From bf6a5a643f888decbd9b77900c6ce32a14903c2e Mon Sep 17 00:00:00 2001
From: Matt Penny <mwpenny@users.noreply.github.com>
Date: Mon, 26 Aug 2024 16:36:12 -0400
Subject: [PATCH] Support building from source code archive (#85)

Save git describe output on `git archive` and fall back to saved
output for version number if building outside of a git repo.
---
 .gitattributes |  2 ++
 Makefile       | 11 ++++++++---
 version.txt    |  1 +
 3 files changed, 11 insertions(+), 3 deletions(-)
 create mode 100644 .gitattributes
 create mode 100644 version.txt

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..5f0b44a
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+# Save version on export to support building outside of git repo
+version.txt export-subst
diff --git a/Makefile b/Makefile
index 704c4f6..8bbca3c 100644
--- a/Makefile
+++ b/Makefile
@@ -19,8 +19,12 @@ $(SKELATOOL64):
 
 	@$(MAKE) -C skelatool64
 
-# Use tag name if a tag exists, otherwise use commit hash
-GAME_VERSION		:=  $(shell git describe --tags --exact-match HEAD 2>/dev/null || git rev-parse --short HEAD)
+# Use tag name if the current commit is tagged, otherwise use commit hash
+# If not in a git repo, fall back to exported version
+GAME_VERSION		:=  $(shell \
+	(git describe --tags HEAD 2>/dev/null || cat version.txt) | \
+	awk -F '-' '{print (NF >= 3 ? substr($$3, 2) : $$1)}' \
+)
 
 OPTIMIZER		:= -Os
 LCDEFS			:= -DDEBUG -DGAME_VERSION=\"$(GAME_VERSION)\" -g -Werror -Wall
@@ -142,7 +146,8 @@ buildgame: $(BASE_TARGET_NAME).z64
 .PHONY: gameversion
 build/version.txt: gameversion
 ifneq ($(shell cat build/version.txt 2>/dev/null), $(GAME_VERSION))
-	echo -n $(GAME_VERSION) > build/version.txt
+	@mkdir -p $(@D)
+	@echo -n $(GAME_VERSION) > $@
 endif
 
 include $(COMMONRULES)
diff --git a/version.txt b/version.txt
new file mode 100644
index 0000000..be0bb0a
--- /dev/null
+++ b/version.txt
@@ -0,0 +1 @@
+$Format:%(describe:tags)$
\ No newline at end of file