2010-01-03 Maciej Stachowiak <mjs@apple.com>

        Reviewed by Eric Seidel.

        Update wtf/Platform.h to document the new system for porting macros.
        https://bugs.webkit.org/show_bug.cgi?id=33130

        * wtf/Platform.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@52706 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/JavaScriptCore/ChangeLog b/JavaScriptCore/ChangeLog
index 42a3956a7dced90a10e923250f5739ab3cf7f1c1..d20487f3660b72cc1996ce700954f1ff5e5097eb 100644 (file)
--- a/JavaScriptCore/ChangeLog
+++ b/JavaScriptCore/ChangeLog
@@ -1,3 +1,12 @@
+2010-01-03  Maciej Stachowiak  <mjs@apple.com>
+
+        Reviewed by Eric Seidel.
+
+        Update wtf/Platform.h to document the new system for porting macros.
+        https://bugs.webkit.org/show_bug.cgi?id=33130
+
+        * wtf/Platform.h:
+
 2009-12-29  Laszlo Gombos  <laszlo.1.gombos@nokia.com>
 
         Reviewed by Maciej Stachowiak.

diff --git a/JavaScriptCore/wtf/Platform.h b/JavaScriptCore/wtf/Platform.h
index 95eb63ad424c2c02591295f0e5905f2b4d3d5194..73019bb832c9650377e9ec9f990027ce3fe01dab 100644 (file)
--- a/JavaScriptCore/wtf/Platform.h
+++ b/JavaScriptCore/wtf/Platform.h
@@ -27,11 +27,27 @@
 #ifndef WTF_Platform_h
 #define WTF_Platform_h
 
-/* PLATFORM handles OS, operating environment, graphics API, and CPU */
+/* PLATFORM handles OS, operating environment, graphics API, and
+   CPU. This macro will be phased out in favor of platform adaptation
+   macros, policy decision macros, and top-level port definitions. */
 #define PLATFORM(WTF_FEATURE) (defined WTF_PLATFORM_##WTF_FEATURE  && WTF_PLATFORM_##WTF_FEATURE)
+
+/* == Platform adaptation macros: these describe properties of the target environment. */
+
+/* COMPILER() - the compiler being used to build the project */
 #define COMPILER(WTF_FEATURE) (defined WTF_COMPILER_##WTF_FEATURE  && WTF_COMPILER_##WTF_FEATURE)
+/* CPU() - the target CPU architecture */
+#define CPU(WTF_FEATURE) (defined WTF_CPU_##WTF_FEATURE  && WTF_CPU_##WTF_FEATURE)
+/* HAVE() - specific system features (headers, functions or similar) that are present or not */
 #define HAVE(WTF_FEATURE) (defined HAVE_##WTF_FEATURE  && HAVE_##WTF_FEATURE)
+/* OS() - underlying operating system; only to be used for mandated low-level services like 
+   virtual memory, not to choose a GUI toolkit */
+#define OS(WTF_FEATURE) (defined WTF_OS_##WTF_FEATURE  && WTF_OS_##WTF_FEATURE)
+
+/* == Policy decision macros: these define policy choices for a particular port. */
+/* USE() - use a particular third-party library or optional OS service */
 #define USE(WTF_FEATURE) (defined WTF_USE_##WTF_FEATURE  && WTF_USE_##WTF_FEATURE)
+/* ENABLE() - turn on a specific feature of WebKit */
 #define ENABLE(WTF_FEATURE) (defined ENABLE_##WTF_FEATURE  && ENABLE_##WTF_FEATURE)
 
 /* Operating systems - low-level dependencies */