From 561ec9a7c440f8f15f28c714c3907a443923910c Mon Sep 17 00:00:00 2001
From: Randy Palamar <palamar@ualberta.ca>
Date: Sun, 30 Jul 2023 21:26:01 -0600
Subject: [PATCH] build: add dependency tracking for header files

---
 .gitignore |  1 +
 Makefile   | 13 +++++++++----
 configure  |  2 +-
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7aa3fae06..950e4d84a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@
 *.gcov
 *.html
 *.o
+*.d
diff --git a/Makefile b/Makefile
index 585b826c0..0fd5fa905 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,7 @@ SRC = array.c \
 	vis-text-objects.c \
 	$(REGEX_SRC)
 OBJ = $(SRC:.c=.o)
+DEP = $(OBJ:.o=.d)
 
 ELF = vis vis-menu vis-digraph
 EXECUTABLES = $(ELF) vis-clipboard vis-complete vis-open
@@ -46,7 +47,7 @@ CONFIG_TRE ?= 0
 CONFIG_ACL ?= 0
 CONFIG_SELINUX ?= 0
 
-CFLAGS_STD ?= -std=c99 -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -DNDEBUG
+CFLAGS_STD ?= -std=c99 -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -DNDEBUG -MMD
 CFLAGS_STD += -DVERSION=\"${VERSION}\"
 LDFLAGS_STD ?= -lc
 
@@ -83,9 +84,13 @@ config.h:
 config.mk:
 	@touch $@
 
-$(OBJ): config.mk config.h
+main.o: config.h
 
-vis: config.h config.mk *.h ${OBJ}
+$(OBJ): config.mk
+
+-include $(DEP)
+
+vis: ${OBJ}
 	${CC} -o $@ ${OBJ} ${LDFLAGS} ${LDFLAGS_VIS} ${LDFLAGS_EXTRA}
 
 vis-menu: vis-menu.c
@@ -154,7 +159,7 @@ testclean:
 
 clean:
 	@echo cleaning
-	@rm -f $(ELF) $(OBJ) vis-single vis-single-payload.inc vis-*.tar.gz *.gcov *.gcda *.gcno
+	@rm -f $(ELF) $(OBJ) $(DEP) vis-single vis-single-payload.inc vis-*.tar.gz *.gcov *.gcda *.gcno
 
 distclean: clean testclean
 	@echo cleaning build configuration
diff --git a/configure b/configure
index d71ab78b1..5d7c821bf 100755
--- a/configure
+++ b/configure
@@ -220,7 +220,7 @@ tryflag   CFLAGS_TRY  -Werror=unused-command-line-argument
 tryldflag LDFLAGS_TRY -Werror=unknown-warning-option
 tryldflag LDFLAGS_TRY -Werror=unused-command-line-argument
 
-CFLAGS_STD="-std=c99 -D_POSIX_C_SOURCE=200809L -U_XOPEN_SOURCE -D_XOPEN_SOURCE=700 -DNDEBUG"
+CFLAGS_STD="-std=c99 -D_POSIX_C_SOURCE=200809L -U_XOPEN_SOURCE -D_XOPEN_SOURCE=700 -DNDEBUG -MMD"
 LDFLAGS_STD="-lc"
 
 OS=$(uname)