Provide a common set of routines in Version.h that return Subversion

branch/revision information. Use that information in the driver,
rather than one-off branch/revision computation. 

llvm-svn: 83321

3 files changed, 24 insertions, 16 deletions

diff --git a/clang/lib/Basic/CMakeLists.txt b/clang/lib/Basic/CMakeLists.txt
index e0e9a10e519..527ebf96593 100644
--- a/clang/lib/Basic/CMakeLists.txt
+++ b/clang/lib/Basic/CMakeLists.txt
@@ -11,8 +11,19 @@ add_clang_library(clangBasic
   TargetInfo.cpp
   Targets.cpp
   TokenKinds.cpp
+  Version.cpp
   )
 
+# Determine Subversion revision.
+# FIXME: This only gets updated when CMake is run, so this revision number
+# may be out-of-date!
+find_package(Subversion)
+if (Subversion_FOUND)
+  Subversion_WC_INFO(${CLANG_SOURCE_DIR} CLANG)
+  set_source_files_properties(Version.cpp
+    PROPERTIES COMPILE_DEFINITIONS "SVN_REVISION=\"${CLANG_WC_REVISION}\"")
+endif()
+
 add_dependencies(clangBasic 
                  ClangDiagnosticAnalysis
                  ClangDiagnosticAST
diff --git a/clang/lib/Basic/Makefile b/clang/lib/Basic/Makefile
index a81f03b4f71..46c725998c9 100644
--- a/clang/lib/Basic/Makefile
+++ b/clang/lib/Basic/Makefile
@@ -23,3 +23,14 @@ CPPFLAGS += -I$(PROJ_SRC_DIR)/../../include -I$(PROJ_OBJ_DIR)/../../include
 
 include $(LEVEL)/Makefile.common
 
+SVN_REVISION := $(shell cd $(PROJ_SRC_DIR)/../.. && svnversion)
+
+CPP.Defines += -I$(PROJ_SRC_DIR)/../../include -I$(PROJ_OBJ_DIR)/../../include \
+         -DSVN_REVISION='"$(SVN_REVISION)"'
+
+$(ObjDir)/.ver-svn .ver: $(ObjDir)/.dir
+	@if [ '$(SVN_REVISION)' != '$(shell cat $(ObjDir)/.ver-svn 2>/dev/null)' ]; then\
+		echo '$(SVN_REVISION)' > $(ObjDir)/.ver-svn;			\
+	fi
+$(ObjDir)/.ver-svn: .ver
+$(ObjDir)/Version.o: $(ObjDir)/.ver-svn
diff --git a/clang/lib/Basic/Version.cpp b/clang/lib/Basic/Version.cpp
index 3a51ccb5e72..9699ee416be 100644
--- a/clang/lib/Basic/Version.cpp
+++ b/clang/lib/Basic/Version.cpp
@@ -39,24 +39,10 @@ const char *getClangSubversionPath() {
 
 unsigned getClangSubversionRevision() {
 #ifndef SVN_REVISION
+  // Subversion was not available at build time?
   return 0;
 #else
-  // What follows is an evil trick. We can end up getting three different
-  // kinds of results when asking for the Subversion information:
-  //   - if SVN_REVISION is a number, we return that number (adding 0 to it is
-  //     harmless).
-  //   - if SVN_REVISION is "exported" (for an tree without any Subversion 
-  //     info), we end up referencing the local variable "exported" and adding
-  //     zero to it, and we return 0.
-  //   - if SVN_REVISION is empty (because "svn info" returned no results),
-  //     the "+" turns into a unary "+" operator and we return 0.
-  //
-  // Making this less ugly requires doing more computation in the CMake- and
-  // Makefile-based build systems, with all sorts of checking to make sure we
-  // don't end up breaking this build. It's better this way. Really.
-  const unsigned exported = 0;
-  (void)exported;
-  return SVN_REVISION + 0;
+  return strtol(SVN_REVISION, 0, 10);
 #endif
 }