cmake: fix dll exports

move WEBP_EXTERN definition from Makefile.vc to webp/types.h using the
existing WEBP_DLL define to control its declaration to
__declspec(dllexport); the same is done for SHARPYUV_EXTERN

Change-Id: Iecea360305bdd19a878255470a00b9dcc344c730

CMakeLists.txt

@@ -120,6 +120,10 @@ if(WEBP_UNICODE)
   add_definitions(-DUNICODE -D_UNICODE)
 endif()
 
+if(MSVC AND BUILD_SHARED_LIBS)
+  add_definitions(-DWEBP_DLL)
+endif()
+
 set(prefix ${CMAKE_INSTALL_PREFIX})
 set(exec_prefix "\$\{prefix\}")
 set(libdir "\$\{prefix\}/lib")

Makefile.vc

@@ -119,8 +119,7 @@ LIBWEBP = $(DIRLIB)\$(LIBWEBP_BASENAME).lib
 LIBWEBPMUX = $(DIRLIB)\$(LIBWEBPMUX_BASENAME).lib
 LIBWEBPDEMUX = $(DIRLIB)\$(LIBWEBPDEMUX_BASENAME).lib
 !ELSE IF "$(DLLBUILD)" == "TRUE"
-DLLINC = webp_dll.h
-CC     = $(CC) /I$(DIROBJ) /FI$(DLLINC) $(RTLIB) /DWEBP_DLL
+CC     = $(CC) /I$(DIROBJ) $(RTLIB) /DWEBP_DLL
 LIBWEBPDECODER = $(DIRLIB)\$(LIBWEBPDECODER_BASENAME)_dll.lib
 LIBWEBP = $(DIRLIB)\$(LIBWEBP_BASENAME)_dll.lib
 LIBWEBPMUX = $(DIRLIB)\$(LIBWEBPMUX_BASENAME)_dll.lib
@@ -425,9 +424,6 @@ $(LIBWEBPDEMUX): $(LIBWEBPDEMUX_OBJS)
 $(LIBWEBP_OBJS) $(LIBWEBPMUX_OBJS) $(LIBWEBPDEMUX_OBJS): $(OUTPUT_DIRS)
 
 !IF "$(DLLBUILD)" == "TRUE"
-$(LIBWEBP_OBJS) $(LIBWEBPMUX_OBJS) $(LIBWEBPDEMUX_OBJS): \
-    $(DIROBJ)\$(DLLINC)
-
 {$(DIROBJ)}.c{$(DIROBJ)}.obj:
 	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$@  $<
 
@@ -446,9 +442,6 @@ $(LIBWEBPDEMUX): $(LIBWEBP) $(DIROBJ)\demux\$(LIBWEBPDEMUX_BASENAME:_debug=).res
 $(LIBWEBPDECODER) $(LIBWEBP) $(LIBWEBPMUX) $(LIBWEBPDEMUX):
 	$(LNKDLL) /out:$(DIRBIN)\$(@B:_dll=.dll) /implib:$@ $(LFLAGS) $**
 	-xcopy $(DIROBJ)\*.pdb $(DIRLIB) /y
-
-clean::
-	@-erase /s $(DIROBJ)\$(DLLINC) 2> NUL
 !ELSE
 $(LIBWEBPDECODER) $(LIBWEBP) $(LIBWEBPMUX) $(LIBWEBPDEMUX):
 	$(LNKLIB) /out:$@ $**
@@ -458,13 +451,6 @@ $(LIBWEBPDECODER) $(LIBWEBP) $(LIBWEBPMUX) $(LIBWEBPDEMUX):
 $(OUTPUT_DIRS):
 	@if not exist "$(@)" mkdir "$(@)"
 
-# generate a helper include to define WEBP_EXTERN suitable for the DLL build
-$(DIROBJ)\$(DLLINC):
-	@echo #ifndef WEBP_DLL_H_ > $@
-	@echo #define WEBP_DLL_H_ >> $@
-	@echo #define WEBP_EXTERN __declspec(dllexport) >> $@
-	@echo #endif  /* WEBP_DLL_H_ */ >> $@
-
 .SUFFIXES: .c .obj .res .exe
 # File-specific flag builds. Note batch rules take precedence over wildcards,
 # so for now name each file individually.

sharpyuv/sharpyuv.h

@@ -27,7 +27,11 @@ extern "C" {
 #if defined(__GNUC__) && __GNUC__ >= 4
 #define SHARPYUV_EXTERN extern __attribute__((visibility("default")))
 #else
+#if defined(_MSC_VER) && defined(WEBP_DLL)
+#define SHARPYUV_EXTERN __declspec(dllexport)
+#else
 #define SHARPYUV_EXTERN extern
+#endif /* _MSC_VER && WEBP_DLL */
 #endif /* __GNUC__ >= 4 */
 #endif /* WEBP_EXTERN */
 #endif /* SHARPYUV_EXTERN */

src/webp/types.h

@@ -42,7 +42,11 @@ typedef long long int int64_t;
 # if defined(__GNUC__) && __GNUC__ >= 4
 #  define WEBP_EXTERN extern __attribute__ ((visibility ("default")))
 # else
-#  define WEBP_EXTERN extern
+#  if defined(_MSC_VER) && defined(WEBP_DLL)
+#   define WEBP_EXTERN __declspec(dllexport)
+#  else
+#   define WEBP_EXTERN extern
+#  endif
 # endif  /* __GNUC__ >= 4 */
 #endif  /* WEBP_EXTERN */