From a20f6f00bf53a4debcbf361256ed098f8e930850 Mon Sep 17 00:00:00 2001
From: Danny Smith <dannysmith@users.sourceforge.net>
Date: Fri, 1 Apr 2005 08:13:50 +0000
Subject: cygming.h (SUBTARGET_ATTRIBUTE_TABLE): Define, with entry for
 selectany attribute.

	* config/i386/cygming.h (SUBTARGET_ATTRIBUTE_TABLE): Define,
	with entry for selectany attribute.
	* config/i386/i386-protos.h (ix86_handle_selectany_attribute):
	Declare.
	* config/i386/winnt.c (ix86_handle_selectany_attribute): Define.
	(i386_pe_asm_named_section): Handle sections generated by
	selectany attribute.
	* doc/extend.texi (selectany): Document attribute.

From-SVN: r97377
---
 gcc/config/i386/cygming.h     |  4 ++++
 gcc/config/i386/i386-protos.h |  1 +
 gcc/config/i386/winnt.c       | 44 +++++++++++++++++++++++++++++++++++++++----
 3 files changed, 45 insertions(+), 4 deletions(-)

(limited to 'gcc/config')

diff --git a/gcc/config/i386/cygming.h b/gcc/config/i386/cygming.h
index a354994..de731bb 100644
--- a/gcc/config/i386/cygming.h
+++ b/gcc/config/i386/cygming.h
@@ -418,6 +418,10 @@ extern int i386_pe_dllimport_name_p (const char *);
 #undef TARGET_USE_LOCAL_THUNK_ALIAS_P
 #define TARGET_USE_LOCAL_THUNK_ALIAS_P(DECL) (!DECL_ONE_ONLY (DECL))
 
+#define SUBTARGET_ATTRIBUTE_TABLE \
+  /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */ \
+  { "selectany", 0, 0, true, false, false, ix86_handle_selectany_attribute }
+
 #undef TREE
 
 #ifndef BUFSIZ
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index bf69386..1ecc3ae 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -216,6 +216,7 @@ extern int ix86_data_alignment (tree, int);
 extern int ix86_local_alignment (tree, int);
 extern int ix86_constant_alignment (tree, int);
 extern tree ix86_handle_shared_attribute (tree *, tree, tree, int, bool *);
+extern tree ix86_handle_selectany_attribute (tree *, tree, tree, int, bool *); 
 
 extern unsigned int i386_pe_section_type_flags (tree, const char *, int);
 extern void i386_pe_asm_named_section (const char *, unsigned int, tree);
diff --git a/gcc/config/i386/winnt.c b/gcc/config/i386/winnt.c
index c8a7544..ebd8db7 100644
--- a/gcc/config/i386/winnt.c
+++ b/gcc/config/i386/winnt.c
@@ -78,6 +78,36 @@ ix86_handle_shared_attribute (tree *node, tree name,
 
   return NULL_TREE;
 }
+
+/* Handle a "selectany" attribute;
+   arguments as in struct attribute_spec.handler.  */
+tree
+ix86_handle_selectany_attribute (tree *node, tree name,
+			         tree args ATTRIBUTE_UNUSED,
+			         int flags ATTRIBUTE_UNUSED,
+				 bool *no_add_attrs)
+{
+  /* The attribute applies only to objects that are initialized and have
+     external linkage,  */	
+  if (TREE_CODE (*node) == VAR_DECL && TREE_PUBLIC (*node)
+      && (DECL_INITIAL (*node)
+          /* If an object is initialized with a ctor, the static
+	     initialization and destruction code for it is present in
+	     each unit defining the object.  The code that calls the
+	     ctor is protected by a link-once guard variable, so that
+	     the object still has link-once semantics,  */
+    	  || TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (*node))))
+    make_decl_one_only (*node);
+  else
+    {	
+      error ("%qs attribute applies only to initialized variables"
+       	     " with external linkage",  IDENTIFIER_POINTER (name));
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
+
 
 /* Return the type that we should use to determine if DECL is
    imported or exported.  */
@@ -622,7 +652,7 @@ i386_pe_section_type_flags (tree decl, const char *name, int reloc)
 
 void
 i386_pe_asm_named_section (const char *name, unsigned int flags, 
-			   tree decl ATTRIBUTE_UNUSED)
+			   tree decl)
 {
   char flagchars[8], *f = flagchars;
 
@@ -649,10 +679,16 @@ i386_pe_asm_named_section (const char *name, unsigned int flags,
   if (flags & SECTION_LINKONCE)
     {
       /* Functions may have been compiled at various levels of
-         optimization so we can't use `same_size' here.
-         Instead, have the linker pick one.  */
+	 optimization so we can't use `same_size' here.
+	 Instead, have the linker pick one, without warning.
+	 If 'selectany' attibute has been specified,  MS compiler
+	 sets 'discard' characteristic, rather than telling linker
+	 to warn of size or content mismatch, so do the same.  */ 
+      bool discard = (flags & SECTION_CODE)
+		      || lookup_attribute ("selectany",
+					   DECL_ATTRIBUTES (decl));	 
       fprintf (asm_out_file, "\t.linkonce %s\n",
-	       (flags & SECTION_CODE ? "discard" : "same_size"));
+	       (discard  ? "discard" : "same_size"));
     }
 }
 
-- 
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