[CMake] Unify scripts for generating VCS headers

Previously, there were two different scripts for generating VCS headers:
one used by LLVM and one used by Clang. They were both similar, but
different. They were both broken in their own ways, for example the one
used by Clang didn't properly handle monorepo resulting in an incorrect
version information reported by Clang.

This change unifies two the scripts by introducing a new script that's
used from both LLVM and Clang, ensures that the new script supports both
monorepo and standalone SVN and Git setups, and removes the old scripts.

Differential Revision: https://reviews.llvm.org/D57063

llvm-svn: 352729

2 files changed, 28 insertions, 42 deletions

diff --git a/clang/lib/Basic/CMakeLists.txt b/clang/lib/Basic/CMakeLists.txt
index 8b3aa0f1e97..7e1543bb898 100644
--- a/clang/lib/Basic/CMakeLists.txt
+++ b/clang/lib/Basic/CMakeLists.txt
@@ -4,45 +4,34 @@ set(LLVM_LINK_COMPONENTS
   Support
   )
 
-find_first_existing_vc_file(llvm_vc "${LLVM_MAIN_SRC_DIR}")
-find_first_existing_vc_file(clang_vc "${CLANG_SOURCE_DIR}")
+find_first_existing_vc_file("${LLVM_MAIN_SRC_DIR}" llvm_vc)
+find_first_existing_vc_file("${CLANG_SOURCE_DIR}" clang_vc)
 
 # The VC revision include that we want to generate.
-set(version_inc "${CMAKE_CURRENT_BINARY_DIR}/SVNVersion.inc")
+set(version_inc "${CMAKE_CURRENT_BINARY_DIR}/VCSRevision.h")
 
-set(get_svn_script "${LLVM_CMAKE_PATH}/GetSVN.cmake")
+set(get_svn_script "${LLVM_CMAKE_PATH}/GenerateVersionFromVCS.cmake")
 
-if(DEFINED llvm_vc AND DEFINED clang_vc)
-  # Create custom target to generate the VC revision include.
-  add_custom_command(OUTPUT "${version_inc}"
-    DEPENDS "${llvm_vc}" "${clang_vc}" "${get_svn_script}"
-    COMMAND
-    ${CMAKE_COMMAND} "-DFIRST_SOURCE_DIR=${LLVM_MAIN_SRC_DIR}"
-                     "-DFIRST_NAME=LLVM"
-                     "-DSECOND_SOURCE_DIR=${CLANG_SOURCE_DIR}"
-                     "-DSECOND_NAME=SVN"
-                     "-DHEADER_FILE=${version_inc}"
-                     -P "${get_svn_script}")
-
-  # Mark the generated header as being generated.
-  set_source_files_properties("${version_inc}"
-    PROPERTIES GENERATED TRUE
-               HEADER_FILE_ONLY TRUE)
+if(llvm_vc)
+  set(llvm_source_dir ${LLVM_MAIN_SRC_DIR})
+endif()
+if(clang_vc)
+  set(clang_source_dir ${CLANG_SOURCE_DIR})
+endif()
 
-  # Tell Version.cpp that it needs to build with -DHAVE_SVN_VERSION_INC.
-  set_source_files_properties(Version.cpp
-    PROPERTIES COMPILE_DEFINITIONS "HAVE_SVN_VERSION_INC")
-else()
-  # Not producing a VC revision include.
-  set(version_inc)
+# Create custom target to generate the VC revision include.
+add_custom_command(OUTPUT "${version_inc}"
+  DEPENDS "${llvm_vc}" "${clang_vc}" "${get_svn_script}"
+  COMMAND ${CMAKE_COMMAND} "-DNAMES=LLVM\;CLANG"
+                           "-DLLVM_SOURCE_DIR=${llvm_source_dir}"
+                           "-DCLANG_SOURCE_DIR=${clang_source_dir}"
+                           "-DHEADER_FILE=${version_inc}"
+                           -P "${get_svn_script}")
 
-  # Being able to force-set the SVN revision in cases where it isn't available
-  # is useful for performance tracking, and matches compatibility from autoconf.
-  if(SVN_REVISION)
-    set_source_files_properties(Version.cpp
-      PROPERTIES COMPILE_DEFINITIONS "SVN_REVISION=\"${SVN_REVISION}\"")
-  endif()
-endif()
+# Mark the generated header as being generated.
+set_source_files_properties("${version_inc}"
+  PROPERTIES GENERATED TRUE
+             HEADER_FILE_ONLY TRUE)
 
 add_clang_library(clangBasic
   Attributes.cpp
diff --git a/clang/lib/Basic/Version.cpp b/clang/lib/Basic/Version.cpp
index 4ed081d2779..bbaeafedd94 100644
--- a/clang/lib/Basic/Version.cpp
+++ b/clang/lib/Basic/Version.cpp
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "VCSRevision.h"
 #include "clang/Basic/Version.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Config/config.h"
@@ -17,23 +18,19 @@
 #include <cstdlib>
 #include <cstring>
 
-#ifdef HAVE_SVN_VERSION_INC
-#  include "SVNVersion.inc"
-#endif
-
 namespace clang {
 
 std::string getClangRepositoryPath() {
 #if defined(CLANG_REPOSITORY_STRING)
   return CLANG_REPOSITORY_STRING;
 #else
-#ifdef SVN_REPOSITORY
-  StringRef URL(SVN_REPOSITORY);
+#ifdef CLANG_REPOSITORY
+  StringRef URL(CLANG_REPOSITORY);
 #else
   StringRef URL("");
 #endif
 
-  // If the SVN_REPOSITORY is empty, try to use the SVN keyword. This helps us
+  // If the CLANG_REPOSITORY is empty, try to use the SVN keyword. This helps us
   // pick up a tag in an SVN export, for example.
   StringRef SVNRepository("$URL$");
   if (URL.empty()) {
@@ -71,8 +68,8 @@ std::string getLLVMRepositoryPath() {
 }
 
 std::string getClangRevision() {
-#ifdef SVN_REVISION
-  return SVN_REVISION;
+#ifdef CLANG_REVISION
+  return CLANG_REVISION;
 #else
   return "";
 #endif