[lto] Unify decl and type registration (issue4515186)

[dnovillo at google dot com (Diego Novillo)]

As discussed in http://gcc.gnu.org/ml/gcc-patches/2011-06/msg00063.html,
this patch moves decl registration in symbol tables to the LTO front
end.  It makes type and symbol registration happen at the same time in
uniquify_nodes.

Tested with LTO profiledbootstrap on x86_64.  Committed to trunk.


Diego.


2011-06-03  Diego Novillo  <dnovillo@google.com>

	* lto-streamer-in.c (get_resolution): Move to lto/lto.c.
	(lto_register_var_decl_in_symtab): Likewise.
	(lto_register_function_decl_in_symtab): Likewise.
	(lto_read_tree): Move VAR_DECL and FUNCTION_DECL registration
	logic to lto_read_decls.

lto/ChangeLog

	* lto.c (get_resolution): Move from lto-streamer-in.c.
	(lto_register_var_decl_in_symtab): Likewise.
	(lto_register_function_decl_in_symtab): Likewise.
	(uniquify_nodes): Call lto_register_var_decl and
	lto_register_function_decl_in_symtab after reading a new
	VAR_DECL or FUNCTION_DECL.

diff --git a/gcc/lto-streamer-in.c b/gcc/lto-streamer-in.c
index 88966f2..a0c5509 100644
--- a/gcc/lto-streamer-in.c
+++ b/gcc/lto-streamer-in.c
@@ -1533,31 +1533,6 @@ lto_input_constructors_and_inits (struct lto_file_decl_data *file_data,
 }
 
 
-/* Return the resolution for the decl with index INDEX from DATA_IN. */
-
-static enum ld_plugin_symbol_resolution
-get_resolution (struct data_in *data_in, unsigned index)
-{
-  if (data_in->globals_resolution)
-    {
-      ld_plugin_symbol_resolution_t ret;
-      /* We can have references to not emitted functions in
-	 DECL_FUNCTION_PERSONALITY at least.  So we can and have
-	 to indeed return LDPR_UNKNOWN in some cases.   */
-      if (VEC_length (ld_plugin_symbol_resolution_t,
-		      data_in->globals_resolution) <= index)
-	return LDPR_UNKNOWN;
-      ret = VEC_index (ld_plugin_symbol_resolution_t,
-		       data_in->globals_resolution,
-		       index);
-      return ret;
-    }
-  else
-    /* Delay resolution finding until decl merging.  */
-    return LDPR_UNKNOWN;
-}
-
-
 /* Unpack all the non-pointer fields of the TS_BASE structure of
    expression EXPR from bitpack BP.  */
 
@@ -2473,117 +2448,6 @@ lto_input_tree_pointers (struct lto_input_block *ib, struct data_in *data_in,
 }
 
