'locale_t' does not name a type on MinGW

[vedranmiletic]

I'm using 64-bit GCC 7.3.0 shipped by Qt open source on 64-bit Windows 10. I get:

>ninja -j1
[1/51] Building CXX object CMakeFiles/fmt.dir/src/posix.cc.obj                                                          FAILED: CMakeFiles/fmt.dir/src/posix.cc.obj
C:\Qt\Tools\mingw730_64\bin\c++.exe  -DFMT_LOCALE -Iinclude -O3 -DNDEBUG   -std=gnu++11 -MD -MT CMakeFiles/fmt.dir/src/posix.cc.obj -MF CMakeFiles\fmt.dir\src\posix.cc.obj.d -o CMakeFiles/fmt.dir/src/posix.cc.obj -c src/posix.cc
In file included from src/posix.cc:13:0:
include/fmt/posix.h:284:3: error: 'locale_t' does not name a type; did you mean '_locale_t'?
   locale_t locale_;
   ^~~~~~~~
   _locale_t
include/fmt/posix.h:290:16: error: 'locale_t' does not name a type; did you mean '_locale_t'?
   using type = locale_t;
                ^~~~~~~~
                _locale_t
include/fmt/posix.h:297:3: error: 'type' does not name a type; did you mean 'wctype'?
   type get() const { return locale_; }
   ^~~~
   wctype
include/fmt/posix.h: In constructor 'fmt::v5::Locale::Locale()':
include/fmt/posix.h:292:14: error: class 'fmt::v5::Locale' does not have any field named 'locale_'
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
              ^~~~~~~
include/fmt/posix.h:292:32: error: 'LC_NUMERIC_MASK' was not declared in this scope
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
                                ^~~~~~~~~~~~~~~
include/fmt/posix.h:292:32: note: suggested alternative: 'LC_NUMERIC'
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
                                ^~~~~~~~~~~~~~~
                                LC_NUMERIC
include/fmt/posix.h:292:22: error: 'newlocale' was not declared in this scope
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
                      ^~~~~~~~~
include/fmt/posix.h:292:22: note: suggested alternative: 'setlocale'
   Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
                      ^~~~~~~~~
                      setlocale
include/fmt/posix.h:293:10: error: 'locale_' was not declared in this scope
     if (!locale_) FMT_THROW(system_error(errno, "cannot create locale"));
          ^~~~~~~
include/fmt/posix.h:293:10: note: suggested alternative: 'Locale'
     if (!locale_) FMT_THROW(system_error(errno, "cannot create locale"));
          ^~~~~~~
          Locale
include/fmt/posix.h: In destructor 'fmt::v5::Locale::~Locale()':
include/fmt/posix.h:295:26: error: 'locale_' was not declared in this scope
   ~Locale() { freelocale(locale_); }
                          ^~~~~~~
include/fmt/posix.h:295:26: note: suggested alternative: 'Locale'
   ~Locale() { freelocale(locale_); }
                          ^~~~~~~
                          Locale
include/fmt/posix.h:295:15: error: 'freelocale' was not declared in this scope
   ~Locale() { freelocale(locale_); }
               ^~~~~~~~~~
include/fmt/posix.h:295:15: note: suggested alternative: '_free_locale'
   ~Locale() { freelocale(locale_); }
               ^~~~~~~~~~
               _free_locale
include/fmt/posix.h: In member function 'double fmt::v5::Locale::strtod(const char*&) const':
include/fmt/posix.h:303:41: error: 'locale_' was not declared in this scope
     double result = strtod_l(str, &end, locale_);
                                         ^~~~~~~
include/fmt/posix.h:303:41: note: suggested alternative: 'Locale'
     double result = strtod_l(str, &end, locale_);
                                         ^~~~~~~
                                         Locale
include/fmt/posix.h:303:21: error: 'strtod_l' was not declared in this scope
     double result = strtod_l(str, &end, locale_);
                     ^~~~~~~~
include/fmt/posix.h:303:21: note: suggested alternative: '_strtod_l'
     double result = strtod_l(str, &end, locale_);
                     ^~~~~~~~
                     _strtod_l
ninja: build stopped: subcommand failed.

