[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

Author: petrhosek

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

clang/lib/Basic/Version.cpp

@@ -10,30 +10,27 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "VCSRevision.h"
 #include "clang/Basic/Version.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Config/config.h"
 #include "llvm/Support/raw_ostream.h"
 #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

llvm/CMakeLists.txt

@@ -200,7 +200,7 @@ endif()
 include(VersionFromVCS)
 
 option(LLVM_APPEND_VC_REV
-  "Embed the version control system revision id in LLVM" ON)
+  "Embed the version control system revision in LLVM" ON)
 
 set(PACKAGE_NAME LLVM)
 set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
@@ -752,13 +752,12 @@ set(LLVM_SRPM_USER_BINARY_SPECFILE ${CMAKE_CURRENT_SOURCE_DIR}/llvm.spec.in
 set(LLVM_SRPM_BINARY_SPECFILE ${CMAKE_CURRENT_BINARY_DIR}/llvm.spec)
 set(LLVM_SRPM_DIR "${CMAKE_CURRENT_BINARY_DIR}/srpm")
 
-# SVN_REVISION and GIT_COMMIT get set by the call to add_version_info_from_vcs.
-# DUMMY_VAR contains a version string which we don't care about.
-add_version_info_from_vcs(DUMMY_VAR)
-if ( SVN_REVISION )
-  set(LLVM_RPM_SPEC_REVISION "r${SVN_REVISION}")
-elseif ( GIT_COMMIT )
-  set (LLVM_RPM_SPEC_REVISION "g${GIT_COMMIT}")
+get_source_info(${CMAKE_CURRENT_SOURCE_DIR} revision repository)
+string(LENGTH "${revision}" revision_length)
+if(revision MATCHES "^[0-9]+$" AND revision_length LESS 40)
+  set(LLVM_RPM_SPEC_REVISION "r${revision}")
+else()
+  set(LLVM_RPM_SPEC_REVISION "${revision}")
 endif()
 
 configure_file(

llvm/cmake/modules/AddLLVM.cmake

@@ -1707,35 +1707,35 @@ function(setup_dependency_debugging name)
   set_target_properties(${name} PROPERTIES RULE_LAUNCH_COMPILE ${sandbox_command})
 endfunction()
 
-# Figure out if we can track VC revisions.
-function(find_first_existing_file out_var)
-  foreach(file ${ARGN})
-    if(EXISTS "${file}")
-      set(${out_var} "${file}" PARENT_SCOPE)
-      return()
-    endif()
-  endforeach()
-endfunction()
-
-macro(find_first_existing_vc_file out_var path)
-    find_program(git_executable NAMES git git.exe git.cmd)
-    # Run from a subdirectory to force git to print an absolute path.
-    execute_process(COMMAND ${git_executable} rev-parse --git-dir
-      WORKING_DIRECTORY ${path}/cmake
-      RESULT_VARIABLE git_result
-      OUTPUT_VARIABLE git_dir
-      ERROR_QUIET)
-    if(git_result EQUAL 0)
-      string(STRIP "${git_dir}" git_dir)
-      set(${out_var} "${git_dir}/logs/HEAD")
-      # some branchless cases (e.g. 'repo') may not yet have .git/logs/HEAD
-      if (NOT EXISTS "${git_dir}/logs/HEAD")
-        file(WRITE "${git_dir}/logs/HEAD" "")
+function(find_first_existing_vc_file path out_var)
+  if(EXISTS "${path}/.svn")
+    set(svn_files
+      "${path}/.svn/wc.db"   # SVN 1.7
+      "${path}/.svn/entries" # SVN 1.6
+    )
+    foreach(file IN LISTS svn_files)
+      if(EXISTS "${file}")
+        set(${out_var} "${file}" PARENT_SCOPE)
+        return()
+      endif()
+    endforeach()
+  else()
+    find_package(Git)
+    if(GIT_FOUND)
+      execute_process(COMMAND ${GIT_EXECUTABLE} rev-parse --git-dir
+        WORKING_DIRECTORY ${path}
+        RESULT_VARIABLE git_result
+        OUTPUT_VARIABLE git_output
+        ERROR_QUIET)
+      if(git_result EQUAL 0)
+        string(STRIP "${git_output}" git_output)
+        get_filename_component(git_dir ${git_output} ABSOLUTE BASE_DIR ${path})
+        # Some branchless cases (e.g. 'repo') may not yet have .git/logs/HEAD
+        if (NOT EXISTS "${git_dir}/logs/HEAD")
+          file(WRITE "${git_dir}/logs/HEAD" "")
+        endif()
+        set(${out_var} "${git_dir}/logs/HEAD" PARENT_SCOPE)
       endif()
-    else()
-      find_first_existing_file(${out_var}
-        "${path}/.svn/wc.db"   # SVN 1.7
-        "${path}/.svn/entries" # SVN 1.6
-      )
     endif()
-endmacro()
+  endif()
+endfunction()

llvm/cmake/modules/GenerateVersionFromCVS.cmake

@@ -0,0 +1,53 @@
+# CMake script that writes version control information to a header.
+#
+# Input variables:
+#   NAMES             - A list of names for each of the source directories.
+#   <NAME>_SOURCE_DIR - A path to source directory for each name in NAMES.
+#   HEADER_FILE       - The header file to write
+#
+# The output header will contain macros <NAME>_REPOSITORY and <NAME>_REVISION,
+# where "<NAME>" is substituted with the names specified in the input variables,
+# for each of the <NAME>_SOURCE_DIR given.
+
+get_filename_component(LLVM_DIR "${CMAKE_SCRIPT_MODE_FILE}" PATH)
+get_filename_component(LLVM_DIR "${LLVM_DIR}" PATH)
+get_filename_component(LLVM_DIR "${LLVM_DIR}" PATH)
+
+list(APPEND CMAKE_MODULE_PATH "${LLVM_DIR}/cmake/modules")
+
+include(VersionFromVCS)
+
+# Handle strange terminals
+set(ENV{TERM} "dumb")
+
+function(append_info name path)
+  if(path)
+    get_source_info("${path}" revision repository)
+  endif()
+  if(revision)
+    file(APPEND "${HEADER_FILE}.tmp"
+      "#define ${name}_REVISION \"${revision}\"\n")
+  else()
+    file(APPEND "${HEADER_FILE}.tmp"
+      "#undef ${name}_REVISION\n")
+  endif()
+  if(repository)
+    file(APPEND "${HEADER_FILE}.tmp"
+      "#define ${name}_REPOSITORY \"${repository}\"\n")
+  else()
+    file(APPEND "${HEADER_FILE}.tmp"
+      "#undef ${name}_REPOSITORY\n")
+  endif()
+endfunction()
+
+foreach(name IN LISTS NAMES)
+  if(NOT DEFINED ${name}_SOURCE_DIR)
+    message(FATAL_ERROR "${name}_SOURCE_DIR is not defined")
+  endif()
+  append_info(${name} "${${name}_SOURCE_DIR}")
+endforeach()
+
+# Copy the file only if it has changed.
+execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different
+  "${HEADER_FILE}.tmp" "${HEADER_FILE}")
+file(REMOVE "${HEADER_FILE}.tmp")