Bug 795433 - Use #define for nsresult values in C code. r=ehsan,glandium; feedback=njn

xpcom/base/Makefile.in

@@ -109,7 +109,8 @@ SDK_HEADERS     = \
 		nsAutoPtr.h \
 		nsError.h \
 		ErrorList.h \
-		ErrorListDefines.h \
+		ErrorListCxxDefines.h \
+		ErrorListCDefines.h \
 		nsISupportsBase.h \
 		nscore.h \
 		nsAtomicRefcnt.h \
@@ -163,10 +164,16 @@ LOCAL_INCLUDES += \
 		-I$(topsrcdir)/xpcom/ds \
 		$(NULL)
 
-# We generate ErrorListDefines.h from ErrorList.h using regex.  The -n option
+# We generate ErrorListCxxDefines.h from ErrorList.h using regex.  The -n option
 # suppresses printing the pattern space, and the p at the end prints it anyway,
 # so we don't print lines that don't match the pattern to start with.
-ErrorListDefines.h: ErrorList.h
+ErrorListCxxDefines.h: ErrorList.h Makefile
 		sed -n 's/.*ERROR(\([A-Z_0-9]*\).*/#define \1 nsresult::\1/p' < $< > $@
 
-GARBAGE += ErrorListDefines.h
+ErrorListCDefines.h: ErrorList.h Makefile
+		sed 's/.*ERROR(\([A-Z_0-9]*\),\( *\)\(.*\))[^)]*/#define \1 \2((nsresult)(\3))/' < $< > $@
+
+GARBAGE += \
+	ErrorListCxxDefines.h \
+	ErrorListCDefines.h \
+	$(NULL)

xpcom/base/nsError.h

@@ -117,16 +117,16 @@
  *   return foo ? F() : NS_ERROR_FAILURE;
  * to fail, because nsresult and nsresult::Enum are two distinct types and
  * either can be converted to the other, so it's ambiguous.  So we have to fall
- * back to a regular enum.  Fortunately, we need to support that anyway for the
- * sake of C, so it's not a big deal.
+ * back to a regular enum.
  */
-#if defined(__cplusplus) && defined(MOZ_HAVE_CXX11_STRONG_ENUMS)
+#if defined(__cplusplus)
+#if defined(MOZ_HAVE_CXX11_STRONG_ENUMS)
   typedef enum class tag_nsresult : uint32_t
-#elif defined(__cplusplus) && defined(MOZ_HAVE_CXX11_ENUM_TYPE)
+#elif defined(MOZ_HAVE_CXX11_ENUM_TYPE)
   /* Need underlying type for workaround of Microsoft compiler (Bug 794734) */
   typedef enum tag_nsresult : uint32_t
 #else
-  /* C, or no strong enums */
+  /* no strong enums */
   typedef enum tag_nsresult
 #endif
   {
@@ -136,11 +136,18 @@
     #undef ERROR
   } nsresult;
 
-#if defined(__cplusplus) && defined(MOZ_HAVE_CXX11_STRONG_ENUMS)
+#if defined(MOZ_HAVE_CXX11_STRONG_ENUMS)
   /* We're using enum classes, so we need #define's to put the constants in
    * global scope for compatibility with old code. */
-  #include "ErrorListDefines.h"
+  #include "ErrorListCxxDefines.h"
 #endif
+#else /* defined(__cplusplus) */
+  /* C enum can't have a value outside the range of 'int'.
+   * C const can't initialize with an expression involving other variables
+   * even if it is const. So we have to fall back to bad old #defines. */
+  typedef uint32_t nsresult;
+  #include "ErrorListCDefines.h"
+#endif /* defined(__cplusplus) */
 
 #undef SUCCESS_OR_FAILURE
 #undef SUCCESS

xpcom/typelib/xpt/src/Makefile.in

@@ -32,6 +32,7 @@ DEFINES		+= -DEXPORT_XPT_API
 # Build libxpt early so that it'll be available to xpidl, which also
 # must be built early.
 export::
+	@$(MAKE) -C ../../../base ErrorListCDefines.h
 	@$(MAKE) libs
 
 # XXX, bug 417045, make -jN combines badly with -save-temps in   
@@ -46,5 +47,6 @@ endif
 
 LOCAL_INCLUDES += \
                 -I../../../ \
+                -I../../../base \
                 -I$(topsrcdir)/xpcom/base \
                 $(NULL)