http://gcc.gnu.org/bugzilla/show_bug.cgi?id=7263
--- Comment #42 from Dodji Seketeli <dodji at gcc dot gnu.org> 2012-05-16 10:51:20 UTC --- Author: dodji Date: Wed May 16 10:51:15 2012 New Revision: 187587 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187587 Log: PR preprocessor/7263 - Avoid pedantic warnings on system headers macro tokens Now that we track token locations accross macro expansions, it would be cool to be able to fix PR preprocessor/7263 for real. That is, consider this example where we have a system header named header.h like this: #define _Complex __complex__ #define _Complex_I 1.0iF and then a normal C file like this: #include "header.h" static _Complex float c = _Complex_I; If we compile the file with -pedantic, the usages of _Complex or _Complex_I should not trigger any warning, even though __complex__ and the complex literal are extensions to the standard C. They shouldn't trigger any warning because _Complex and _Complex_I are defined in a system header (and expanded in normal user code). To be able to handle this, we must address two separate concerns. First, warnings about non-standard usage of numerical literals are emitted directly from within libcpp. So we must teach libcpp's parser for numerical literals to use virtual locations, instead of the spelling location it uses today. Once we have that, as the diagnostics machinery already knows how to avoid emitting errors happening on tokens that come from system headers, we win. Second, there is the issue of tracking locations for declaration specifiers, like the "_Complex" in the declaration: static _Complex float c; For that, we need to arrange for each possible declaration specifier to have its own location, because otherwise, we'd warn on e.g, on: _Complex float c; but not on: static _Complex float c; So this patch addresses the two concerns above. It's actually a follow-up on an earlier patch[1] I wrote as part of my initial work on virtual locations. We then agreed[2] that the second concern was important to address before the patch could get a chance to go in. [1]: http://gcc.gnu.org/ml/gcc-patches/2011-09/msg00957.html [2]: http://gcc.gnu.org/ml/gcc-patches/2011-10/msg00264.html Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk. libcpp/ PR preprocessor/7263 * include/cpplib.h (cpp_classify_number): Take a location parameter. * expr.c (SYNTAX_ERROR_AT, SYNTAX_ERROR2_AT): New diagnostic macros that take a location parameter. (cpp_classify_number): Take a (virtual) location parameter. Use it for diagnostics. Adjust comments. (eval_token): Take a location parameter. Pass it to cpp_classify_number and to diagnostic routines. (_cpp_parse_expr): Use virtual locations of tokens when parsing expressions. Pass a virtual location to eval_token and to diagnostic routines. gcc/c-family/ PR preprocessor/7263 * c-lex.c (c_lex_with_flags): Pass a virtual location to the call to cpp_classify_number. For diagnostics, use the precise location instead of the global input_location. gcc/ PR preprocessor/7263 * c-tree.h (enum c_declspec_word): Declare new enum. (struct c_declspecs::locations): New member. (declspecs_add_qual, declspecs_add_scspec) (declspecs_add_addrspace, declspecs_add_alignas): Take a new location parameter. * c-decl.c (build_null_declspecs): Initialize the new struct c_declspecs::locations member. (declspecs_add_addrspace): Take a location parameter for the address space. Store it onto declaration specifiers. (declspecs_add_qual): Likewise, take a location parameter for the qualifier. (declspecs_add_type): Likewise, take a location parameter for the type specifier. (declspecs_add_scspec): Likewise, take a location parameter for the storage class specifier. (declspecs_add_attrs): Likewise, take a