https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43651
Mikhail Maltsev <miyuki at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |miyuki at gcc dot gnu.org --- Comment #6 from Mikhail Maltsev <miyuki at gcc dot gnu.org> --- Clang also emits a warning: $ cat test.c int foo(const char const *data); $ /opt/clang-3.6.2/bin/clang -S -std=c89 test.c test.c:1:20: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] int foo(const char const *data); ^~~~~~ 1 warning generated. $ /opt/clang-3.6.2/bin/clang -S -std=c99 test.c test.c:1:20: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] int foo(const char const *data); ^ 1 warning generated. $ /opt/clang-3.6.2/bin/clang -xc++ -S -std=c++11 test.c test.c:1:20: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] int foo(const char const *data); ^~~~~~ 1 warning generated. "-pedantic-errors" turns this warning into an error in C++ and C89 (but not C99). Recently I came across such problem in the code base, which I work with. In that case it was clearly a mistake, because the author meant 'const char *const data', so it would be nice if GCC could warn about this.