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toolchain-external: improve musl external check

PATCH New Ilya Kuzmich 2 participants 6 messages Mar 20, 2017 – Apr 3, 2017

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Ilya Kuzmich

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#0 lore raw

PATCH 1/1 toolchain-external: improve musl external check

Test whether musl used or not: compile minimal C program and check if interpreter contains /lib/ld-musl.

Signed-off-by Ilya Kuzmich <[email protected]>
---
 toolchain/helpers.mk                                   | 13 +++++++++----
 toolchain/toolchain-external/pkg-toolchain-external.mk |  4 +++-
 2 files changed, 12 insertions(+), 5 deletions(-)
toolchain/helpers.mk +9 -4
index 2f73ebb..77303a8 100644
@@ -197,13 +197,18 @@ check_glibc = \
 #
 # Check that the selected C library really is musl
 #
-# $1: sysroot directory
+# $1: cross-gcc path
+# $2: cross-readelf path
 check_musl = \
-	SYSROOT_DIR="$(strip $1)"; \
-	if test ! -f $${SYSROOT_DIR}/lib/libc.so -o -e $${SYSROOT_DIR}/lib/libm.so ; then \
+	__CROSS_CC=$(strip $1) ; \
+	__CROSS_READELF=$(strip $2) ; \
+	echo 'void main(void) {}' | $${__CROSS_CC} -x c -o $(BUILD_DIR)/.br-toolchain-test.tmp - >/dev/null 2>&1; \
+	if ! $${__CROSS_READELF} -l $(BUILD_DIR)/.br-toolchain-test.tmp 2> /dev/null | grep 'program interpreter: /lib/ld-musl' -q; then \
+		rm -f $(BUILD_DIR)/.br-toolchain-test.tmp*; \
 		echo "Incorrect selection of the C library" ; \
 		exit -1; \
-	fi
+	fi ; \
+	rm -f $(BUILD_DIR)/.br-toolchain-test.tmp*
 
 #
 # Check the conformity of Buildroot configuration with regard to the
toolchain/toolchain-external/pkg-toolchain-external.mk +3 -1
index 77b7bbb..8a774eb 100644
@@ -565,7 +565,9 @@ define $(2)_CONFIGURE_CMDS
 	if test "$$(BR2_TOOLCHAIN_EXTERNAL_UCLIBC)" = "y" ; then \
 		$$(call check_uclibc,$$$${SYSROOT_DIR}) ; \
 	elif test "$$(BR2_TOOLCHAIN_EXTERNAL_MUSL)" = "y" ; then \
-		$$(call check_musl,$$$${SYSROOT_DIR}) ; \
+		$$(call check_musl,\
+			"$$(TOOLCHAIN_EXTERNAL_CC) $$(TOOLCHAIN_EXTERNAL_CFLAGS)",\
+			$$(TOOLCHAIN_EXTERNAL_READELF)) ; \
 	else \
 		$$(call check_glibc,$$$${SYSROOT_DIR}) ; \
 	fi
Signature · 1 line
2.7.4
#1 lore raw

PATCH 1/1 toolchain-external: improve musl external check

Hello,

Quoted 4 lines · Ilya Kuzmich

Test whether musl used or not: compile minimal C program and check if interpreter contains /lib/ld-musl.

Signed-off-by Ilya Kuzmich <[email protected]>

This doesn't look bad, but what is the motivation behind the change? Is the current check not working for you?

Thanks!

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
author
#2 lore raw

PATCH 1/1 toolchain-external: improve musl external check

Current check fails on crosstool-ng musl toolchain, ctng puts libc.so at sysroot/usr/lib/, not sysroot/lib

Quoted 18 lines · Thomas Petazzoni

Hello,

Quoted 4 lines · Ilya Kuzmich

Test whether musl used or not: compile minimal C program and check if interpreter contains /lib/ld-musl.

Signed-off-by Ilya Kuzmich <[email protected]>

This doesn't look bad, but what is the motivation behind the change? Is the current check not working for you?

Thanks!

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
#3 lore raw

PATCH 1/1 toolchain-external: improve musl external check

Hello,

Quoted 2 lines · Ilya Kuzmich

Current check fails on crosstool-ng musl toolchain, ctng puts libc.so at sysroot/usr/lib/, not sysroot/lib

OK, thanks, makes sense. I'll update the commit log with this explanation when applying.

Best regards,

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
Applied
#4 lore raw

PATCH 1/1 toolchain-external: improve musl external check

In reply to Ilya Kuzmich

Hello,

Quoted 8 lines · Ilya Kuzmich

Test whether musl used or not: compile minimal C program and check if interpreter contains /lib/ld-musl.

Signed-off-by Ilya Kuzmich <[email protected]>
---
 toolchain/helpers.mk                                   | 13 +++++++++----
 toolchain/toolchain-external/pkg-toolchain-external.mk |  4 +++-
 2 files changed, 12 insertions(+), 5 deletions(-)

Applied to master, thanks. However, I had to make a preliminary fix because TOOLCHAIN_EXTERNAL_READELF had a wrong value when Buildroot external toolchains were used.

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
author
#5 lore raw

PATCH 1/1 toolchain-external: improve musl external check

Turns out this is not an end to the story.

TOOLCHAIN_EXTERNAL_MUSL_LD_LINK @ pkg-toolchain-external.mk assumes that there is a /lib/libc.so. This is not a case for ct-ng musl toolchain. Ct-ng does this: sysroot/lib/ld-musl-armhf.so.1 -> ../usr/lib/libc.so

How do i fix this?
I've poked around pkg-toolchain-external.mk, but to no avail.

Quoted 21 lines · Thomas Petazzoni

Hello,

Quoted 8 lines · Ilya Kuzmich

Test whether musl used or not: compile minimal C program and check if interpreter contains /lib/ld-musl.

Signed-off-by Ilya Kuzmich <[email protected]>
---
 toolchain/helpers.mk                                   | 13 +++++++++----
 toolchain/toolchain-external/pkg-toolchain-external.mk |  4 +++-
 2 files changed, 12 insertions(+), 5 deletions(-)

Applied to master, thanks. However, I had to make a preliminary fix because TOOLCHAIN_EXTERNAL_READELF had a wrong value when Buildroot external toolchains were used.

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com