From 45feb55decb31602190b1157f36b0813e18f6385 Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Tue, 21 Feb 2012 13:44:39 -0800
Subject: [PATCH] expose WebPFree function for DLL builds

This allows managed code (e.g., C#) to free buffers returned by the API
instead of relying on free().
Based on suggestion from Steven (grokys at googlemail dot com).
Fixes issue #109.

Change-Id: I94826a77f6f4cb6e331c454f994c964e2e448cae
---
 Makefile.vc | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/Makefile.vc b/Makefile.vc
index f5075bdf..6c12f6b4 100644
--- a/Makefile.vc
+++ b/Makefile.vc
@@ -82,6 +82,7 @@ STATICLIBBUILD = TRUE
 !ELSE IF "$(CFG)" == "debug-static"
 TARGET         = $(LIB_NAME_DEBUG).lib
 CC             = $(CCDEBUG)
+RTLIB          = $(RTLIBD)
 STATICLIBBUILD = TRUE
 !ELSE IF "$(CFG)" == "release-dynamic"
 TARGETDLL = $(LIB_NAME).dll
@@ -92,6 +93,7 @@ DLLBUILD  = TRUE
 TARGETDLL = $(LIB_NAME_DEBUG).dll
 TARGET    = $(IMPLIB_NAME_DEBUG).lib
 CC        = $(CCDEBUG)
+RTLIB     = $(RTLIBD)
 DLLBUILD  = TRUE
 !ENDIF
 
@@ -100,9 +102,11 @@ CC     = $(CC) $(RTLIB)
 LNK    = $(LNKLIB) /out:$(DIRLIB)\$(TARGET)
 CFGSET = TRUE
 !ELSE IF "$(DLLBUILD)" == "TRUE"
+DLLC   = webp_dll.c
 DLLINC = webp_dll.h
 CC     = $(CC) /I$(DIROBJ) /FI$(DLLINC) $(RTLIB) /DWEBP_DLL
 LNK    = $(LNKDLL) /out:$(DIRBIN)\$(TARGETDLL) /implib:$(DIRLIB)\$(TARGET)
+X_OBJS = $(DIROBJ)\$(DLLC:.c=.obj)
 CFGSET = TRUE
 !ENDIF
 
@@ -184,7 +188,7 @@ X_OBJS= \
     $(DIROBJ)\utils\quant_levels.obj \
     $(DIROBJ)\utils\tcoder.obj \
     $(DIROBJ)\utils\thread.obj \
-    $(RESOURCE) \
+    $(X_OBJS) \
 
 EXAMPLES_OBJS = \
     $(DIROBJ)\examples\cwebp.obj \
@@ -211,9 +215,12 @@ $(DIRLIB)\$(TARGET): $(X_OBJS)
 $(X_OBJS): $(OUTPUT_DIRS)
 
 !IF "$(DLLBUILD)" == "TRUE"
-$(X_OBJS): $(DIROBJ)\$(DLLINC)
+$(X_OBJS): $(DIROBJ)\$(DLLINC) $(DIROBJ)\$(DLLC)
+
+{$(DIROBJ)}.c{$(DIROBJ)}.obj:
+	$(CC) $(CFLAGS) /Fo"$@"  $<
 clean::
-	@-erase /s $(DIROBJ)\$(DLLINC) 2> NUL
+	@-erase /s $(DIROBJ)\$(DLLC) $(DIROBJ)\$(DLLINC) 2> NUL
 !ENDIF
 
 $(EXAMPLES_OBJS): $(DIRLIB)\$(TARGET)
@@ -228,6 +235,16 @@ $(DIROBJ)\$(DLLINC):
 	@echo #define WEBP_EXTERN(type) __declspec(dllexport) type >> $@
 	@echo #endif  /* WEBP_DLL_H_ */ >> $@
 
+# expose a WebPFree() function for use in managed code
+$(DIROBJ)\$(DLLC): $(DIROBJ)\$(DLLINC)
+	@echo #include ^<stdlib.h^> > $@
+	@echo #include "webp_dll.h" >> $@
+	@echo // This function should be used in place of free() for memory >> $@
+	@echo // returned by the WebP API. >> $@
+	@echo WEBP_EXTERN(void) WebPFree(void* ptr) { >> $@
+	@echo   free(ptr); >> $@
+	@echo } >> $@
+
 .SUFFIXES: .c .obj .res .exe
 {examples}.c{$(DIROBJ)\examples}.obj:
 	$(CC) $(CFLAGS) /Fo"$@"  $<