[Buildroot] [PATCH v4] toolchain-external: Fix EABIhf check

[Buildroot] [PATCH v4] toolchain-external: Fix EABIhf check

[Thomas De Schampheleire]

From: Stefan S?rensen <stefan.sorensen@spectralink.com>

Currently the check for EABI/EABIhf toolchains looks for the
Tag_ABI_VFP_args attribute in the crt1.o file which gcc adds in an
EABIhf toolchain.
In uClibc, however, crt1.o is not compiled from c but assembly, so the
Tag_ABI_VFP_args attribute is not added in the object file. This causes
the EABIhf check in the external toolchain logic to fail for
uClibc-based toolchains.

Fix by compiling a dummy .c file and trying to link the object against the
C library. Since it is impossible to mix EABI and EABIhf code, a mismatch
between the buildroot and toolchain ABI settings will be detected during
this link step.

Fixes bug #6842: https://bugs.busybox.net/show_bug.cgi?id=6842

Signed-off-by: Stefan S?rensen <stefan.sorensen@spectralink.com>
[ThomasDS: do full link iso readelf test, update commit message]
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

---
Note: this v4 did not change the error message, awaiting Arnout's input.

v4: (ThomasDS)
  - avoid creating a temporary object file (Arnout)

v3: (ThomasDS)
  - v2 properly recognized a uClibc EABIhf toolchain, but failed to detect a
    mismatch with buildroot settings (detected by ThomasP). Fix by
    performing an actual link step to detect any incompatibility.
v2: (ThomasDS)
  - avoid creating a temporary source file
  - update commit message

 toolchain/helpers.mk |  16 ++++------------
 1 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
--- a/toolchain/helpers.mk
+++ b/toolchain/helpers.mk
@@ -297,20 +297,12 @@ check_arm_abi = \
 		echo "External toolchain uses the unsuported OABI" ; \
 		exit 1 ; \
 	fi ; \
-	EXT_TOOLCHAIN_CRT1=`LANG=C $${__CROSS_CC} -print-file-name=crt1.o` ; \
-	if $${__CROSS_READELF} -A $${EXT_TOOLCHAIN_CRT1} | grep -q "Tag_ABI_VFP_args:" ; then \
-		EXT_TOOLCHAIN_ABI="eabihf" ; \
-	else \
-		EXT_TOOLCHAIN_ABI="eabi" ; \
-	fi ; \
-	if [ "$(BR2_ARM_EABI)" = "y" -a "$${EXT_TOOLCHAIN_ABI}" = "eabihf" ] ; then \
-		echo "Incorrect ABI setting: EABI selected, but toolchain uses EABIhf" ; \
+	if ! echo 'int main(void) {}' | $${__CROSS_CC} -x c -o /dev/null - 2>/dev/null; then \
+		abistr_$(BR2_ARM_EABI)='EABI'; \
+		abistr_$(BR2_ARM_EABIHF)='EABIhf'; \
+		echo "Incorrect ABI setting: $${abistr_y} selected, but toolchain is incompatible"; \
 		exit 1 ; \
 	fi ; \
-	if [ "$(BR2_ARM_EABIHF)" = "y" -a "$${EXT_TOOLCHAIN_ABI}" = "eabi" ] ; then \
-		echo "Incorrect ABI setting: EABIhf selected, but toolchain uses EABI" ; \
-		exit 1 ; \
-	fi
 
 #
 # Check that the external toolchain supports C++

[Buildroot] [PATCH v4] toolchain-external: Fix EABIhf check

[Arnout Vandecappelle]

On 09/05/14 13:44, Thomas De Schampheleire wrote:
> From: Stefan S?rensen <stefan.sorensen@spectralink.com>
> 
> Currently the check for EABI/EABIhf toolchains looks for the
> Tag_ABI_VFP_args attribute in the crt1.o file which gcc adds in an
> EABIhf toolchain.
> In uClibc, however, crt1.o is not compiled from c but assembly, so the
> Tag_ABI_VFP_args attribute is not added in the object file. This causes
> the EABIhf check in the external toolchain logic to fail for
> uClibc-based toolchains.
> 
> Fix by compiling a dummy .c file and trying to link the object against the
> C library. Since it is impossible to mix EABI and EABIhf code, a mismatch
> between the buildroot and toolchain ABI settings will be detected during
> this link step.
> 
> Fixes bug #6842: https://bugs.busybox.net/show_bug.cgi?id=6842
> 
> Signed-off-by: Stefan S?rensen <stefan.sorensen@spectralink.com>
> [ThomasDS: do full link iso readelf test, update commit message]
> Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

