[PR libmudflap/53359] don't register symbols not emitted

[Alexandre Oliva <aoliva@redhat.com>]

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libmudflap emits a global initializer that registers memory ranges for
global data symbols.  However, even if IPA decides not to emit a symbol
because it's unused, we'd still emit registration sequences for them in
some cases, which, in the PR testcase, would result in TOC references to
the undefined symbols.

This patch fixes the problem, avoiding registration for symbols that are
not present in the varpool.

Regstrapped on x86_64-linux-gnu and i686-linux-gnu; I've also verified
that it removes the TOC references on a ppc64-linux-gnu cross.

Ok to install?


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don't let mudflap register global symbols that won't be emitted

From: Alexandre Oliva <aoliva@redhat.com>

for  gcc/ChangeLog

	PR libmudflap/53359
	* tree-mudflap.c (mudflap_finish_file): Skip deferred decls
	not found in the symtab.
---

 gcc/tree-mudflap.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)


diff --git a/gcc/tree-mudflap.c b/gcc/tree-mudflap.c
index 90d0448..a9caaf2 100644
--- a/gcc/tree-mudflap.c
+++ b/gcc/tree-mudflap.c
@@ -1335,6 +1335,10 @@ mudflap_finish_file (void)
           if (! TREE_PUBLIC (obj) && ! TREE_ADDRESSABLE (obj))
             continue;
 
+	  /* If we're not emitting the symbol, don't register it.  */
+	  if (!symtab_get_node (obj))
+	    continue;
+
           if (! COMPLETE_TYPE_P (TREE_TYPE (obj)))
             {
               warning (OPT_Wmudflap,

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-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
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Free Software Evangelist      Red Hat Brazil Compiler Engineer