When building a testdir with C++ tests on MSVC 14, I see this error:
source='../../gltests/test-wchar-c++3.cc' object='test-wchar-c++3.obj'
libtool=no \
DEPDIR=.deps depmode=msvc7 /bin/sh ../../build-aux/depcomp \
/home/bruno/msvc/compile cl -nologo -DHAVE_CONFIG_H -DEXEEXT=\".exe\" -I.
-I../../gltests -I.. -DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I.
-I../../gltests -I.. -I../../gltests/.. -I../gllib -I../../gltests/../gllib
-D_WIN32_WINNT=_WIN32_WINNT_WINXP -I/usr/local/msvc64/include -MD -c -o
test-wchar-c++3.obj `cygpath -w '../../gltests/test-wchar-c++3.cc'`
test-wchar-c++3.cc
...
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xlocinfo(127):
error C2440: 'return': cannot convert from 'lconv *' to 'const rpl_lconv *'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xlocinfo(127):
note: Types pointed to are unrelated; conversion requires reinterpret_cast,
C-style cast or function-style cast
...
make[4]: *** [Makefile:9886: test-wchar-c++3.obj] Error 2
The cause is a use of 'struct lconv' deep inside the C++ header files. The fix
is to not override 'struct lconv' and 'localeconv' on this platform. What the
override would do (see lib/localeconv.c lines 53..58) is to map the missing
struct members to those without 'int_' prefix. We can do the same thing through
C macros. This is not as good as the original override, because
- it will also affect other uses of the identifiers int_p_cs_precedes,
int_p_sign_posn, int_p_sep_by_space, int_n_cs_precedes, int_n_sign_posn,
int_n_sep_by_space,
- it will not work in code that uses 'struct lconv' for its own purposes
(other than for localeconv() invocations).
But it should be good enough.
2019-12-11 Bruno Haible <br...@clisp.org>
locale: Fix compilation error in C++ mode on MSVC.
* m4/locale_h.m4 (gl_LOCALE_H): Don't set REPLACE_STRUCT_LCONV on MSVC.
* lib/locale.in.h (int_p_cs_precedes, int_p_sign_posn,
int_p_sep_by_space, int_n_cs_precedes, int_n_sign_posn,
int_n_sep_by_space): Define as macros on MSVC.
diff --git a/m4/locale_h.m4 b/m4/locale_h.m4
index 380e40b..c0ec3fc 100644
--- a/m4/locale_h.m4
+++ b/m4/locale_h.m4
@@ -1,4 +1,4 @@
-# locale_h.m4 serial 22
+# locale_h.m4 serial 23
dnl Copyright (C) 2007, 2009-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -56,7 +56,20 @@ AC_DEFUN([gl_LOCALE_H],
[gl_cv_sys_struct_lconv_ok=no])
])
if test $gl_cv_sys_struct_lconv_ok = no; then
- REPLACE_STRUCT_LCONV=1
+ dnl On native Windows with MSVC, merely define these member names as
macros.
+ dnl This avoids trouble in C++ mode.
+ case "$host_os" in
+ mingw*)
+ AC_EGREP_CPP([Special], [
+#ifdef _MSC_VER
+ Special
+#endif
+ ],
+ [],
+ [REPLACE_STRUCT_LCONV=1])
+ ;;
+ *) REPLACE_STRUCT_LCONV=1 ;;
+ esac
fi
dnl <locale.h> is always overridden, because of GNULIB_POSIXCHECK.
diff --git a/lib/locale.in.h b/lib/locale.in.h
index 918d4dd..77b8b3b 100644
--- a/lib/locale.in.h
+++ b/lib/locale.in.h
@@ -64,6 +64,18 @@
# define LC_MESSAGES 1729
#endif
+/* On native Windows with MSVC, 'struct lconv' lacks the members int_p_* and
+ int_n_*. Instead of overriding 'struct lconv', merely define these member
+ names as macros. This avoids trouble in C++ mode. */
+#if defined _MSC_VER
+# define int_p_cs_precedes p_cs_precedes
+# define int_p_sign_posn p_sign_posn
+# define int_p_sep_by_space p_sep_by_space
+# define int_n_cs_precedes n_cs_precedes
+# define int_n_sign_posn n_sign_posn
+# define int_n_sep_by_space n_sep_by_space
+#endif
+
/* Bionic libc's 'struct lconv' is just a dummy. */
#if @REPLACE_STRUCT_LCONV@
# define lconv rpl_lconv
