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| author | Marek Polacek <polacek@redhat.com> | 2022-07-05 14:22:26 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2022-07-05 15:15:14 -0400 |
| commit | 543828e79bfa63ef26b11a2c9ea81fd7905f33aa (patch) | |
| tree | dc578a728aeb97650d8846d67f3deb09408b6375 | |
| parent | 1d2aa262482fc9b23201200ca82aa3b8659b072e (diff) | |
| download | gcc-543828e79bfa63ef26b11a2c9ea81fd7905f33aa.zip gcc-543828e79bfa63ef26b11a2c9ea81fd7905f33aa.tar.gz gcc-543828e79bfa63ef26b11a2c9ea81fd7905f33aa.tar.bz2 | |
c-family: Prevent -Wformat warnings with u8 strings [PR105626]
The <https://gcc.gnu.org/pipermail/gcc/2022-May/238679.html> thread
seems to have concluded that -Wformat shouldn't warn about
printf((const char*) u8"test %d\n", 1);
saying "format string is not an array of type 'char'". This code
is not an aliasing violation, and there are no I/O functions for u8
strings, so the const char * cast is OK and shouldn't be disregarded.
PR c++/105626
gcc/c-family/ChangeLog:
* c-format.cc (check_format_arg): Don't emit -Wformat warnings with
u8 strings.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wformat-char8_t-1.C: New test.
| -rw-r--r-- | gcc/c-family/c-format.cc | 3 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/warn/Wformat-char8_t-1.C | 10 |
2 files changed, 12 insertions, 1 deletions
diff --git a/gcc/c-family/c-format.cc b/gcc/c-family/c-format.cc index 4559ca3..7547804 100644 --- a/gcc/c-family/c-format.cc +++ b/gcc/c-family/c-format.cc @@ -1742,7 +1742,8 @@ check_format_arg (void *ctx, tree format_tree, } tree underlying_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))); - if (underlying_type != char_type_node) + if (underlying_type != char_type_node + && !(flag_char8_t && underlying_type == char8_type_node)) { if (underlying_type == char16_type_node || underlying_type == char32_type_node diff --git a/gcc/testsuite/g++.dg/warn/Wformat-char8_t-1.C b/gcc/testsuite/g++.dg/warn/Wformat-char8_t-1.C new file mode 100644 index 0000000..ba6f388 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wformat-char8_t-1.C @@ -0,0 +1,10 @@ +// PR c++/105626 +// { dg-do compile { target c++11 } } +// { dg-options "-Wformat" } +// { dg-additional-options "-fchar8_t" { target c++17_down } } + +int main() +{ + __builtin_printf((const char*) u8"test %d\n", 1); // { dg-bogus "format string" } + return 0; +} |