[snip]

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F

[Buildroot] [PATCH v4] toolchain-external: Fix EABIhf check

[Peter Korsgaard]

>>>>> "Thomas" == Thomas De Schampheleire <patrickdepinguin@gmail.com> writes:

 > From: Stefan S?rensen <stefan.sorensen@spectralink.com>
 > Currently the check for EABI/EABIhf toolchains looks for the
 > Tag_ABI_VFP_args attribute in the crt1.o file which gcc adds in an
 > EABIhf toolchain.
 > In uClibc, however, crt1.o is not compiled from c but assembly, so the
 > Tag_ABI_VFP_args attribute is not added in the object file. This causes
 > the EABIhf check in the external toolchain logic to fail for
 > uClibc-based toolchains.

 > Fix by compiling a dummy .c file and trying to link the object against the
 > C library. Since it is impossible to mix EABI and EABIhf code, a mismatch
 > between the buildroot and toolchain ABI settings will be detected during
 > this link step.

 > Fixes bug #6842: https://bugs.busybox.net/show_bug.cgi?id=6842

 > Signed-off-by: Stefan S?rensen <stefan.sorensen@spectralink.com>
 > [ThomasDS: do full link iso readelf test, update commit message]
 > Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

 > ---
 > Note: this v4 did not change the error message, awaiting Arnout's input.

 > v4: (ThomasDS)
 >   - avoid creating a temporary object file (Arnout)

 > v3: (ThomasDS)
 >   - v2 properly recognized a uClibc EABIhf toolchain, but failed to detect a
 >     mismatch with buildroot settings (detected by ThomasP). Fix by
 >     performing an actual link step to detect any incompatibility.
 > v2: (ThomasDS)
 >   - avoid creating a temporary source file
 >   - update commit message

 >  toolchain/helpers.mk |  16 ++++------------
 >  1 files changed, 4 insertions(+), 12 deletions(-)

 > diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
 > --- a/toolchain/helpers.mk
 > +++ b/toolchain/helpers.mk
 > @@ -297,20 +297,12 @@ check_arm_abi = \
 >  		echo "External toolchain uses the unsuported OABI" ; \
 >  		exit 1 ; \
 >  	fi ; \
 > -	EXT_TOOLCHAIN_CRT1=`LANG=C $${__CROSS_CC} -print-file-name=crt1.o` ; \
 > -	if $${__CROSS_READELF} -A $${EXT_TOOLCHAIN_CRT1} | grep -q "Tag_ABI_VFP_args:" ; then \
 > -		EXT_TOOLCHAIN_ABI="eabihf" ; \
 > -	else \
 > -		EXT_TOOLCHAIN_ABI="eabi" ; \
 > -	fi ; \
 > -	if [ "$(BR2_ARM_EABI)" = "y" -a "$${EXT_TOOLCHAIN_ABI}" = "eabihf" ] ; then \
 > -		echo "Incorrect ABI setting: EABI selected, but toolchain uses EABIhf" ; \
 > +	if ! echo 'int main(void) {}' | $${__CROSS_CC} -x c -o /dev/null - 2>/dev/null; then \
 > +		abistr_$(BR2_ARM_EABI)='EABI'; \
 > +		abistr_$(BR2_ARM_EABIHF)='EABIhf'; \
 > +		echo "Incorrect ABI setting: $${abistr_y} selected, but toolchain is incompatible"; \
 >  		exit 1 ; \
 >  	fi ; \

This final line should just be 'fi' otherwise the shell gets confused
and I get:

>>> toolchain-external undefined Configuring
/bin/bash: -c: line 0: syntax error near unexpected token `;'

Committed with that fixed, thanks.


