From b9d2a1268f828f391bc21169bc947c2a53b772d6 Mon Sep 17 00:00:00 2001
From: Guillem Jover <guillem@hadrons.org>
Date: Sun, 12 Apr 2020 04:01:27 +0200
Subject: [PATCH] [PATCH libaio 03/14] build: Honor user build flags
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

CPPFLAGS, CFLAGS and LDFLAGS are user flags, which we need to preserve,
regardless of the user passing them over the environment or the
command-line. Any required flag that the build system needs, has to be
set in some other flag (which we will namespace with «MK_») so that the
build will use even if the user flags are passed, even though the user
should be able to override by appending after them. We pass CPPFLAGS to
any compilation command that missed them.

Signed-off-by: Guillem Jover <guillem@hadrons.org>

Gbp-Pq: Name 0003-build-Honor-user-build-flags.patch
---
 harness/Makefile |  9 ++++++---
 src/Makefile     | 20 ++++++++++----------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/harness/Makefile b/harness/Makefile
index 4f225d3..8cb27fa 100644
--- a/harness/Makefile
+++ b/harness/Makefile
@@ -6,13 +6,16 @@ PROGS:=$(PARTPROGS) $(EXTRAPROGS)
 HARNESS_SRCS:=main.c
 # io_queue.c
 
-CFLAGS+=-Wall -Werror -I../src -g -O2
+MK_CPPFLAGS = -I../src $(CPPFLAGS)
+CFLAGS ?= -Wall -Werror -g -O2
+MK_CFLAGS = $(CFLAGS)
 #-lpthread -lrt
+MK_LDFLAGS = main.c $(LIBAIO) -lpthread $(LDFLAGS)
 
 # gcc-11 does not like the test case in 3.t that
 # passes an invalid pointer (-1) to the kernel, so
 # tell the compiler we do not need a warning here
-cases/3.p:	CFLAGS+=-Wno-stringop-overflow
+cases/3.p:	MK_CFLAGS+=-Wno-stringop-overflow
 
 # Change this on the build line to run tests against the installed libraries:
 # make LIBAIO=-laio partcheck
@@ -21,7 +24,7 @@ LIBAIO?=../src/libaio.a
 all: $(PROGS)
 
 $(PROGS): %.p: %.t $(HARNESS_SRCS)
-	$(CC) $(CFLAGS) -DTEST_NAME=\"$<\" -o $@ main.c $(LIBAIO) -lpthread
+	$(CC) $(MK_CPPFLAGS) $(MK_CFLAGS) -DTEST_NAME=\"$<\" -o $@ $(MK_LDFLAGS)
 
 clean:
 	rm -f $(PROGS) *.o runtests.out rofile wofile rwfile
diff --git a/src/Makefile b/src/Makefile
index 9a36d0d..9a1ba51 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2,12 +2,12 @@ prefix ?= /usr
 includedir ?= $(prefix)/include
 libdir ?= $(prefix)/lib
 
-CFLAGS ?= -g -fomit-frame-pointer -O2
-CFLAGS += -Wall -I. -fPIC
-SO_CFLAGS=-shared $(CFLAGS)
-L_CFLAGS=$(CFLAGS)
-LINK_FLAGS=
-LINK_FLAGS+=$(LDFLAGS)
+MK_CPPFLAGS = -I. $(CPPFLAGS)
+CFLAGS ?= -Wall -g -fomit-frame-pointer -O2
+MK_CFLAGS = -fPIC $(CFLAGS)
+SO_CFLAGS = -shared $(MK_CFLAGS)
+L_CFLAGS = $(MK_CFLAGS)
+MK_LDFLAGS = $(LDFLAGS)
 ENABLE_SHARED ?= 1
 
 soname=libaio.so.1
@@ -42,10 +42,10 @@ libaio_sobjs := $(patsubst %.c,%.os,$(libaio_srcs))
 $(libaio_objs) $(libaio_sobjs): libaio.h vsys_def.h
 
 %.os: %.c
-	$(CC) $(SO_CFLAGS) -c -o $@ $<
+	$(CC) $(MK_CPPFLAGS) $(SO_CFLAGS) -c -o $@ $<
 
 %.ol: %.c
-	$(CC) $(L_CFLAGS) -c -o $@ $<
+	$(CC) $(MK_CPPFLAGS) $(L_CFLAGS) -c -o $@ $<
 
 AR ?= ar
 RANLIB ?= ranlib
@@ -55,8 +55,8 @@ libaio.a: $(libaio_objs)
 	$(RANLIB) libaio.a
 
 $(libname): $(libaio_sobjs) libaio.map
-	$(CC) $(CFLAGS) -c struct_offsets.c
-	$(CC) $(SO_CFLAGS) -Wl,--version-script=libaio.map -Wl,-soname=$(soname) -o $@ $(libaio_sobjs) $(LINK_FLAGS)
+	$(CC) $(MK_CPPFLAGS) $(MK_CFLAGS) -c struct_offsets.c
+	$(CC) $(SO_CFLAGS) -Wl,--version-script=libaio.map -Wl,-soname=$(soname) -o $@ $(libaio_sobjs) $(MK_LDFLAGS)
 
 install: $(all_targets)
 	install -D -m 644 libaio.h $(DESTDIR)$(includedir)/libaio.h
-- 
2.30.2