From 064963bd2702509afee2d2a4ed4eb4b4fd69d9c7 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Mon, 28 Dec 2015 22:00:39 +0100
Subject: [PATCH] build: make out-of-tree builds bit-identical to in-tree
 builds

Previously the full source path was embedded inconsistently in the debug
information between in-tree/out-of-tree builds.

The 'vpath %.inc' becomes necessary for finding
libavfilter/all_channel_layouts.inc in out-of-tree builds.

The full source path is still embedded in the debug information, but
it's now independent of whether building in-tree or out-of-tree.

The biggest improvement of this patch is that gdb now always searches
for the path relative to the source directory. It still also searches
for the full path.
Previously it searched only for the full path in out-of-tree builds,
making the debug information generated by Debian's buildds rather hard
to use.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
---
 Makefile    | 1 +
 common.mak  | 6 +++---
 configure   | 1 +
 library.mak | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 7836a20f87..f3bd5f682d 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,7 @@ include config.mak
 vpath %.c    $(SRC_PATH)
 vpath %.cpp  $(SRC_PATH)
 vpath %.h    $(SRC_PATH)
+vpath %.inc  $(SRC_PATH)
 vpath %.m    $(SRC_PATH)
 vpath %.S    $(SRC_PATH)
 vpath %.asm  $(SRC_PATH)
diff --git a/common.mak b/common.mak
index c3a8b93095..bad262747d 100644
--- a/common.mak
+++ b/common.mak
@@ -32,7 +32,7 @@ endif
 ALLFFLIBS = avcodec avdevice avfilter avformat avresample avutil postproc swscale swresample
 
 # NASM requires -I path terminated with /
-IFLAGS     := -I. -I$(SRC_PATH)/
+IFLAGS     := -I$(DST_PATH)/ -I$(SRC_PATH)/
 CPPFLAGS   := $(IFLAGS) $(CPPFLAGS)
 CFLAGS     += $(ECFLAGS)
 CCFLAGS     = $(CPPFLAGS) $(CFLAGS)
@@ -43,11 +43,11 @@ CXXFLAGS   += $(CPPFLAGS) $(CFLAGS)
 YASMFLAGS  += $(IFLAGS:%=%/) -Pconfig.asm
 
 HOSTCCFLAGS = $(IFLAGS) $(HOSTCPPFLAGS) $(HOSTCFLAGS)
-LDFLAGS    := $(ALLFFLIBS:%=$(LD_PATH)lib%) $(LDFLAGS)
+LDFLAGS    := $(ALLFFLIBS:%=$(LD_PATH)$(DST_PATH)/lib%) $(LDFLAGS)
 
 define COMPILE
        $(call $(1)DEP,$(1))
-       $($(1)) $($(1)FLAGS) $($(1)_DEPFLAGS) $($(1)_C) $($(1)_O) $<
+       $(Q)cd $(SRC_PATH); $(subst @,,$($(1))) $($(1)FLAGS) $($(1)_DEPFLAGS:$(@:.o=.d)=$(DST_PATH)/$(@:.o=.d)) $($(1)_C) $($(1)_O:$@=$(DST_PATH)/$@) $(subst $(SRC_PATH)/,,$<)
 endef
 
 COMPILE_C = $(call COMPILE,CC)
diff --git a/configure b/configure
index ef5a71289c..8f4642b898 100755
--- a/configure
+++ b/configure
@@ -6251,6 +6251,7 @@ SRC_PATH=$source_path
 ifndef MAIN_MAKEFILE
 SRC_PATH:=\$(SRC_PATH:.%=..%)
 endif
+DST_PATH=$(pwd)
 CC_IDENT=$cc_ident
 ARCH=$arch
 INTRINSICS=$intrinsics
diff --git a/library.mak b/library.mak
index 6f95f63410..0b23a28f5b 100644
--- a/library.mak
+++ b/library.mak
@@ -28,7 +28,7 @@ $(SUBDIR)x86/%$(DEFAULT_YASMD).asm: $(SUBDIR)x86/%.asm
 
 $(SUBDIR)x86/%.o: $(SUBDIR)x86/%$(YASMD).asm
 	$(DEPYASM) $(YASMFLAGS) -I $(<D)/ -M -o $@ $< > $(@:.o=.d)
-	$(YASM) $(YASMFLAGS) -I $(<D)/ -o $@ $<
+	$(Q)cd $(SRC_PATH); $(subst @,,$(YASM)) $(YASMFLAGS) -I $(<D)/ -o $(DST_PATH)/$@ $(subst $(SRC_PATH)/,,$<)
 	-$(if $(ASMSTRIPFLAGS), $(STRIP) $(ASMSTRIPFLAGS) $@)
 
 LIBOBJS := $(OBJS) $(SUBDIR)%.h.o $(TESTOBJS)