diff mbox

UCLIBC_EXTRA_CFLAGS in uClibc overridden while using buildroot

Message ID 43F7AEDD312F9E499A1A4E3608E505ED2ABF14F2@SJEXCHMB09.corp.ad.broadcom.com
State Rejected
Delegated to: Thomas De Schampheleire
Headers show

Commit Message

Rajendra Dendukuri June 7, 2013, 9:08 p.m. UTC 
Thanks for the inputs. The said patch works. Can we get this into release buildroot source tree.

/rajen
-----Original Message-----
From: Thomas Petazzoni [mailto:thomas.petazzoni@free-electrons.com] 
Sent: Friday, June 07, 2013 5:55 AM
To: Rajendra Dendukuri
Cc: buildroot@busybox.net
Subject: Re: [Buildroot] UCLIBC_EXTRA_CFLAGS in uClibc overridden while using buildroot

Dear Rajendra Dendukuri,

On Thu, 6 Jun 2013 19:33:30 +0000, Rajendra Dendukuri wrote:
> I am using buildroot-2012.11 version to build a uClibc toolchain for ARMv7a. I find that uClibc/Rules.mak file defaults to -Os. However I wish to include "-fno-omit-frame-pointer" even when -Os optimization is used. I cannot find a hook in buildroot or uClibc where this can be done. I tried setting the value of UCLIBC_EXTRA_CFGLAGS in the uClibc config file. However that is not being considered. Instead the values passed by buildroot in  "toolchain/uClibc/uclibc.mk" are being used.
> 
> This seems to be a very stiff limitation while using uClibc with buildroot. Any suggestions on how we can overcome this.

Can you try the following patch, and add -fno-omit-frame-pointer to
BR2_TARGET_OPTIMIZATION ?

Comments

Gustavo Zacarias March 3, 2014, 10:37 p.m. UTC | #1 
On 06/07/2013 06:08 PM, Rajendra Dendukuri wrote:

> Thanks for the inputs. The said patch works. Can we get this into release buildroot source tree.

Hi.
Revived old thread!
It may work for your particular case, but generally, it's a bad idea to
allow tweaking libc build CFLAGS, specially when they're merged with
package CFLAGS.
What's the intention of this, fixing some problem or just plain
optimization?
The patch as it is right now would break PowerPC SPE ABI toolchains and
probably Xtensa to a certain degree too (see package/Makefile.in)
A config option with separate extra CFLAGS for uClibc could be
introduced, but really, if it's not fixing anything in particular, why?
If you're fixing some issue in a determined fixed scenario then it might
be good to make it automatic.
Regards.
Thomas Petazzoni June 1, 2014, 12:51 p.m. UTC | #2 
Hello,

On Mon, 03 Mar 2014 19:37:17 -0300, Gustavo Zacarias wrote:
> On 06/07/2013 06:08 PM, Rajendra Dendukuri wrote:
> 
> > Thanks for the inputs. The said patch works. Can we get this into release buildroot source tree.
> 
> Hi.
> Revived old thread!
> It may work for your particular case, but generally, it's a bad idea to
> allow tweaking libc build CFLAGS, specially when they're merged with
> package CFLAGS.
> What's the intention of this, fixing some problem or just plain
> optimization?
> The patch as it is right now would break PowerPC SPE ABI toolchains and
> probably Xtensa to a certain degree too (see package/Makefile.in)
> A config option with separate extra CFLAGS for uClibc could be
> introduced, but really, if it's not fixing anything in particular, why?
> If you're fixing some issue in a determined fixed scenario then it might
> be good to make it automatic.

Almost three months later after Gustavo's request for more details, the
original submitter hasn't provide these details. I'm therefore marking
the patch as Rejected in patchwork. Rajendra, if you think your patch
is still useful, please resend an updated version, with a more detailed
explanation of the cases where it is needed.

Thanks,

Thomas
diff mbox

Patch

diff --git a/toolchain/uClibc/uclibc.mk b/toolchain/uClibc/uclibc.mk
index d4f1d4c..8ecb712 100644
--- a/toolchain/uClibc/uclibc.mk
+++ b/toolchain/uClibc/uclibc.mk
@@ -392,7 +392,7 @@  $(UCLIBC_DIR)/.config: $(UCLIBC_DIR)/.oldconfig
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=$(TOOLCHAIN_DIR)/uClibc_dev/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		HOSTCC="$(HOSTCC)" \
 		oldconfig
 	touch $@
@@ -423,7 +423,7 @@  $(UCLIBC_DIR)/.configured: $(LINUX_HEADERS_DIR)/.configured $(UCLIBC_DIR)/.confi
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=$(TOOLCHAIN_DIR)/uClibc_dev/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		HOSTCC="$(HOSTCC)" headers \
 		lib/crt1.o lib/crti.o lib/crtn.o \
 		install_headers
@@ -446,7 +446,7 @@  $(UCLIBC_DIR)/lib/libc.a: $(UCLIBC_DIR)/.configured $(gcc_intermediate) $(LIBFLO
 		DEVEL_PREFIX=/ \
 		RUNTIME_PREFIX=/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		HOSTCC="$(HOSTCC)" \
 		all
 	touch -c $@
@@ -458,7 +458,7 @@  uclibc-menuconfig: dirs $(UCLIBC_DIR)/.config
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=$(TOOLCHAIN_DIR)/uClibc_dev/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		HOSTCC="$(HOSTCC)" \
 		menuconfig && \
 	touch -c $(UCLIBC_DIR)/.config
@@ -472,7 +472,7 @@  $(STAGING_DIR)/usr/lib/libc.a: $(UCLIBC_DIR)/lib/libc.a
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		install_runtime install_dev
 	# Install the kernel headers to the staging dir if necessary
 	if [ ! -f $(STAGING_DIR)/usr/include/linux/version.h ]; then \
@@ -503,7 +503,7 @@  $(TARGET_DIR)/lib/libc.so.0: $(STAGING_DIR)/usr/lib/libc.a
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=/ \
 		CROSS_COMPILE="$(TARGET_CROSS)" \
-		UCLIBC_EXTRA_CFLAGS="$(TARGET_ABI)" \
+		UCLIBC_EXTRA_CFLAGS="$(TARGET_CFLAGS)" \
 		install_runtime
 	touch -c $@