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From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug sanitizer/99801] Address sanitizer false positive with pointer to member function. Date: Mon, 12 Apr 2021 09:29:07 +0000 [thread overview] Message-ID: <bug-99801-4-ZD88ne5Dkh@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-99801-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99801 Martin Liška <marxin at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jason at gcc dot gnu.org --- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> --- So let's consider the following example: $ cat pr99801.C class Curses_table { public: void draw_row() {}; void draw_table(); }; void Curses_table::draw_table() { void (Curses_table::*draw_fn) (void) = &Curses_table::draw_row; auto Curses_table::*draw_fn2 = &Curses_table::draw_row; (this->*draw_fn)(); (this->*draw_fn2)(); } int main() { Curses_table t; t.draw_table(); } What happens is that we wrongly assign DECL_SIZE_UNIT for draw_fn2 in: Breakpoint 5, layout_decl (decl=<var_decl 0x7ffff7fbef30 draw_fn>, known_align=0) at /home/marxin/Programming/gcc/gcc/stor-layout.c:634 (gdb) p debug_tree(type) <offset_type 0x7ffff777d690 type <template_type_parm 0x7ffff777d5e8 auto VOID align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff777d5e8 index 0 level 1 orig_level 1 chain <type_decl 0x7ffff760ee40 auto>> DI size <integer_cst 0x7ffff75e1eb8 type <integer_type 0x7ffff75ff0a8 bitsizetype> constant 64> unit-size <integer_cst 0x7ffff75e1ed0 type <integer_type 0x7ffff75ff000 sizetype> constant 8> align:64 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff777d690 basetype <record_type 0x7ffff777d888 Curses_table>> while draw_fn is called with: (gdb) p debug_tree(type) <record_type 0x7ffff777d3f0 type_2 TI size <integer_cst 0x7ffff75e1f00 type <integer_type 0x7ffff75ff0a8 bitsizetype> constant 128> unit-size <integer_cst 0x7ffff75e1f18 type <integer_type 0x7ffff75ff000 sizetype> constant 16> align:64 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff777d498 fields <field_decl 0x7ffff760eab0 __pfn type <pointer_type 0x7ffff777d2a0 type <method_type 0x7ffff777d0a8> unsigned DI size <integer_cst 0x7ffff75e1eb8 constant 64> unit-size <integer_cst 0x7ffff75e1ed0 constant 8> align:64 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x7ffff777d348> unsigned nonaddressable DI /home/marxin/Programming/testcases/pr99801.C:9:38 size <integer_cst 0x7ffff75e1eb8 64> unit-size <integer_cst 0x7ffff75e1ed0 8> align:64 warn_if_not_align:0 offset_align 128 offset <integer_cst 0x7ffff75e1ee8 constant 0> bit-offset <integer_cst 0x7ffff75e1f30 constant 0> context <record_type 0x7ffff777d3f0> chain <field_decl 0x7ffff760eb48 __delta type <integer_type 0x7ffff75ff738 long int> nonaddressable DI /home/marxin/Programming/testcases/pr99801.C:9:38 size <integer_cst 0x7ffff75e1eb8 64> unit-size <integer_cst 0x7ffff75e1ed0 8> align:64 warn_if_not_align:0 offset_align 128 offset <integer_cst 0x7ffff75e1ee8 0> bit-offset <integer_cst 0x7ffff75e1eb8 64> context <record_type 0x7ffff777d3f0>>> ptrmemfunc fn type <pointer_type 0x7ffff777d2a0> chain <type_decl 0x7ffff760ebe0 __ptrmemfunc_type>> later then the corresponding record_type is set as TREE_TYPE of draw_fn2: (gdb) bt #0 0x0000000000a16cd0 in cp_finish_decl (decl=decl@entry=<var_decl 0x7ffff7794510 draw_fn2>, init=<optimized out>, init@entry=<ptrmem_cst 0x7ffff7774b20>, init_const_expr_p=true, asmspec_tree=<optimized out>, asmspec_tree@entry=<tree 0x0>, flags=5) at /home/marxin/Programming/gcc/gcc/cp/decl.c:7744 #1 0x0000000000b06168 in cp_parser_init_declarator (parser=0x7ffff760e7b8, flags=<optimized out>, decl_specifiers=0x7fffffffd2b0, checks=0x0, function_definition_allowed_p=<optimized out>, member_p=<optimized out>, declares_class_or_enum=0, function_definition_p=0x7fffffffd350, maybe_range_for_decl=0x0, init_loc=0x7fffffffd29c, auto_result=0x7fffffffd3f0) at /home/marxin/Programming/gcc/gcc/cp/parser.c:21872 #2 0x0000000000ae166d in cp_parser_simple_declaration (parser=0x7ffff760e7b8, function_definition_allowed_p=<optimized out>, maybe_range_for_decl=0x0) at /home/marxin/Programming/gcc/gcc/cp/parser.c:14442 #3 0x0000000000ae385b in cp_parser_declaration_statement (parser=parser@entry=0x7ffff760e7b8) at /home/marxin/Programming/gcc/gcc/cp/parser.c:13577 #4 0x0000000000ae3ea4 in cp_parser_statement (parser=0x7ffff760e7b8, in_statement_expr=<tree 0x0>, in_compound=<optimized out>, if_p=<optimized out>, chain=<optimized out>, loc_after_labels=0x0) at /home/marxin/Programming/gcc/gcc/cp/parser.c:11808 #5 0x0000000000ae5983 in cp_parser_statement_seq_opt (parser=parser@entry=0x7ffff760e7b8, in_statement_expr=in_statement_expr@entry=<tree 0x0>) at /home/marxin/Programming/gcc/gcc/cp/parser.c:12174 but the DECL_SIZE_UNIT is not adjusted. @Jason: Can you please take a look?
next prev parent reply other threads:[~2021-04-12 9:29 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-28 16:07 [Bug c++/99801] New: " fsb4000 at yandex dot ru 2021-03-30 7:32 ` [Bug sanitizer/99801] " marxin at gcc dot gnu.org 2021-04-12 9:29 ` marxin at gcc dot gnu.org [this message] 2021-08-16 11:41 ` [Bug c++/99801] " marxin at gcc dot gnu.org 2021-08-16 11:41 ` marxin at gcc dot gnu.org 2021-11-05 16:26 ` marxin at gcc dot gnu.org 2022-12-25 6:52 ` pinskia at gcc dot gnu.org 2022-12-25 6:56 ` pinskia at gcc dot gnu.org
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