From d876f6f12b7719a5f477a6ccabb943a32be05755 Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Tue, 12 Jul 2022 18:23:01 -0700
Subject: Include diff and diffstat from git.

---
 Makefile       | 17 +----------------
 git-tag.h      |  2 ++
 main.cpp       |  4 ++++
 tools/mkgit.rb | 28 ++++++++++++++++++++++++++++
 4 files changed, 35 insertions(+), 16 deletions(-)
 create mode 100755 tools/mkgit.rb

diff --git a/Makefile b/Makefile
index 6a9baab..cb8b824 100644
--- a/Makefile
+++ b/Makefile
@@ -14,19 +14,6 @@ CXXFLAGS := -Wall -Werror -std=c++20 -fPIC -iquote . ${PKG_FLAGS} ${OPTIMIZE} ${
 
 .DEFAULT_GOAL := all
 
-VERSION := $(shell git describe --always --dirty --long --tags 2> /dev/null)
-ifndef VERSION
-VERSION := unknown
-endif
-$(info Version ${VERSION})
-
-define GITTAGCPP =
-#include "git-tag.h"
-
-const char *GIT_TAG = "$(subst ",\",${VERSION})";
-endef
-export GITTAGCPP
-
 ifneq ($(shell which ${IWYU}),)
 iwyu = ${CHRONIC} ${IWYU} -Xiwyu --error -Xiwyu --mapping_file=tools/iwyu.imp -Xiwyu --no_fwd_decls ${CXXFLAGS} $(1)
 else
@@ -97,8 +84,6 @@ endif
 MAINOBJS := $(patsubst %.cpp,build/%.o,$(wildcard *.cpp))
 MAINOBJS += build/git-tag.o
 
-$(info )
-
 all: ${IWYU_CPPS} issim issim-static
 
 issim: build/issim-dynamic
@@ -123,7 +108,7 @@ clean:
 
 build/git-tag.cpp:
 	@mkdir -p $(dir $@)
-	@echo "$$GITTAGCPP" > $@
+	@tools/mkgit.rb > $@
 .PHONY: build/git-tag.cpp
 
 build/%.o: %.cpp
diff --git a/git-tag.h b/git-tag.h
index 0f36b73..0e742a5 100644
--- a/git-tag.h
+++ b/git-tag.h
@@ -1,3 +1,5 @@
 #pragma once
 
 extern const char *GIT_TAG;
+extern const char *GIT_DIFF;
+extern const char *GIT_STAT;
diff --git a/main.cpp b/main.cpp
index 7142eed..ffc6cad 100644
--- a/main.cpp
+++ b/main.cpp
@@ -13,6 +13,10 @@
 int main(int argc, const char *argv[])
 {
     std::cout << "Version " << GIT_TAG << "\n";
+    if (GIT_STAT)
+        std::cout << GIT_STAT << "\n";
+    if (GIT_DIFF)
+        std::cout << GIT_DIFF << "\n";
 
     fib::Fib<3> fib;
 
diff --git a/tools/mkgit.rb b/tools/mkgit.rb
new file mode 100755
index 0000000..2a6ef4c
--- /dev/null
+++ b/tools/mkgit.rb
@@ -0,0 +1,28 @@
+#!/usr/bin/ruby -w
+
+$stdout.write(<<END)
+#include "git-tag.h"
+
+END
+
+IO.popen(["git", "describe", "--always", "--dirty", "--long", "--tags"], "r") do | io |
+  $stdout.write("const char *GIT_TAG = #{io.read.strip.dump};\n")
+end
+
+IO.popen(["git", "diff"]) do | io |
+  diff = io.read
+  if diff.strip == ""
+    $stdout.write("const char *GIT_DIFF = nullptr;\n")
+  else
+    $stdout.write("const char *GIT_DIFF = #{diff.dump};\n")
+  end
+end
+
+IO.popen(["git", "diff", "--stat"]) do | io |
+  stat = io.read
+  if stat.strip == ""
+    $stdout.write("const char *GIT_STAT = nullptr;\n")
+  else
+    $stdout.write("const char *GIT_STAT = #{stat.dump};\n")
+  end
+end
-- 
cgit v1.2.3