meson/test cases/common/256 subproject extracted ob.../foo.c

#if defined _WIN32 || defined __CYGWIN__
  #define DLL_IMPORT __declspec(dllimport)
#else
  #define DLL_IMPORT
#endif

int DLL_IMPORT cppfunc(void);

int otherfunc(void) {
    return cppfunc() != 42;
}
add compilers from extracted objects directly to build targets In order to reliably link to static libraries or individual object files, we need to take their languages into account as well. For static libraries this is easy: we just add the static library's list of compilers to the build target. For extracted objects, we need to only add the ones for the objects we use. But we did this really inefficiently -- in fact, downright terribly. We iterated over all source files from the extracted objects, then tried to look up a new compiler for them. Even though the extracted objects already had a list of compilers! This broke once compilers were made per-subproject, because while the extracted objects have a reference to all the compilers it needs (just like static archives do, actually) we might not actually be able to look up that compiler from scratch inside the current subproject. Fix this by asking the extracted objects to categorize all its own sources and return the compilers we want. Fixes #10579 2 years ago			`#if defined _WIN32 \|\| defined __CYGWIN__`
			`#define DLL_IMPORT __declspec(dllimport)`
			`#else`
			`#define DLL_IMPORT`
			`#endif`

			`int DLL_IMPORT cppfunc(void);`

			`int otherfunc(void) {`
			`return cppfunc() != 42;`
			`}`