 
-/* Register DECL with the global symbol table and change its
-   name if necessary to avoid name clashes for static globals across
-   different files.  */
-
-static void
-lto_register_var_decl_in_symtab (struct data_in *data_in, tree decl)
-{
-  tree context;
-
-  /* Variable has file scope, not local. Need to ensure static variables
-     between different files don't clash unexpectedly.  */
-  if (!TREE_PUBLIC (decl)
-      && !((context = decl_function_context (decl))
-	   && auto_var_in_fn_p (decl, context)))
-    {
-      /* ??? We normally pre-mangle names before we serialize them
-	 out.  Here, in lto1, we do not know the language, and
-	 thus cannot do the mangling again. Instead, we just
-	 append a suffix to the mangled name.  The resulting name,
-	 however, is not a properly-formed mangled name, and will
-	 confuse any attempt to unmangle it.  */
-      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
-      char *label;
-
-      ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
-      SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
-      rest_of_decl_compilation (decl, 1, 0);
-
-      VEC_safe_push (tree, gc, lto_global_var_decls, decl);
-    }
-
-  /* If this variable has already been declared, queue the
-     declaration for merging.  */
-  if (TREE_PUBLIC (decl))
-    {
-      unsigned ix;
-      if (!lto_streamer_cache_lookup (data_in->reader_cache, decl, &ix))
-	gcc_unreachable ();
-      lto_symtab_register_decl (decl, get_resolution (data_in, ix),
-				data_in->file_data);
-    }
-}
-
-
-
-/* Register DECL with the global symbol table and change its
-   name if necessary to avoid name clashes for static globals across
-   different files.  DATA_IN contains descriptors and tables for the
-   file being read.  */
-
-static void
-lto_register_function_decl_in_symtab (struct data_in *data_in, tree decl)
-{
-  /* Need to ensure static entities between different files
-     don't clash unexpectedly.  */
-  if (!TREE_PUBLIC (decl))
-    {
-      /* We must not use the DECL_ASSEMBLER_NAME macro here, as it
-	 may set the assembler name where it was previously empty.  */
-      tree old_assembler_name = decl->decl_with_vis.assembler_name;
-
-      /* FIXME lto: We normally pre-mangle names before we serialize
-	 them out.  Here, in lto1, we do not know the language, and
-	 thus cannot do the mangling again. Instead, we just append a
-	 suffix to the mangled name.  The resulting name, however, is
-	 not a properly-formed mangled name, and will confuse any
-	 attempt to unmangle it.  */
-      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
-      char *label;
-
-      ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
-      SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
-
-      /* We may arrive here with the old assembler name not set
-	 if the function body is not needed, e.g., it has been
-	 inlined away and does not appear in the cgraph.  */
-      if (old_assembler_name)
-	{
-	  tree new_assembler_name = DECL_ASSEMBLER_NAME (decl);
-
-	  /* Make the original assembler name available for later use.
-	     We may have used it to indicate the section within its
-	     object file where the function body may be found.
-	     FIXME lto: Find a better way to maintain the function decl
-	     to body section mapping so we don't need this hack.  */
-	  lto_record_renamed_decl (data_in->file_data,
-				   IDENTIFIER_POINTER (old_assembler_name),
-				   IDENTIFIER_POINTER (new_assembler_name));
-
-	  /* Also register the reverse mapping so that we can find the
-	     new name given to an existing assembler name (used when
-	     restoring alias pairs in input_constructors_or_inits.  */
-	  lto_record_renamed_decl (data_in->file_data,
-				   IDENTIFIER_POINTER (new_assembler_name),
-				   IDENTIFIER_POINTER (old_assembler_name));
-	}
-    }
-
-  /* If this variable has already been declared, queue the
-     declaration for merging.  */
-  if (TREE_PUBLIC (decl) && !DECL_ABSTRACT (decl))
-    {
-      unsigned ix;
-      if (!lto_streamer_cache_lookup (data_in->reader_cache, decl, &ix))
-	gcc_unreachable ();
-      lto_symtab_register_decl (decl, get_resolution (data_in, ix),
-				data_in->file_data);
-    }
-}
-
-
 /* Read an index IX from input block IB and return the tree node at
    DATA_IN->FILE_DATA->GLOBALS_INDEX[IX].  */
 
@@ -2665,11 +2529,6 @@ lto_read_tree (struct lto_input_block *ib, struct data_in *data_in,
   if (TREE_CODE (result) == FUNCTION_DECL)
     gcc_assert (!lto_stream_as_builtin_p (result));
 
-  if (TREE_CODE (result) == VAR_DECL)
-    lto_register_var_decl_in_symtab (data_in, result);
-  else if (TREE_CODE (result) == FUNCTION_DECL && !DECL_BUILT_IN (result))
-    lto_register_function_decl_in_symtab (data_in, result);
-
   /* end_marker = */ lto_input_1_unsigned (ib);
 
 #ifdef LTO_STREAMER_DEBUG
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 9d4e2ed..70d5bde 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -501,6 +501,141 @@ lto_fixup_types (tree t)
     }
 }
 
