From 01879634f01bdbfac4636ebe03b68e85b20cd664 Mon Sep 17 00:00:00 2001
From: Petr Hosek <phosek@chromium.org>
Date: Wed, 6 Feb 2019 03:51:00 +0000
Subject: [PATCH] [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 and lldb. 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, Clang and lldb, 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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@353268 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Basic/CMakeLists.txt | 56 +++++++++++++++++-----------------------
 lib/Basic/Version.cpp    | 14 +++++-----
 2 files changed, 31 insertions(+), 39 deletions(-)

diff --git a/lib/Basic/CMakeLists.txt b/lib/Basic/CMakeLists.txt
index 8b3aa0f1e972..2770cd31c91f 100644
--- a/lib/Basic/CMakeLists.txt
+++ b/lib/Basic/CMakeLists.txt
@@ -4,45 +4,37 @@ 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}/VCSVersion.inc")
 
-set(get_svn_script "${LLVM_CMAKE_PATH}/GetSVN.cmake")
+set(generate_vcs_version_script "${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}")
+if(llvm_vc)
+  set(llvm_source_dir ${LLVM_MAIN_SRC_DIR})
+endif()
+if(clang_vc)
+  set(clang_source_dir ${CLANG_SOURCE_DIR})
+endif()
 
-  # Mark the generated header as being generated.
-  set_source_files_properties("${version_inc}"
-    PROPERTIES GENERATED TRUE
-               HEADER_FILE_ONLY TRUE)
+# Create custom target to generate the VC revision include.
+add_custom_command(OUTPUT "${version_inc}"
+  DEPENDS "${llvm_vc}" "${clang_vc}" "${generate_vcs_version_script}"
+  COMMAND ${CMAKE_COMMAND} "-DNAMES=\"LLVM;CLANG\""
+                           "-DLLVM_SOURCE_DIR=${llvm_source_dir}"
+                           "-DCLANG_SOURCE_DIR=${clang_source_dir}"
+                           "-DHEADER_FILE=${version_inc}"
+                           -P "${generate_vcs_version_script}")
 
-  # 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)
+# Mark the generated header as being generated.
+set_source_files_properties("${version_inc}"
+  PROPERTIES GENERATED TRUE
+             HEADER_FILE_ONLY TRUE)
 
-  # 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()
+set_property(SOURCE Version.cpp APPEND PROPERTY
+             COMPILE_DEFINITIONS "HAVE_VCS_VERSION_INC")
 
 add_clang_library(clangBasic
   Attributes.cpp
diff --git a/lib/Basic/Version.cpp b/lib/Basic/Version.cpp
index 4ed081d2779e..d6564582e772 100644
--- a/lib/Basic/Version.cpp
+++ b/lib/Basic/Version.cpp
@@ -17,8 +17,8 @@
 #include <cstdlib>
 #include <cstring>
 
-#ifdef HAVE_SVN_VERSION_INC
-#  include "SVNVersion.inc"
+#ifdef HAVE_VCS_VERSION_INC
+#include "VCSVersion.inc"
 #endif
 
 namespace clang {
@@ -27,13 +27,13 @@ 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 +71,8 @@ std::string getLLVMRepositoryPath() {
 }
 
 std::string getClangRevision() {
-#ifdef SVN_REVISION
-  return SVN_REVISION;
+#ifdef CLANG_REVISION
+  return CLANG_REVISION;
 #else
   return "";
 #endif