[Buildroot] [PATCH v3 1/2] toolchain-external: add a check for unsupported toolchains

[Buildroot] [PATCH v3 1/2] toolchain-external: add a check for unsupported toolchains

[Romain Naour]

Some toolchain can't be used by Buildroot due to sysroot location
issue, so the $(ARCH)-linux-gnu-gcc -print-file-name=libc.a command
return only "libc.a"

This lead to an error during the header check version helper,
so these toolchains can't be imported into Buildroot.

cc1: fatal error: $PWD/libc.a/usr/include/linux/version.h: No such file or directory
compilation terminated.
support/scripts/check-kernel-headers.sh: line 38: /tmp/check-headers.4V5PPF: Permission denied

This issue happen with the first linaro 2015.11 [1] release and
CodeSourcery standard edition [2].

Here is the sysroot directory tree for linaro 2015.11:
$ ls libc/arm-linux-gnueabihf
etc  lib  sbin  usr  var

Here is the sysroot directory tree for CodeSourcery standard:
$ ls libc/sgxx-glibc
etc  lib  lib64  sbin  usr  var

Add a check to error out with an explicit error message

The check don't use toolchain_find_libc_a function directly since
"realpath -f" is used internally and return an absolute path.

[1] https://bugs.linaro.org/show_bug.cgi?id=1995#c7
[2] http://lists.busybox.net/pipermail/buildroot/2014-October/110696.html

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
v3: rename non_existent_sysroot to libc_a_path (ThomasP)
v2: move the check to check_unusable_toolchain helper
    use unsupported toolchain instead of broken toolchains (ThomasP)
---
 toolchain/helpers.mk | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
index 02cc0bb..6102371 100644
--- a/toolchain/helpers.mk
+++ b/toolchain/helpers.mk
@@ -418,6 +418,11 @@ check_unusable_toolchain = \
 		echo "and contain a lot of pre-built libraries that would conflict with"; \
 		echo "the ones Buildroot wants to build."; \
 		exit 1; \
+	fi; \
+	libc_a_path=`$${__CROSS_CC} -print-file-name=libc.a` ; \
+	if test "$${libc_a_path}" = "libc.a" ; then \
+		echo "Unable to detect the toolchain sysroot, Buildroot cannot handle this toolchain." ; \
+		exit 1 ; \
 	fi
 
 #
-- 
2.4.3

[Buildroot] [PATCH v3 2/2] toolchain-external: move the sysroot toolchain support check to helper function

[Romain Naour]

The sysroot toolchain support check is duplicated at three locations in the
external toolchain infra. So move it inside the check_unusable_toolchain helper
that is called when the toolchain package is configured
(TOOLCHAIN_EXTERNAL_CONFIGURE_CMDS).

All checks in TOOLCHAIN_EXTERNAL_INSTALL_SYSROOT_LIBS and
TOOLCHAIN_EXTERNAL_INSTALL_TARGET_LIBS can be safely removed since it's already
done in TOOLCHAIN_EXTERNAL_CONFIGURE_CMDS.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
v3: add missing exit 1
    s/$(__CROSS_CC)/$${__CROSS_CC}/
    Improve commit log (ThomasP)
v2: new patch
---
 toolchain/helpers.mk                               |  5 +++++
 toolchain/toolchain-external/toolchain-external.mk | 14 +-------------
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
index 6102371..8a776f2 100644
--- a/toolchain/helpers.mk
+++ b/toolchain/helpers.mk
@@ -423,6 +423,11 @@ check_unusable_toolchain = \
 	if test "$${libc_a_path}" = "libc.a" ; then \
 		echo "Unable to detect the toolchain sysroot, Buildroot cannot handle this toolchain." ; \
 		exit 1 ; \
+	fi ; \
+	sysroot_dir="$(call toolchain_find_sysroot,$${__CROSS_CC})" ; \
+	if test -z "$${sysroot_dir}" ; then \
+		echo "External toolchain doesn't support --sysroot. Cannot use." ; \
+		exit 1 ; \
 	fi
 
 #
diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
index 518afd6..5ad6309 100644
--- a/toolchain/toolchain-external/toolchain-external.mk
+++ b/toolchain/toolchain-external/toolchain-external.mk
@@ -467,17 +467,13 @@ $$(printf $(call toolchain_find_libc_a,$(1)) | sed -r -e 's:.*/(usr/)?(lib(32|64
 endef
 
 # Checks for an already installed toolchain: check the toolchain
-# location, check that it supports sysroot, and then verify that it
+# location, check that it is usable, and then verify that it
 # matches the configuration provided in Buildroot: ABI, C++ support,
 # kernel headers version, type of C library and all C library features.
 define TOOLCHAIN_EXTERNAL_CONFIGURE_CMDS
 	$(Q)$(call check_cross_compiler_exists,$(TOOLCHAIN_EXTERNAL_CC))
 	$(Q)$(call check_unusable_toolchain,$(TOOLCHAIN_EXTERNAL_CC))
 	$(Q)SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC))" ; \
-	if test -z "$${SYSROOT_DIR}" ; then \
-		@echo "External toolchain doesn't support --sysroot. Cannot use." ; \
-		exit 1 ; \
-	fi ; \
 	$(call check_kernel_headers_version,\
 		$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC)),\
 		$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST))); \
@@ -588,10 +584,6 @@ endef
 
 define TOOLCHAIN_EXTERNAL_INSTALL_TARGET_LIBS
 	$(Q)SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC))" ; \
-	if test -z "$${SYSROOT_DIR}" ; then \
-		@echo "External toolchain doesn't support --sysroot. Cannot use." ; \
-		exit 1 ; \
-	fi ; \
 	ARCH_SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
 	ARCH_LIB_DIR="$(call toolchain_find_libdir,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
 	SUPPORT_LIB_DIR="" ; \
@@ -633,10 +625,6 @@ endef
 
 define TOOLCHAIN_EXTERNAL_INSTALL_SYSROOT_LIBS
 	$(Q)SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC))" ; \
-	if test -z "$${SYSROOT_DIR}" ; then \
-		@echo "External toolchain doesn't support --sysroot. Cannot use." ; \
-		exit 1 ; \
-	fi ; \
 	ARCH_SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
 	ARCH_LIB_DIR="$(call toolchain_find_libdir,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
 	SUPPORT_LIB_DIR="" ; \
-- 
2.4.3