Merge branch 'clang-cl-improvements' into 'master'

Some improvements to clang-cl builds

Closes #2338 and #2357

See merge request GNOME/glib!2004

docs/reference/glib/glib-sections.txt

@@ -753,6 +753,7 @@ glib_typeof_2_68
 g_macro__has_attribute
 g_macro__has_builtin
 g_macro__has_feature
+g_macro__has_extension
 </SECTION>
 
 <SECTION>

glib/gmacros.h

@@ -276,6 +276,12 @@
 #define g_macro__has_builtin(x) 0
 #endif
 
+#ifdef __has_extension
+#define g_macro__has_extension __has_extension
+#else
+#define g_macro__has_extension(x) 0
+#endif
+
 /**
  * G_GNUC_ALLOC_SIZE:
  * @x: the index of the argument specifying the allocation size
@@ -754,7 +760,8 @@
 #ifndef __GI_SCANNER__ /* The static assert macro really confuses the introspection parser */
 #define G_PASTE_ARGS(identifier1,identifier2) identifier1 ## identifier2
 #define G_PASTE(identifier1,identifier2)      G_PASTE_ARGS (identifier1, identifier2)
-#if !defined(__cplusplus) && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+#if !defined(__cplusplus) && defined(__STDC_VERSION__) && \
+    (__STDC_VERSION__ >= 201112L || g_macro__has_feature(c_static_assert) || g_macro__has_extension(c_static_assert))
 #define G_STATIC_ASSERT(expr) _Static_assert (expr, "Expression evaluates to false")
 #elif (defined(__cplusplus) && __cplusplus >= 201103L) || \
       (defined(__cplusplus) && defined (_MSC_VER) && (_MSC_VER >= 1600)) || \

meson.build

@@ -14,18 +14,23 @@ cxx = meson.get_compiler('cpp')
 
 cc_can_run = not meson.is_cross_build() or meson.has_exe_wrapper()
 
-if cc.get_id() == 'msvc'
+if cc.get_argument_syntax() == 'msvc'
   # Ignore several spurious warnings for things glib does very commonly
+  # (also for clang-cl)
+  add_project_arguments('/FImsvc_recommended_pragmas.h',language : 'c')
+endif
+
+if cc.get_id() == 'msvc'
   # If a warning is completely useless and spammy, use '/wdXXXX' to suppress it
   # If a warning is harmless but hard to fix, use '/woXXXX' so it's shown once
   # NOTE: Only add warnings here if you are sure they're spurious
   add_project_arguments('/wd4035', '/wd4715', '/wd4116',
-    '/wd4046', '/wd4068', '/wo4090', '/FImsvc_recommended_pragmas.h',language : 'c')
+    '/wd4046', '/wd4068', '/wo4090',language : 'c')
+  # Set the input and exec encoding to utf-8, like is the default with GCC
+  add_project_arguments(cc.get_supported_arguments(['/utf-8']), language: 'c')
   # Disable SAFESEH with MSVC for plugins and libs that use external deps that
   # are built with MinGW
   noseh_link_args = ['/SAFESEH:NO']
-  # Set the input and exec encoding to utf-8, like is the default with GCC
-  add_project_arguments(cc.get_supported_arguments(['/utf-8']), language: 'c')
 else
   noseh_link_args = []
   # -mms-bitfields vs -fnative-struct ?

msvc_recommended_pragmas.h

@@ -1,10 +1,11 @@
 #ifndef _MSC_VER
-#pragma error "This header is for Microsoft VC only."
+#pragma error "This header is for Microsoft VC or clang-cl only."
 #endif /* _MSC_VER */
 
 /* Make MSVC more pedantic, this is a recommended pragma list
  * from _Win32_Programming_ by Rector and Newcomer.
  */
+#ifndef __clang__
 #pragma warning(error:4002) /* too many actual parameters for macro */
 #pragma warning(error:4003) /* not enough actual parameters for macro */
 #pragma warning(1:4010)     /* single-line comment contains line-continuation character */
@@ -33,6 +34,7 @@
 #pragma warning(disable:4305)   /* No truncation from int to char warnings */
 
 #pragma warning(error:4819) /* The file contains a character that cannot be represented in the current code page */
+#endif                      /* __clang__ */
 
 /* work around Microsoft's premature attempt to deprecate the C-Library */
 #define _CRT_SECURE_NO_WARNINGS