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| author | Jason Merrill <jason@redhat.com> | 2022-06-10 15:26:36 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2022-06-13 17:54:37 -0400 |
| commit | 2c11662391bafd74c9d19bf7626b7bcef41c1323 (patch) | |
| tree | 0b5b728822afbb9790590368d1decd1c12edef6f | |
| parent | 72b185189f914a412ae39776cd284dfaeaf2213b (diff) | |
| download | gcc-2c11662391bafd74c9d19bf7626b7bcef41c1323.zip gcc-2c11662391bafd74c9d19bf7626b7bcef41c1323.tar.gz gcc-2c11662391bafd74c9d19bf7626b7bcef41c1323.tar.bz2 | |
ubsan: -Wreturn-type and ubsan trap-on-error
I noticed that -fsanitize=undefined -fsanitize-undefined-trap-on-error was
omitting the usual -Wreturn-type warning for control flowing off the end of
a function. This was because the warning code was looking for calls either
to __builtin_unreachable or the UBSan function, but these flags produce a
call to __builtin_trap instead.
gcc/c-family/ChangeLog:
* c-ubsan.cc (ubsan_instrument_return): Use BUILTINS_LOCATION.
gcc/ChangeLog:
* tree-cfg.cc (pass_warn_function_return::execute): Also check
BUILT_IN_TRAP.
gcc/testsuite/ChangeLog:
* g++.dg/ubsan/return-8.C: New test.
| -rw-r--r-- | gcc/c-family/c-ubsan.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/ubsan/return-8.C | 9 | ||||
| -rw-r--r-- | gcc/tree-cfg.cc | 5 |
3 files changed, 15 insertions, 3 deletions
diff --git a/gcc/c-family/c-ubsan.cc b/gcc/c-family/c-ubsan.cc index 48f9487..a2cd8fb 100644 --- a/gcc/c-family/c-ubsan.cc +++ b/gcc/c-family/c-ubsan.cc @@ -308,7 +308,9 @@ tree ubsan_instrument_return (location_t loc) { if (flag_sanitize_undefined_trap_on_error) - return build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_TRAP), 0); + return build_call_expr_loc + /* pass_warn_function_return checks for BUILTINS_LOCATION. */ + (BUILTINS_LOCATION, builtin_decl_explicit (BUILT_IN_TRAP), 0); tree data = ubsan_create_data ("__ubsan_missing_return_data", 1, &loc, NULL_TREE, NULL_TREE); diff --git a/gcc/testsuite/g++.dg/ubsan/return-8.C b/gcc/testsuite/g++.dg/ubsan/return-8.C new file mode 100644 index 0000000..354c960 --- /dev/null +++ b/gcc/testsuite/g++.dg/ubsan/return-8.C @@ -0,0 +1,9 @@ +// { dg-additional-options "-fsanitize=undefined -fsanitize-undefined-trap-on-error" } + +bool b; + +int f() { + if (b) return 42; +} // { dg-warning "-Wreturn-type" } + +int main() { f(); } diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc index 9e5d84a..c67c278 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -9543,7 +9543,7 @@ pass_warn_function_return::execute (function *fun) } /* The C++ FE turns fallthrough from the end of non-void function into __builtin_unreachable () call with BUILTINS_LOCATION. - Recognize those too. */ + Recognize those as well as calls from ubsan_instrument_return. */ basic_block bb; if (!warning_suppressed_p (fun->decl, OPT_Wreturn_type)) FOR_EACH_BB_FN (bb, fun) @@ -9555,7 +9555,8 @@ pass_warn_function_return::execute (function *fun) if (last && ((LOCATION_LOCUS (gimple_location (last)) == BUILTINS_LOCATION - && gimple_call_builtin_p (last, BUILT_IN_UNREACHABLE)) + && (gimple_call_builtin_p (last, BUILT_IN_UNREACHABLE) + || gimple_call_builtin_p (last, BUILT_IN_TRAP))) || gimple_call_builtin_p (last, ubsan_missing_ret))) { gimple_stmt_iterator gsi = gsi_for_stmt (last); |