extern void wobbly (void) __attribute__ ((alias ("jelly"), weak));
+
+/* { dg-final { scan-assembler "wobbly" } } */
+/* { dg-final { scan-assembler "jelly" } } */

diff --git a/gcc/varasm.c b/gcc/varasm.c
index fe60bb2397d3657700f72db10889ad10888d40c4..0c80c931fff5a67779205ce0d637b2d2cbc95fac 100644 (file)
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -53,6 +53,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfglayout.h"
 #include "basic-block.h"
 #include "tree-iterator.h"
+#include "pointer-set.h"
 
 #ifdef XCOFF_DEBUGGING_INFO
 #include "xcoffout.h"          /* Needed for external data
@@ -5415,18 +5416,58 @@ do_assemble_alias (tree decl, tree target)
 }
 
 
+/* Compute the set of indentifier nodes that is generated by aliases
+   whose targets are reachable.  */
+
+static struct pointer_set_t *
+compute_visible_aliases (void)
+{
+  struct pointer_set_t *visible;
+  unsigned i;
+  alias_pair *p;
+  bool changed;
+
+  /* We have to compute the set of visible nodes including aliases
+     themselves.  */
+  visible = pointer_set_create ();
+  do
+    {
+      changed = false;
+      for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); ++i)
+       {
+         struct cgraph_node *fnode = NULL;
+         struct varpool_node *vnode = NULL;
+         fnode = cgraph_node_for_asm (p->target);
+         vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
+         if ((fnode
+              || vnode
+              || pointer_set_contains (visible, p->target))
+             && !pointer_set_insert (visible, DECL_ASSEMBLER_NAME (p->decl)))
+           changed = true;
+       }
+    }
+  while (changed);
+
+  return visible;
+}
+
 /* Remove the alias pairing for functions that are no longer in the call
    graph.  */
 
 void
 remove_unreachable_alias_pairs (void)
 {
+  struct pointer_set_t *visible;
   unsigned i;
   alias_pair *p;
 
   if (alias_pairs == NULL)
     return;
 
+  /* We have to compute the set of visible nodes including aliases
+     themselves.  */
+  visible = compute_visible_aliases ();
+
   for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); )
     {
       if (!DECL_EXTERNAL (p->decl))
@@ -5435,7 +5476,9 @@ remove_unreachable_alias_pairs (void)
          struct varpool_node *vnode = NULL;
          fnode = cgraph_node_for_asm (p->target);
          vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
-         if (fnode == NULL && vnode == NULL)
+         if (!fnode
+             && !vnode
+             && !pointer_set_contains (visible, p->target))
            {
              VEC_unordered_remove (alias_pair, alias_pairs, i);
              continue;
@@ -5444,6 +5487,8 @@ remove_unreachable_alias_pairs (void)
 
       i++;
     }
+
+  pointer_set_destroy (visible);
 }
 
 
@@ -5453,9 +5498,17 @@ remove_unreachable_alias_pairs (void)
 void
 finish_aliases_1 (void)
 {
+  struct pointer_set_t *visible;
   unsigned i;
   alias_pair *p;
 
+  if (alias_pairs == NULL)
+    return;
+
+  /* We have to compute the set of visible nodes including aliases
+     themselves.  */
+  visible = compute_visible_aliases ();
+
   FOR_EACH_VEC_ELT (alias_pair, alias_pairs, i, p)
     {
       tree target_decl;
@@ -5463,6 +5516,9 @@ finish_aliases_1 (void)
       target_decl = find_decl_and_mark_needed (p->decl, p->target);
       if (target_decl == NULL)
        {
+         if (pointer_set_contains (visible, p->target))
+           continue;
+
          if (! (p->emitted_diags & ALIAS_DIAG_TO_UNDEF)
              && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
            {
@@ -5485,6 +5541,8 @@ finish_aliases_1 (void)
          p->emitted_diags |= ALIAS_DIAG_TO_EXTERN;
        }
     }
+
+  pointer_set_destroy (visible);
 }
 
 /* Second pass of completing pending aliases.  Emit the actual assembly.