 > -	if [ "$(BR2_ARM_EABIHF)" = "y" -a "$${EXT_TOOLCHAIN_ABI}" = "eabi" ] ; then \
 > -		echo "Incorrect ABI setting: EABIhf selected, but toolchain uses EABI" ; \
 > -		exit 1 ; \
 > -	fi

-- 
Bye, Peter Korsgaard

[Buildroot] [PATCH v4] toolchain-external: Fix EABIhf check

[Thomas De Schampheleire]

Peter Korsgaard <jacmet@uclibc.org> schreef:
>>>>>> "Thomas" == Thomas De Schampheleire <patrickdepinguin@gmail.com> writes:
>
> > From: Stefan S?rensen <stefan.sorensen@spectralink.com>
> > Currently the check for EABI/EABIhf toolchains looks for the
> > Tag_ABI_VFP_args attribute in the crt1.o file which gcc adds in an
> > EABIhf toolchain.
> > In uClibc, however, crt1.o is not compiled from c but assembly, so the
> > Tag_ABI_VFP_args attribute is not added in the object file. This causes
> > the EABIhf check in the external toolchain logic to fail for
> > uClibc-based toolchains.
>
> > Fix by compiling a dummy .c file and trying to link the object against the
> > C library. Since it is impossible to mix EABI and EABIhf code, a mismatch
> > between the buildroot and toolchain ABI settings will be detected during
> > this link step.
>
> > Fixes bug #6842: https://bugs.busybox.net/show_bug.cgi?id=6842
>
> > Signed-off-by: Stefan S?rensen <stefan.sorensen@spectralink.com>
> > [ThomasDS: do full link iso readelf test, update commit message]
> > Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
>
> > ---
> > Note: this v4 did not change the error message, awaiting Arnout's input.
>
> > v4: (ThomasDS)
> >   - avoid creating a temporary object file (Arnout)
>
> > v3: (ThomasDS)
> >   - v2 properly recognized a uClibc EABIhf toolchain, but failed to detect a
> >     mismatch with buildroot settings (detected by ThomasP). Fix by
> >     performing an actual link step to detect any incompatibility.
> > v2: (ThomasDS)
> >   - avoid creating a temporary source file
> >   - update commit message
>
> >  toolchain/helpers.mk |  16 ++++------------
> >  1 files changed, 4 insertions(+), 12 deletions(-)
>
> > diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
> > --- a/toolchain/helpers.mk
> > +++ b/toolchain/helpers.mk
> > @@ -297,20 +297,12 @@ check_arm_abi = \
> >  		echo "External toolchain uses the unsuported OABI" ; \
> >  		exit 1 ; \
> >  	fi ; \
> > -	EXT_TOOLCHAIN_CRT1=`LANG=C $${__CROSS_CC} -print-file-name=crt1.o` ; \
> > -	if $${__CROSS_READELF} -A $${EXT_TOOLCHAIN_CRT1} | grep -q "Tag_ABI_VFP_args:" ; then \
> > -		EXT_TOOLCHAIN_ABI="eabihf" ; \
> > -	else \
> > -		EXT_TOOLCHAIN_ABI="eabi" ; \
> > -	fi ; \
> > -	if [ "$(BR2_ARM_EABI)" = "y" -a "$${EXT_TOOLCHAIN_ABI}" = "eabihf" ] ; then \
> > -		echo "Incorrect ABI setting: EABI selected, but toolchain uses EABIhf" ; \
> > +	if ! echo 'int main(void) {}' | $${__CROSS_CC} -x c -o /dev/null - 2>/dev/null; then \
> > +		abistr_$(BR2_ARM_EABI)='EABI'; \
> > +		abistr_$(BR2_ARM_EABIHF)='EABIhf'; \
> > +		echo "Incorrect ABI setting: $${abistr_y} selected, but toolchain is incompatible"; \
> >  		exit 1 ; \
> >  	fi ; \
>
>This final line should just be 'fi' otherwise the shell gets confused
>and I get:
>
>>>> toolchain-external undefined Configuring
>/bin/bash: -c: line 0: syntax error near unexpected token `;'
>
>Committed with that fixed, thanks.

Aargh, that's entirely my fault due to removing the temporary file in v4 and not retesting, sorry.

Best regards,
Thomas