use CMake headers via a build-time switch instead of __has_include

Author: QuietMisdreavus

api_test/CMakeLists.txt

@@ -34,3 +34,5 @@ endif()
 if (MSVC AND MSVC_VERSION GREATER_EQUAL 1910)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /std:c11")
 endif()
+
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DCMARK_USE_CMAKE_HEADERS")

extensions/CMakeLists.txt

@@ -103,6 +103,9 @@ CHECK_C_SOURCE_COMPILES(
   "int main() { __builtin_expect(0,0); return 0; }"
   HAVE___BUILTIN_EXPECT)
 
+# Use CMake's generated headers instead of the Swift package prebuilt ones
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DCMARK_USE_CMAKE_HEADERS")
+
 # Always compile with warnings
 if(MSVC)
   # Force to always compile with W4

extensions/include/extensions-export.h

@@ -1,10 +1,13 @@
-#if __has_include("cmark-gfm-extensions_export.h")
-#include "cmark-gfm-extensions_export.h"
-#else
-
 #ifndef CMARK_GFM_EXTENSIONS_EXPORT_H
 #define CMARK_GFM_EXTENSIONS_EXPORT_H
 
+#ifdef CMARK_USE_CMAKE_HEADERS
+// if the CMake config header exists, use that instead of this Swift package prebuilt one
+// we need to undefine the header guard, since export.h uses the same one
+#undef CMARK_GFM_EXTENSIONS_EXPORT_H
+#include "cmark-gfm-extensions_export.h"
+#else
+
 #ifdef CMARK_GFM_EXTENSIONS_STATIC_DEFINE
 #  define CMARK_GFM_EXTENSIONS_EXPORT
 #  define CMARK_GFM_EXTENSIONS_NO_EXPORT

src/CMakeLists.txt

@@ -174,6 +174,9 @@ CONFIGURE_FILE(
   ${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
   ${CMAKE_CURRENT_BINARY_DIR}/config.h)
 
+# Use CMake's generated headers instead of the Swift package prebuilt ones
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DCMARK_USE_CMAKE_HEADERS")
+
 # Always compile with warnings
 if(MSVC)
   # Force to always compile with W4

src/include/cmark-gfm_config.h

@@ -1,10 +1,13 @@
-#if __has_include("config.h")
-#include "config.h"
-#else
-
 #ifndef CMARK_CONFIG_H
 #define CMARK_CONFIG_H
 
+#ifdef CMARK_USE_CMAKE_HEADERS
+// if the CMake config header exists, use that instead of this Swift package prebuilt one
+// we need to undefine the header guard, since config.h uses the same one
+#undef CMARK_CONFIG_H
+#include "config.h"
+#else
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -78,6 +81,6 @@ CMARK_INLINE int c99_snprintf(char *outBuf, size_t size, const char *format, ...
 }
 #endif
 
-#endif /* CMARK_CONFIG_H */
+#endif /* not CMARK_USE_CMAKE_HEADERS */
 
-#endif /* config.h */
+#endif /* not CMARK_CONFIG_H */

src/include/export.h

@@ -1,10 +1,13 @@
-#if __has_include("cmark-gfm_export.h")
-#include "cmark-gfm_export.h"
-#else
-
 #ifndef CMARK_GFM_EXPORT_H
 #define CMARK_GFM_EXPORT_H
 
+#ifdef CMARK_USE_CMAKE_HEADERS
+// if the CMake config header exists, use that instead of this Swift package prebuilt one
+// we need to undefine the header guard, since export.h uses the same one
+#undef CMARK_GFM_EXPORT_H
+#include "cmark-gfm_export.h"
+#else
+
 #ifdef CMARK_GFM_STATIC_DEFINE
 #  define CMARK_GFM_EXPORT
 #  define CMARK_GFM_NO_EXPORT
@@ -42,6 +45,6 @@
 #  define CMARK_GFM_DEPRECATED_NO_EXPORT CMARK_GFM_NO_EXPORT CMARK_GFM_DEPRECATED
 #endif
 
-#endif /* CMARK_GFM_EXPORT_H */
+#endif /* not CMARK_USE_CMAKE_HEADERS */
 
-#endif /* "cmark-gfm_export.h" */
+#endif /* not CMARK_GFM_EXPORT_H */