+
+/* Return the resolution for the decl with index INDEX from DATA_IN. */
+
+static enum ld_plugin_symbol_resolution
+get_resolution (struct data_in *data_in, unsigned index)
+{
+  if (data_in->globals_resolution)
+    {
+      ld_plugin_symbol_resolution_t ret;
+      /* We can have references to not emitted functions in
+	 DECL_FUNCTION_PERSONALITY at least.  So we can and have
+	 to indeed return LDPR_UNKNOWN in some cases.   */
+      if (VEC_length (ld_plugin_symbol_resolution_t,
+		      data_in->globals_resolution) <= index)
+	return LDPR_UNKNOWN;
+      ret = VEC_index (ld_plugin_symbol_resolution_t,
+		       data_in->globals_resolution,
+		       index);
+      return ret;
+    }
+  else
+    /* Delay resolution finding until decl merging.  */
+    return LDPR_UNKNOWN;
+}
+
+
+/* Register DECL with the global symbol table and change its
+   name if necessary to avoid name clashes for static globals across
+   different files.  */
+
+static void
+lto_register_var_decl_in_symtab (struct data_in *data_in, tree decl)
+{
+  tree context;
+
+  /* Variable has file scope, not local. Need to ensure static variables
+     between different files don't clash unexpectedly.  */
+  if (!TREE_PUBLIC (decl)
+      && !((context = decl_function_context (decl))
+	   && auto_var_in_fn_p (decl, context)))
+    {
+      /* ??? We normally pre-mangle names before we serialize them
+	 out.  Here, in lto1, we do not know the language, and
+	 thus cannot do the mangling again. Instead, we just
+	 append a suffix to the mangled name.  The resulting name,
+	 however, is not a properly-formed mangled name, and will
+	 confuse any attempt to unmangle it.  */
+      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+      char *label;
+
+      ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
+      SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
+      rest_of_decl_compilation (decl, 1, 0);
+      VEC_safe_push (tree, gc, lto_global_var_decls, decl);
+    }
+
+  /* If this variable has already been declared, queue the
+     declaration for merging.  */
+  if (TREE_PUBLIC (decl))
+    {
+      unsigned ix;
+      if (!lto_streamer_cache_lookup (data_in->reader_cache, decl, &ix))
+	gcc_unreachable ();
+      lto_symtab_register_decl (decl, get_resolution (data_in, ix),
+				data_in->file_data);
+    }
+}
+
+
+/* Register DECL with the global symbol table and change its
+   name if necessary to avoid name clashes for static globals across
+   different files.  DATA_IN contains descriptors and tables for the
+   file being read.  */
+
+static void
+lto_register_function_decl_in_symtab (struct data_in *data_in, tree decl)
+{
+  /* Need to ensure static entities between different files
+     don't clash unexpectedly.  */
+  if (!TREE_PUBLIC (decl))
+    {
+      /* We must not use the DECL_ASSEMBLER_NAME macro here, as it
+	 may set the assembler name where it was previously empty.  */
+      tree old_assembler_name = decl->decl_with_vis.assembler_name;
+
+      /* FIXME lto: We normally pre-mangle names before we serialize
+	 them out.  Here, in lto1, we do not know the language, and
+	 thus cannot do the mangling again. Instead, we just append a
+	 suffix to the mangled name.  The resulting name, however, is
+	 not a properly-formed mangled name, and will confuse any
+	 attempt to unmangle it.  */
+      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+      char *label;
+
+      ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
+      SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
+
+      /* We may arrive here with the old assembler name not set
+	 if the function body is not needed, e.g., it has been
+	 inlined away and does not appear in the cgraph.  */
+      if (old_assembler_name)
+	{
+	  tree new_assembler_name = DECL_ASSEMBLER_NAME (decl);
+
+	  /* Make the original assembler name available for later use.
+	     We may have used it to indicate the section within its
+	     object file where the function body may be found.
+	     FIXME lto: Find a better way to maintain the function decl
+	     to body section mapping so we don't need this hack.  */
+	  lto_record_renamed_decl (data_in->file_data,
+				   IDENTIFIER_POINTER (old_assembler_name),
+				   IDENTIFIER_POINTER (new_assembler_name));
+
+	  /* Also register the reverse mapping so that we can find the
+	     new name given to an existing assembler name (used when
+	     restoring alias pairs in input_constructors_or_inits.  */
+	  lto_record_renamed_decl (data_in->file_data,
+				   IDENTIFIER_POINTER (new_assembler_name),
+				   IDENTIFIER_POINTER (old_assembler_name));
+	}
+    }
+
+  /* If this variable has already been declared, queue the
+     declaration for merging.  */
+  if (TREE_PUBLIC (decl) && !DECL_ABSTRACT (decl))
+    {
+      unsigned ix;
+      if (!lto_streamer_cache_lookup (data_in->reader_cache, decl, &ix))
+	gcc_unreachable ();
+      lto_symtab_register_decl (decl, get_resolution (data_in, ix),
+				data_in->file_data);
+    }
+}
+
+
 /* Given a streamer cache structure DATA_IN (holding a sequence of trees
    for one compilation unit) go over all trees starting at index FROM until the
    end of the sequence and replace fields of those trees, and the trees
@@ -513,20 +648,25 @@ uniquify_nodes (struct data_in *data_in, unsigned from)
   unsigned len = VEC_length (tree, cache->nodes);
   unsigned i;
 
-  /* Go backwards because childs streamed for the first time come
+  /* Go backwards because children streamed for the first time come
      as part of their parents, and hence are created after them.  */
 
-  /* First register all types in the cache.
+  /* First register all declarations and types in the cache.
      This makes sure to have the original structure in the type cycles
      when registering them and computing hashes.  */
   for (i = len; i-- > from;)
     {
       tree t = VEC_index (tree, cache->nodes, i);
-      if (!t
-	  || !TYPE_P (t))
+
+      if (t == NULL_TREE)
 	continue;
 
-      gimple_register_type (t);
+      if (TREE_CODE (t) == VAR_DECL)
+	lto_register_var_decl_in_symtab (data_in, t);
+      else if (TREE_CODE (t) == FUNCTION_DECL && !DECL_BUILT_IN (t))
+	lto_register_function_decl_in_symtab (data_in, t);
+      else if (TYPE_P (t))
+	gimple_register_type (t);
     }
 
   /* Second fixup all trees in the new cache entries.  */
@@ -665,6 +805,7 @@ uniquify_nodes (struct data_in *data_in, unsigned from)
     }
 }
 
+
 /* Read all the symbols from buffer DATA, using descriptors in DECL_DATA.
    RESOLUTIONS is the set of symbols picked by the linker (read from the
    resolution file when the linker plugin is being used).  */

--
This patch is available for review at http://codereview.appspot.com/4515186