From 861b55d7d8939d4c4560c1a2d6bcdccad2ac1509 Mon Sep 17 00:00:00 2001
From: ridiculousfish <corydoras@ridiculousfish.com>
Date: Wed, 4 Oct 2017 21:28:55 -0700
Subject: [PATCH] Build FISH-BUILD-VERSION-FILE in CMake build

This adds support for creating the FISH-BUILD-VERSION-FILE in the CMake
build. A FISH-BUILD-VERSION-FILE is created in the CMake directory
and only updated when necessary.
---
 CMakeLists.txt                 | 12 +++++++-----
 build_tools/git_version_gen.sh | 13 ++++++++-----
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 896f6a9fb..5678450c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,11 +30,13 @@ SET(FISH_SRCS
     src/wgetopt.cpp src/wildcard.cpp src/wutil.cpp
 )
 
-# Set up FISH-BUILD-VERSION-FILE
-# Note this happens when CMake runs, not when the generated build system runs
-EXECUTE_PROCESS(COMMAND build_tools/git_version_gen.sh
-                WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-                OUTPUT_QUIET)
+# Set up the version target.
+# This creates the file FISH-BUILD-VERSION-FILE which is only modified if necessary.
+ADD_CUSTOM_COMMAND(OUTPUT "FISH-BUILD-VERSION-FILE"
+                   DEPENDS CHECK-FISH-BUILD-VERSION-FILE)
+
+ADD_CUSTOM_TARGET("CHECK-FISH-BUILD-VERSION-FILE"
+                  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/build_tools/git_version_gen.sh)
 
 # Set up config.h
 INCLUDE(CMakeFiles/ConfigureChecks.cmake)
diff --git a/build_tools/git_version_gen.sh b/build_tools/git_version_gen.sh
index ac3c26186..791ac8ff7 100755
--- a/build_tools/git_version_gen.sh
+++ b/build_tools/git_version_gen.sh
@@ -1,9 +1,12 @@
-#!/bin/sh
+#!/bin/bash
 # Originally from the git sources (GIT-VERSION-GEN)
 # Presumably (C) Junio C Hamano <junkio@cox.net>
 # Reused under GPL v2.0
 # Modified for fish by David Adam <zanchey@ucc.gu.uwa.edu.au>
 
+# Find the fish git directory as two levels up from this directory.
+GIT_DIR=$(dirname $(dirname "${BASH_SOURCE[0]}"))
+
 FBVF=FISH-BUILD-VERSION-FILE
 DEF_VER=unknown
 
@@ -12,17 +15,17 @@ DEF_VER=unknown
 if test -f version
 then
 	VN=$(cat version) || VN="$DEF_VER"
-elif ! VN=$(git describe --always --dirty 2>/dev/null); then
+elif ! VN=$(git -C "$GIT_DIR" describe --always --dirty 2>/dev/null); then
 	VN="$DEF_VER"
 fi
 
 if test -r $FBVF
 then
-	VC=$(sed -e 's/^FISH_BUILD_VERSION = //' <$FBVF)
+	VC=$(sed -e 's/^FISH_BUILD_VERSION=//' <$FBVF)
 else
 	VC=unset
 fi
 test "$VN" = "$VC" || {
-	echo >&2 "FISH_BUILD_VERSION = $VN"
-	echo "FISH_BUILD_VERSION = $VN" >$FBVF
+	echo >&2 "FISH_BUILD_VERSION=$VN"
+	echo "FISH_BUILD_VERSION=$VN" >$FBVF
 }