From b28905a2281d31997fbc9a45c0810624f1a9633d Mon Sep 17 00:00:00 2001
From: Ulrich Germann <ugermann@inf.ed.ac.uk>
Date: Tue, 21 Jul 2020 11:32:08 +0100
Subject: [PATCH] Fix bug in finding path to ./git/log/HEAD if Marian is a
 submodule. (#644)

* Fix bug in finding path to ./git/log/HEAD if Marian is a submodule.
* Build build_info.cpp in build dir, not source dir.
---
 CHANGELOG.md                   |  2 ++
 CMakeLists.txt                 |  5 ++++-
 cmake/GetVersionFromFile.cmake |  2 +-
 src/CMakeLists.txt             | 27 ++++++++++++++-------------
 4 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53fac0c92..d565c05fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - In concatenation make sure that we do not multiply 0 with nan (which results in nan)
 - Change Approx.epsilon(0.01) to Approx.margin(0.001) in unit tests. Tolerance is now
   absolute and not relative. We assumed incorrectly that epsilon is absolute tolerance.
+- Fixed bug in finding .git/logs/HEAD when Marian is a submodule in another project.
+- Properly record cmake variables in the cmake build directory instead of the source tree.
 
 ### Changed
 - Move Simple-WebSocket-Server to submodule
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 836c4099d..2133396d4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -442,8 +442,11 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/common/project_version.h.in
 # Generate build_info.cpp with CMake cache variables
 include(GetCacheVariables)
 
+# make sure src/common/build_info.cpp has been removed
+execute_process(COMMAND rm ${CMAKE_CURRENT_SOURCE_DIR}/src/common/build_info.cpp
+                OUTPUT_QUIET ERROR_QUIET)
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/common/build_info.cpp.in
-               ${CMAKE_CURRENT_SOURCE_DIR}/src/common/build_info.cpp @ONLY)
+               ${CMAKE_CURRENT_BINARY_DIR}/src/common/build_info.cpp @ONLY)
 
 # Compile source files
 include_directories(${marian_SOURCE_DIR}/src)
diff --git a/cmake/GetVersionFromFile.cmake b/cmake/GetVersionFromFile.cmake
index 29b9d2bca..0e9c54fe8 100644
--- a/cmake/GetVersionFromFile.cmake
+++ b/cmake/GetVersionFromFile.cmake
@@ -18,7 +18,7 @@
 if(PROJECT_VERSION_FILE)
   file(STRINGS ${PROJECT_VERSION_FILE} PROJECT_VERSION_STRING)
 else()
-  file(STRINGS ${CMAKE_SOURCE_DIR}/VERSION PROJECT_VERSION_STRING)
+  file(STRINGS ${CMAKE_CURRENT_SOURCE_DIR}/VERSION PROJECT_VERSION_STRING)
 endif()
 
 # Get current commit SHA from git
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 94dc6a258..bcee1b385 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -20,7 +20,7 @@ add_library(marian STATIC
   common/config_validator.cpp
   common/options.cpp
   common/binary.cpp
-  common/build_info.cpp
+  ${CMAKE_CURRENT_BINARY_DIR}/common/build_info.cpp
   common/io.cpp
   common/filesystem.cpp
   common/file_stream.cpp
@@ -118,21 +118,22 @@ target_compile_options(marian PUBLIC ${ALL_WARNINGS})
 # Git updates .git/logs/HEAD file whenever you pull or commit something.
 
 # If Marian is checked out as a submodule in another repository,
-# there's no .git directory in ${CMAKE_SOURCE_DIR}. Instead .git is a
-# file that specifies the relative path from ${CMAKE_SOURCE_DIR} to
-# ./git/modules/<MARIAN_ROOT_DIR> in the root of the repository that
-# contains Marian as a submodule. We set MARIAN_GIT_DIR to the appropriate
-# path, depending on whether ${CMAKE_SOURCE_DIR}/.git is a directory or file.
-if(IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.git) # not a submodule
-  set(MARIAN_GIT_DIR ${CMAKE_SOURCE_DIR}/.git)
-else(IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.git)
-  file(READ ${CMAKE_SOURCE_DIR}/.git MARIAN_GIT_DIR)
+# ${CMAKE_CURRENT_SOURCE_DIR}/../.git is not a directory but a file
+# that specifies the relative path from ${CMAKE_CURRENT_SOURCE_DIR}/..
+# to ./git/modules/<MARIAN_ROOT_DIR> in the root of the check_out of
+# the project that contains Marian as a submodule.
+#
+# We set MARIAN_GIT_DIR to the appropriate path, depending on whether
+# ${CMAKE_CURRENT_SOURCE_DIR}/../.git is a directory or file.
+set(MARIAN_GIT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../.git)
+if(NOT IS_DIRECTORY ${MARIAN_GIT_DIR}) # i.e., it's a submodule
+  file(READ ${MARIAN_GIT_DIR} MARIAN_GIT_DIR)
   string(REGEX REPLACE "gitdir: (.*)\n" "\\1" MARIAN_GIT_DIR ${MARIAN_GIT_DIR})
-  get_filename_component(MARIAN_GIT_DIR "${CMAKE_SOURCE_DIR}/${MARIAN_GIT_DIR}" ABSOLUTE)
-endif(IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.git)
+  get_filename_component(MARIAN_GIT_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../${MARIAN_GIT_DIR}" ABSOLUTE)
+endif(NOT IS_DIRECTORY ${MARIAN_GIT_DIR})
 
 add_custom_command(OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/common/git_revision.h
-  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
   COMMAND git log -1 --pretty=format:\#define\ GIT_REVISION\ \"\%h\ \%ai\" > ${CMAKE_CURRENT_SOURCE_DIR}/common/git_revision.h
   DEPENDS ${MARIAN_GIT_DIR}/logs/HEAD
   VERBATIM