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Re: [PATCH roland/arm-preconfigure] Clean up ARM preconfigure.
On Fri, 8 Mar 2013, Roland McGrath wrote:
> > It's to avoid undefined references to unwinding functions at
> > configure-test time that would cause problems for -nostdlib link tests, so
> > it's set in the preconfigure script and then removed again in
> > sysdeps/unix/sysv/linux/arm/configure.in; it's not relevant to the build
> > itself.
>
> Please add some comments to both files explaining the situation.
I have applied this patch to add such comments.
diff --git a/ports/ChangeLog.arm b/ports/ChangeLog.arm
index 9db0b1b..8536181 100644
--- a/ports/ChangeLog.arm
+++ b/ports/ChangeLog.arm
@@ -1,3 +1,12 @@
+2013-03-11 Joseph Myers <joseph@codesourcery.com>
+
+ * sysdeps/arm/preconfigure.in: Add comment about
+ -fno-unwind-tables addition to CFLAGS.
+ * sysdeps/arm/preconfigure: Regenerated.
+ * sysdeps/unix/sysv/linux/arm/configure.in: Add comment about
+ -fno-unwind-tables removal from CFLAGS.
+ * sysdeps/unix/sysv/linux/arm/configure: Regenerated.
+
2013-03-11 Roland McGrath <roland@hack.frob.com>
* sysdeps/arm/bits/setjmp.h: Test [!__ASSEMBLER__] rather than [!_ASM].
diff --git a/ports/sysdeps/arm/preconfigure b/ports/sysdeps/arm/preconfigure
index 0042aaf..7ba1749 100644
--- a/ports/sysdeps/arm/preconfigure
+++ b/ports/sysdeps/arm/preconfigure
@@ -5,6 +5,11 @@ case "$machine" in
arm*)
case $config_os in
linux-gnueabi*)
+ # If the compiler enables unwind tables by default, this causes
+ # problems with undefined symbols in -nostdlib link tests. To
+ # avoid this, add -fno-unwind-tables here and remove it in
+ # sysdeps/unix/sysv/linux/arm/configure.in after those tests have
+ # been run.
if "${CFLAGS+set}" != "set" ; then
CFLAGS="-g -O2"
fi
diff --git a/ports/sysdeps/arm/preconfigure.in b/ports/sysdeps/arm/preconfigure.in
index f3272f1..99f2128 100644
--- a/ports/sysdeps/arm/preconfigure.in
+++ b/ports/sysdeps/arm/preconfigure.in
@@ -5,6 +5,11 @@ case "$machine" in
arm*)
case $config_os in
linux-gnueabi*)
+ # If the compiler enables unwind tables by default, this causes
+ # problems with undefined symbols in -nostdlib link tests. To
+ # avoid this, add -fno-unwind-tables here and remove it in
+ # sysdeps/unix/sysv/linux/arm/configure.in after those tests have
+ # been run.
if [ "${CFLAGS+set}" != "set" ]; then
CFLAGS="-g -O2"
fi
diff --git a/ports/sysdeps/unix/sysv/linux/arm/configure b/ports/sysdeps/unix/sysv/linux/arm/configure
index cb94cc5..f66b158 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/configure
+++ b/ports/sysdeps/unix/sysv/linux/arm/configure
@@ -2,4 +2,5 @@
# Local configure fragment for sysdeps/unix/sysv/linux/arm.
libc_cv_gcc_unwind_find_fde=no
+# Remove -fno-unwind-tables that was added in sysdeps/arm/preconfigure.in.
CFLAGS=${CFLAGS% -fno-unwind-tables}
diff --git a/ports/sysdeps/unix/sysv/linux/arm/configure.in b/ports/sysdeps/unix/sysv/linux/arm/configure.in
index 3e67dee..8fffe94 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/configure.in
+++ b/ports/sysdeps/unix/sysv/linux/arm/configure.in
@@ -2,4 +2,5 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/unix/sysv/linux/arm.
libc_cv_gcc_unwind_find_fde=no
+# Remove -fno-unwind-tables that was added in sysdeps/arm/preconfigure.in.
CFLAGS=${CFLAGS% -fno-unwind-tables}
--
Joseph S. Myers
joseph@codesourcery.com