[Qemu-devel] [PATCH] Use vpath directive

[Paolo Bonzini <pbonzini@redhat.com>]

The vpath directive has two advantages over the VPATH variable:
1) it allows to skip searching of .o files; 2) the default semantics
are to append to the vpath, so there is no confusion between "VPATH=xyz"
and "VPATH+=xyz".

Since "vpath %.c %.h PATH" is not valid, I'm introducing a wrapper
macro to append one or more directories to the vpath.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
	This one also fixes the same race (by building cutils.o twice).
        However, it is nicer in that it fixes the wrong occurrence of
        "vpath %.c %.h PATH" (sorry for missing that on my review of
        Kirill's patch).

 Makefile                   |    2 +-
 Makefile.hw                |    2 +-
 Makefile.target            |   11 +++++++----
 Makefile.user              |    6 +-----
 pc-bios/optionrom/Makefile |    3 ++-
 rules.mak                  |    2 ++
 tests/Makefile             |    3 ++-
 7 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/Makefile b/Makefile
index ec52ee2..645ec82 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ configure: ;
 .PHONY: all clean cscope distclean dvi html info install install-doc \
 	recurse-all speed tar tarbin test build-all
 
-VPATH=$(SRC_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
 
 LIBS+=-lz $(LIBS_TOOLS)
 
diff --git a/Makefile.hw b/Makefile.hw
index bd252f5..781c006 100644
--- a/Makefile.hw
+++ b/Makefile.hw
@@ -7,7 +7,7 @@ include $(SRC_PATH)/rules.mak
 
 .PHONY: all
 
-VPATH=$(SRC_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
 
 QEMU_CFLAGS+=-I.. -I$(SRC_PATH)/fpu
 
diff --git a/Makefile.target b/Makefile.target
index 0504d3b..92c2027 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -9,7 +9,7 @@ include config-target.mak
 include $(SRC_PATH)/rules.mak
 
 TARGET_PATH=$(SRC_PATH)/target-$(TARGET_BASE_ARCH)
-VPATH=$(SRC_PATH):$(TARGET_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(TARGET_PATH):$(SRC_PATH)/hw)
 QEMU_CFLAGS+= -I.. -I$(TARGET_PATH) -DNEED_CPU_H
 
 ifdef CONFIG_USER_ONLY
@@ -87,7 +87,8 @@ signal.o: QEMU_CFLAGS += $(HELPER_CFLAGS)
 
 ifdef CONFIG_LINUX_USER
 
-VPATH+=:$(SRC_PATH)/linux-user:$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR)
+$(call set-vpath, $(SRC_PATH)/linux-user:$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR))
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user -I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR)
 obj-y = main.o syscall.o strace.o mmap.o signal.o thunk.o \
       elfload.o linuxload.o uaccess.o gdbstub.o
@@ -115,7 +116,8 @@ endif #CONFIG_LINUX_USER
 
 ifdef CONFIG_DARWIN_USER
 
-VPATH+=:$(SRC_PATH)/darwin-user
+$(call set-vpath, $(SRC_PATH)/darwin-user)
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/darwin-user -I$(SRC_PATH)/darwin-user/$(TARGET_ARCH)
 
 # Leave some space for the regular program loading zone
@@ -137,7 +139,8 @@ endif #CONFIG_DARWIN_USER
 
 ifdef CONFIG_BSD_USER
 
-VPATH+=:$(SRC_PATH)/bsd-user
+$(call set-vpath, $(SRC_PATH)/bsd-user)
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/bsd-user -I$(SRC_PATH)/bsd-user/$(TARGET_ARCH)
 
 obj-y = main.o bsdload.o elfload.o mmap.o signal.o strace.o syscall.o \
diff --git a/Makefile.user b/Makefile.user
index 7daedef..5df114f 100644
--- a/Makefile.user
+++ b/Makefile.user
@@ -6,11 +6,7 @@ include $(SRC_PATH)/rules.mak
 
 .PHONY: all
 
-# Do not take %.o from $(SRC_PATH), only %.c and %.h
-# All %.o for user targets should be built with -fpie, when
-# configured with --enable-user-pie, so we don't want to
-# take %.o from $(SRC_PATH), since they built without -fpie
-vpath %.c %.h $(SRC_PATH)
+$(call set-vpath, $(SRC_PATH))
 
 QEMU_CFLAGS+=-I..
 
diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
index 54db882..b4be31e 100644
--- a/pc-bios/optionrom/Makefile
+++ b/pc-bios/optionrom/Makefile
@@ -5,7 +5,8 @@ all: build-all
 include ../../config-host.mak
 include $(SRC_PATH)/rules.mak
 
-VPATH=$(SRC_PATH)/pc-bios/optionrom
+$(call set-vpath, $(SRC_PATH)/pc-bios/optionrom)
+
 .PHONY : all clean build-all
 
 CFLAGS := -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin
diff --git a/rules.mak b/rules.mak
index 5d9f684..9cd67f0 100644
--- a/rules.mak
+++ b/rules.mak
@@ -39,6 +39,8 @@ quiet-command = $(if $(V),$1,$(if $(2),@echo $2 && $1, @$1))
 cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
               >/dev/null 2>&1 && echo OK), $2, $3)
 
+set-vpath = $(if $1,$(foreach PATTERN,%.c %.h %.S, $(eval vpath $(PATTERN) $1)))
+
 # Generate timestamp files for .h include files
 
 %.h: %.h-timestamp
diff --git a/tests/Makefile b/tests/Makefile
index 69092e5..ff7f787 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -1,5 +1,6 @@
 -include ../config-host.mak
-VPATH=$(SRC_PATH)/tests
+
+$(call set-vpath, $(SRC_PATH)/tests)
 
 CFLAGS=-Wall -O2 -g -fno-strict-aliasing
 #CFLAGS+=-msse2
-- 
1.6.5.2