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-rw-r--r--gcc/lto/lto.c151
1 files changed, 146 insertions, 5 deletions
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). */