From edae5f1e75eaa5f8f97753b883ebddd51cb6a111 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@tuebingen.mpg.de>
Date: Sun, 17 May 2020 22:04:40 +0200
Subject: [PATCH] build: Prefix CFLAGS and friends with OSL_.

It is best practice to leave the "official" CPPFLAGS, CFLAGS and
LDFLAGS variables alone and just add them at the end of the command
line options. This way the user may override any of our settings
by setting the corresponding option in the official variable. For
example, to deactivate warnings about unused variables or functions,
one may compile with

	make CFLAGS=-Wno-unused
---
 Makefile | 45 +++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/Makefile b/Makefile
index 8e0f163..61ac1dc 100644
--- a/Makefile
+++ b/Makefile
@@ -28,26 +28,25 @@ y := 1
 z := 3
 VERSION := $(x).$(y).$(z)
 
-# common flags
-CPPFLAGS += -DOSL_VERSION='"$(VERSION)"'
-
-CFLAGS += -Wno-sign-compare -g -Wunused -Wundef -W
-CFLAGS += -Wredundant-decls
-CFLAGS += -Os
-CFLAGS += -Wall
-CFLAGS += -Wuninitialized
-CFLAGS += -Wchar-subscripts
-CFLAGS += -Wformat-security
-CFLAGS += -Werror-implicit-function-declaration
-CFLAGS += -Wmissing-format-attribute
-CFLAGS += -Wunused-macros
-CFLAGS += -Wbad-function-cast
-CFLAGS += -fPIC
-CFLAGS += -fvisibility=hidden
-
-LDFLAGS += -Wl,-soname,$(soname)
-LDFLAGS += -Wl,-z,defs
-LDFLAGS += --shared
+OSL_CPPFLAGS += -DOSL_VERSION='"$(VERSION)"'
+
+OSL_CFLAGS += -Wno-sign-compare -g -Wunused -Wundef -W
+OSL_CFLAGS += -Wredundant-decls
+OSL_CFLAGS += -Os
+OSL_CFLAGS += -Wall
+OSL_CFLAGS += -Wuninitialized
+OSL_CFLAGS += -Wchar-subscripts
+OSL_CFLAGS += -Wformat-security
+OSL_CFLAGS += -Werror-implicit-function-declaration
+OSL_CFLAGS += -Wmissing-format-attribute
+OSL_CFLAGS += -Wunused-macros
+OSL_CFLAGS += -Wbad-function-cast
+OSL_CFLAGS += -fPIC
+OSL_CFLAGS += -fvisibility=hidden
+
+OSL_LDFLAGS += -Wl,-soname,$(soname)
+OSL_LDFLAGS += -Wl,-z,defs
+OSL_LDFLAGS += --shared
 
 # On ELf-based systems, the following conventions apply (see dhweeler's
 # Program Library HOWTO):
@@ -74,7 +73,9 @@ ifeq ($(findstring clean, $(MAKECMDGOALS)),)
 -include $(deps)
 endif
 %.o: %.c Makefile errtab.h
-	$(CC) $(CPPFLAGS) -c -MMD -MF $(*F).d -MT $@ $(CFLAGS) $<
+	$(CC) $(OSL_CPPFLAGS) $(CPPFLAGS) \
+		-c -MMD -MF $(*F).d -MT $@ \
+		$(OSL_CFLAGS) $(CFLAGS) $<
 
 fsck.o: oslfsck.lsg.h
 oslfsck: $(fsck_objects)
@@ -90,7 +91,7 @@ oslfsck: $(fsck_objects)
 	lopsubgen --gen-man=$@ < $<
 
 $(realname): $(objects)
-	$(CC) $(LDFLAGS) -o $@ $(objects)
+	$(CC) $(OSL_LDFLAGS) $(LDFLAGS) -o $@ $(objects)
 
 $(libname).sym: osl.h.in
 	sed -Ene '/^int|^const/{s/.*(osl_.*)\(.*/\1/; p;}' $< > $@
-- 
2.30.2