common: ensure correct import/export declarations of expat with MinGW

The expat library does not seem to recognize MinGW and therefore does
not apply the Microsoft storage class attributes to its function
declarations when using MinGW. Defining XML_USE_MSC_EXTENSIONS forces
it to use those.

Fixes errors like this with MinGW:

C:/tools/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: ../common/CMakeFiles/common_obj.dir/htmllex.c.obj:htmllex.c:(.text+0x1cec): undefined reference to `XML_ParserCreate'

diff --git a/lib/common/htmllex.c b/lib/common/htmllex.c
index a6a347e78fe900c2ce1f585fee380bb315bebc0d..1089c59dceb507c02c0643ba48d29be5d913902c 100644 (file)
--- a/lib/common/htmllex.c
+++ b/lib/common/htmllex.c
@@ -20,6 +20,11 @@
 #include <stddef.h>
 
 #ifdef HAVE_EXPAT
+#ifdef _WIN32
+// ensure that the expat functions get the correct storage class
+// declarations also on MinGW
+#define XML_USE_MSC_EXTENSIONS 1
+#endif
 #include <expat.h>
 #endif