diff options
Diffstat (limited to 'gcc/lto/lto.c')
-rw-r--r-- | gcc/lto/lto.c | 151 |
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). */ |