[vitaut]

This was fixed in d5d5865#diff-49942e4b3381e0ffc18f880b3f153b0d. Make sure that the FMT_LOCALE macro is not defined.

[vedranmiletic]

I remembered that one and thought it might be related. Not sure why CMake doesn't configure it correctly, I am not manually specifying anything. Will investigate.

[vedranmiletic]

@vitaut it's wrongly detected, that's why I get -DFMT_LOCALE. It's reproducible even on Linux cross-compiler (I'm using MinGW 64 packaged on Fedora, but presumably Debian-based distros would work too):

$ mingw64-cmake -GNinja .
-- CMake version: 3.14.5                                                                                                            
-- The CXX compiler identification is GNU 8.3.0                                                                                     
-- Check for working CXX compiler: /usr/bin/x86_64-w64-mingw32-g++ 
-- Check for working CXX compiler: /usr/bin/x86_64-w64-mingw32-g++ -- works 
-- Detecting CXX compiler ABI info                                                                                                  
-- Detecting CXX compiler ABI info - done                         
-- Detecting CXX compile features           
-- Detecting CXX compile features - done                                                                                            
-- Version: 5.3.1                                                                                                                   
-- Build type: Release                                            
-- CXX_STANDARD: 11                                                                                                                 
-- Performing Test has_std_11_flag                                
-- Performing Test has_std_11_flag - Success                      
-- Performing Test has_std_0x_flag                                
-- Performing Test has_std_0x_flag - Success                                                                                        
-- Performing Test SUPPORTS_VARIADIC_TEMPLATES                                                                                      
-- Performing Test SUPPORTS_VARIADIC_TEMPLATES - Success          
-- Performing Test SUPPORTS_USER_DEFINED_LITERALS
-- Performing Test SUPPORTS_USER_DEFINED_LITERALS - Success                                                                         
-- Performing Test FMT_HAS_VARIANT     
-- Performing Test FMT_HAS_VARIANT - Success
-- Looking for open        
-- Looking for open - found                                                                                                         
-- Looking for _strtod_l                                                                                                            
-- Looking for _strtod_l - found                                  
-- Looking for C++ include pthread.h                              
-- Looking for C++ include pthread.h - found                                                                                        
-- Looking for pthread_create                                     
-- Looking for pthread_create - found           
-- Found Threads: TRUE                                                                                                              
-- Performing Test HAVE_FNO_DELETE_NULL_POINTER_CHECKS                                                                              
-- Performing Test HAVE_FNO_DELETE_NULL_POINTER_CHECKS - Success
-- FMT_PEDANTIC: OFF                                              
-- Configuring done                                                                                                                 
-- Generating done
CMake Warning:                                                        
  Manually-specified variables were not used by the project:          
                                                                      
    INCLUDE_INSTALL_DIR                                                                                                                      
    SHARE_INSTALL_PREFIX                                                                                                                     
    SYSCONF_INSTALL_DIR                                               
                                                                      
                                                                      
-- Build files have been written to: /home/vedranm/workspace/Development/fmt                                                                 
[vedranm@beg fmt]$ ninja                                              
[1/51] Building CXX object CMakeFiles/fmt.dir/src/posix.cc.obj        
FAILED: CMakeFiles/fmt.dir/src/posix.cc.obj                                                                                                  
/usr/bin/x86_64-w64-mingw32-g++  -DFMT_EXPORT -DFMT_LOCALE -Dfmt_EXPORTS -Iinclude -O2 -DNDEBUG   -std=gnu++11 -MD -MT CMakeFiles/fmt.dir/src/posix.cc.obj -MF CMakeFiles/fmt.dir/src/posix.cc.obj.d -o CMakeFiles/fmt.dir/src/posix.cc.obj -c src/posix.cc
In file included from src/posix.cc:13:                                
include/fmt/posix.h:284:3: error: 'locale_t' does not name a type; did you mean '_locale_t'?                                                 
   locale_t locale_;                                                  
   ^~~~~~~~                                                           
   _locale_t

I'm not very good with CMake macros so I can't provide a patch, but I would be glad to help any other way (e.g. testing).

[vitaut]

Does eac2796 fix the problem?

[vedranmiletic]

It does. I get a different error now for which I will open a separate issue. Thanks!