[OE-core] [PATCH 1/5] base/bbclass: use target path as compile dir in debugging info

[Hongxu Jia]

In debugging information, it uses target paths rather than
build ones as compile dir.
...
 -fdebug-prefix-map=old=new
   When compiling files in directory old, record debugging
   information describing them as in new instead.
...

Compile without this fix:
objdump -g git/test.o
...
 The Directory Table (offset 0x1b):
|  1     /buildarea/raid0/hjia/build-20160119-yocto-buildpath/tmp/sysroots/x86_64-linux/usr/lib/
i686-pokymllib32-linux.lib32-gcc-cross-initial-i686/gcc/i686-pokymllib32-linux/5.3.0/include
|  2     /buildarea/raid0/hjia/build-20160119-yocto-buildpath/tmp/sysroots/lib32-qemux86-64/usr/include/bits
|  3     /buildarea/raid0/hjia/build-20160119-yocto-buildpath/tmp/sysroots/lib32-qemux86-64/usr/include
...

Compile with this fix:
objdump -g git/test.o
...
 The Directory Table (offset 0x1b):
|  1     /usr/lib/i686-pokymllib32-linux.lib32-gcc-cross-initial-i686/gcc/i686-pokymllib32-linux/
5.3.0/include
|  2     /usr/include/bits
|  3     /usr/include
...

[YOCTO #7058]

Signed-off-by: Hongxu Jia <hongxu.jia at windriver.com>
---
 meta/conf/bitbake.conf | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index e80ee18..bebaaf4 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -546,7 +546,14 @@ EXTRA_OEMAKE_prepend_task-install = "${PARALLEL_MAKEINST} "
 ##################################################################
 # Optimization flags.
 ##################################################################
-DEBUG_FLAGS ?= "-g -feliminate-unused-debug-types"
+DEBUG_FLAGS ?= "-g \
+    -feliminate-unused-debug-types \
+    -fdebug-prefix-map=${B}=/usr/src/${BPN} \
+    -fdebug-prefix-map=${S}=/usr/src/${BPN} \
+    -fdebug-prefix-map=${STAGING_DIR_NATIVE}= \
+    -fdebug-prefix-map=${STAGING_DIR_HOST}= \
+"
+
 # Disabled until the option works properly -feliminate-dwarf2-dups
 FULL_OPTIMIZATION = "-O2 -pipe ${DEBUG_FLAGS}"
 DEBUG_OPTIMIZATION = "-O -fno-omit-frame-pointer ${DEBUG_FLAGS} -pipe"
-- 
1.9.1