location parameter for the first attribute. (declspecs_add_alignas): Likewise, take a location parameter for the alignas token. (finish_declspecs): For diagnostics, use the location of the relevant declspec, instead of the global input_location. * c-parser.c (c_parser_parameter_declaration): Pass the precise virtual location of the declspec to the declspecs-setters. (c_parser_declspecs): Likewise. Avoid calling c_parser_peek_token repeatedly. gcc/cp/ PR preprocessor/7263 * cp-tree.h (enum cp_decl_spec): Add new enumerators to cover all the possible declarator specifiers so far. (struct cp_decl_specifier_seq::locations): Declare new member. (cp_decl_specifier_seq::{specs, type_location}): Remove. (decl_spec_seq_has_spec_p): Declare new function. * parser.c (cp_parser_check_decl_spec): Remove. (set_and_check_decl_spec_loc): Define new static function. (decl_spec_seq_has_spec_p): Define new public function. (cp_parser_decl_specifier_seq, cp_parser_function_specifier_opt) (cp_parser_type_specifier, cp_parser_simple_type_specifier) (cp_parser_set_storage_class, cp_parser_set_decl_spec_type) (cp_parser_alias_declaration): Set the locations for each declspec, using set_and_check_decl_spec_loc. (cp_parser_explicit_instantiation, cp_parser_init_declarator) (cp_parser_member_declaration, cp_parser_init_declarator): Use the new declspec location for specifiers. Use the new decl_spec_seq_has_spec_p. (cp_parser_type_specifier_seq): Use the new set_and_check_decl_spec_loc. Stop using cp_parser_check_decl_spec. Use the new decl_spec_seq_has_spec_p. (, cp_parser_init_declarator): Use the new set_and_check_decl_spec_loc. (cp_parser_single_declaration, cp_parser_friend_p) (cp_parser_objc_class_ivars, cp_parser_objc_struct_declaration): Use the new decl_spec_seq_has_spec_p. * decl.c (check_tag_decl): Use new decl_spec_seq_has_spec_p. Use the more precise ds_redefined_builtin_type_spec location for diagnostics about re-declaring C++ built-in types. (start_decl, grokvardecl, grokdeclarator): Use the new decl_spec_seq_has_spec_p. gcc/testsuite/ PR preprocessor/7263 * gcc.dg/binary-constants-2.c: Run without tracking locations accross macro expansion. * gcc.dg/binary-constants-3.c: Likewise. * gcc.dg/cpp/sysmac2.c: Likewise. * testsuite/gcc.dg/nofixed-point-2.c: Adjust for more precise location. * gcc.dg/cpp/syshdr3.c: New test. * gcc.dg/cpp/syshdr3.h: New header for the new test above. * gcc.dg/system-binary-constants-1.c: New test. * gcc.dg/system-binary-constants-1.h: New header for the new test above. * g++.dg/cpp/syshdr3.C: New test. * g++.dg/cpp/syshdr3.h: New header the new test above. * g++.dg/system-binary-constants-1.C: New test. * g++.dg/system-binary-constants-1.h: New header the new test above. Added: trunk/gcc/testsuite/g++.dg/cpp/syshdr3.C trunk/gcc/testsuite/g++.dg/cpp/syshdr3.h trunk/gcc/testsuite/g++.dg/system-binary-constants-1.C trunk/gcc/testsuite/g++.dg/system-binary-constants-1.h trunk/gcc/testsuite/gcc.dg/cpp/syshdr3.c trunk/gcc/testsuite/gcc.dg/cpp/syshdr3.h trunk/gcc/testsuite/gcc.dg/system-binary-constants-1.c trunk/gcc/testsuite/gcc.dg/system-binary-constants-1.h Modified: trunk/gcc/ChangeLog trunk/gcc/c-decl.c trunk/gcc/c-family/ChangeLog trunk/gcc/c-family/c-lex.c trunk/gcc/c-parser.c trunk/gcc/c-tree.h trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-tree.h trunk/gcc/cp/decl.c trunk/gcc/cp/decl2.c trunk/gcc/cp/parser.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.dg/binary-constants-2.c trunk/gcc/testsuite/gcc.dg/binary-constants-3.c trunk/gcc/testsuite/gcc.dg/cpp/pr7263-3.c trunk/gcc/testsuite/gcc.dg/cpp/sysmac1.c trunk/gcc/testsuite/gcc.dg/cpp/sysmac2.c trunk/gcc/testsuite/gcc.dg/nofixed-point-2.c trunk/libcpp/ChangeLog trunk/libcpp/expr.c trunk/libcpp/include/cpplib.h
