Re: [PATCH 0/4] base/bbclass: use target path to replace build ones in debugging info

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2016-01-29 at 11:39 +0800, Hongxu Jia wrote:
> On 01/29/2016 01:04 AM, Richard Purdie wrote:
> > On Thu, 2016-01-28 at 10:58 +0800, Hongxu Jia wrote:
> > > On 01/28/2016 06:13 AM, Richard Purdie wrote:
> > > > On Wed, 2016-01-27 at 14:34 -0500, Khem Raj wrote:
> > > > > > On Jan 27, 2016, at 5:16 AM, Richard Purdie <
> > > > > > richard.purdie@linuxfoundation.org> wrote:
> > > > > > 
> > > > > > I like the idea of this a lot, I think it makes sense
> > > > > > however
> > > > > > why
> > > > > > not
> > > My original trying was just added them here, but the variable
> > > parsing
> > > at here is too early, the ${BPN}, ${B} and {S} was assigned with
> > > 'defaultpkgname' at this time. Which we have:
> > > ...
> > > > -fdebug-prefix-map=/buildarea/raid0/hjia/build-20160127-yocto
> > > > -buildpath-2/
> > > tmp/work/core2-64-poky-linux/defaultpkgname/1.0-r0/defaultpkgname
> > > -1.0=
> > > /usr/src/defaultpkgname
> > 
> > I think this is just from your debugging technique. By the time
> > these
> > are used in recipes, they will have the correct value for these
> > variables. Expansion happens late, not when the line is parsed.
> 
> For var DEBUG_FLAGS, it indeed has correct value at last, but the
> CFLAGS
> and TARGET_CFLAGS was expanded when DEBUG_FLAGS has 'defaultpkgname'
> 
> The CFLAGS and TARGET_CFLAGS is shell variables (export CFLAGS=), it
> seems shell variable is expanded only once.
> 
> > 
> > Can you be more specific about how you tested this and the problem
> > you
> > saw?
> 
> 1. Modify bitbake.conf
> diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
> index e80ee18..3ddb9e8 100644
> --- a/meta/conf/bitbake.conf
> +++ b/meta/conf/bitbake.conf
> @@ -546,7 +546,14 @@ EXTRA_OEMAKE_prepend_task-install = 
> "${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} \
> +    -gno-record-gcc-switches \
> +    -fdebug-prefix-map=${STAGING_DIR_NATIVE}= \
> +    -fdebug-prefix-map=${STAGING_DIR_HOST}= \
> +"
> 
> 2. Build lib32-glibc, there are still buildpath QA Warnings

I investigated this a little. When I tried your patch I saw:

$ bitbake glibc -e | grep TARGET_CFLAGS=
export TARGET_CFLAGS="
-I/media/build1/poky/build/tmp5/sysroots/qemux86/usr/include -O2 -pipe 
-g -feliminate-unused-debug-types -fdebug-prefix
-map=/media/build1/poky/build/tmp5/work/i586-poky
-linux/defaultpkgname/1.0-r0/defaultpkgname-1.0=/usr/src/defaultpkgname
-fdebug-prefix-map=/media/build1/poky/build/tmp5/work/i586-poky
-linux/defaultpkgname/1.0-r0/defaultpkgname-1.0=/usr/src/defaultpkgname
-gno-record-gcc-switches -fdebug-prefix
-map=/media/build1/poky/build/tmp5/sysroots/x86_64-linux= -fdebug
-prefix-map=/media/build1/poky/build/tmp5/sysroots/qemux86= "

and then once I commented out:

SELECTED_OPTIMIZATION := "${@get_optimization(d)}"

in glibc.inc I see:

$ bitbake glibc -e | grep TARGET_CFLAGS=
export TARGET_CFLAGS="
-I/media/build1/poky/build/tmp5/sysroots/qemux86/usr/include -O2 -pipe 
-g -feliminate-unused-debug-types -fdebug-prefix
-map=/media/build1/poky/build/tmp5/work/i586-poky-linux/glibc/2.22
-r0/build-i586-poky-linux=/usr/src/glibc -fdebug-prefix
-map=/media/build1/poky/build/tmp5/work/i586-poky-linux/glibc/2.22
-r0/git=/usr/src/glibc -gno-record-gcc-switches -fdebug-prefix
-map=/media/build1/poky/build/tmp5/sysroots/x86_64-linux= -fdebug
-prefix-map=/media/build1/poky/build/tmp5/sysroots/qemux86= "

I'd much prefer to fix glibc.inc and put the entries in bitbake.conf
than further complicate the variables unnecessarily.

For example, we could do:

diff --git a/meta/recipes-core/glibc/glibc.inc b/meta/recipes-core/glibc/glibc.inc
index 17fa2d5..8e62b3a 100644
--- a/meta/recipes-core/glibc/glibc.inc
+++ b/meta/recipes-core/glibc/glibc.inc
@@ -10,25 +10,20 @@ TOOLCHAIN_OPTIONS = " --sysroot=${STAGING_DIR_TCBOOTSTRAP}"
 
 # glibc can't be built without optimization, if someone tries to compile an
 # entire image as -O0, we override it with -O2 here and give a note about it.
-def get_optimization(d):
+python () {
     selected_optimization = d.getVar("SELECTED_OPTIMIZATION", True)
-    if bb.utils.contains("SELECTED_OPTIMIZATION", "-O2", "x", "", d) == "x":
-        return selected_optimization
-    elif bb.utils.contains("SELECTED_OPTIMIZATION", "-O", "x", "", d) == "x":
+    if bb.utils.contains("SELECTED_OPTIMIZATION", "-O", "x", "", d) == "x":
         bb.note("glibc can't be built with -O, -O -Wno-error will be used instead.")
-        return selected_optimization.replace("-O", "-O -Wno-error")
+        d.appendVar("SELECTED_OPTIMIZATION", " -Wno-error")
     elif bb.utils.contains("SELECTED_OPTIMIZATION", "-O0", "x", "", d) == "x":
-        bb.note("glibc can't be built with -O0, -O2 will be used instead.")
-        return selected_optimization.replace("-O0", "-O2")
+        bb.fatal("glibc can't be built with -O0, using -O1 -Wno-error or -O1 instead.")
     elif bb.utils.contains("SELECTED_OPTIMIZATION", "-Os", "x", "", d) == "x":
         bb.note("glibc can't be built with -Os, -Os -Wno-error will be used instead.")
-        return selected_optimization.replace("-Os", "-Os -Wno-error")
+        d.appendVar("SELECTED_OPTIMIZATION", " -Wno-error")
     elif bb.utils.contains("SELECTED_OPTIMIZATION", "-O1", "x", "", d) == "x":
         bb.note("glibc can't be built with -O1, -O1 -Wno-error will be used instead.")
-        return selected_optimization.replace("-O1", "-O1 -Wno-error")
-    return selected_optimization
-
-SELECTED_OPTIMIZATION := "${@get_optimization(d)}"
+        d.appendVar("SELECTED_OPTIMIZATION", " -Wno-error")
+}
 
 # siteconfig.bbclass runs configure which needs a working compiler
 # For the compiler to work we need a working libc yet libc isn't

which will now give an error for -O0 but I think that is reasonable.
I'd even prefer to drop the above entirely and use bitbake.conf to be
honest but I know some people insisted we should have the above.

Cheers,

Richard