On Thu, 20 Mar 2025, Pali Rohár wrote:
Hello, I started getting new compile warnings during compilation of mingw-w64 runtime.In file included from math/modfl.c:6: .../mingw-w64-headers/crt/fenv.h:64:39: warning: ‘__mingw_fe_dfl_env’ initialized and declared ‘extern’ extern const __MINGW_SELECTANY fenv_t __mingw_fe_dfl_env = { 0, 0 }; ^~~~~~~~~~~~~~~~~~ .../mingw-w64-headers/crt/fenv.h:72:39: warning: ‘__mingw_fe_pc64_env’ initialized and declared ‘extern’ extern const __MINGW_SELECTANY fenv_t __mingw_fe_pc64_env = { 0x3f3f003f, 0 }; ^~~~~~~~~~~~~~~~~~~ .../mingw-w64-headers/crt/fenv.h:76:39: warning: ‘__mingw_fe_pc53_env’ initialized and declared ‘extern’ extern const __MINGW_SELECTANY fenv_t __mingw_fe_pc53_env = { 0x3f3f103f, 0 }; ^~~~~~~~~~~~~~~~~~~
To make this clearer and more actionable, let's repeat a couple relevant bits of context here:
By default, both GCC and Clang ignore and suppress warnings in files in what they consider "system header" directories. When most people build mingw-w64-crt using what would be considered the default way to build it - by installing mingw-w64-headers into the toolchain's system header directory, then building mingw-w64-crt so that it finds those headers implicitly, these warnings are not visible.
Pali builds his mingw-w64-crt in a way that the compiler doesn't consider mingw-w64-headers as system headers, and thus gets warnings that nobody else runs into.
(Not taking any stance on whether any action should be taken on these warnings, just providing context to the situation.)
// Martin _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
