[Buildroot] [PATCH] Improved uClibc support with crosstool-ng generated toolchain

Yann E. MORIN yann.morin.1998 at anciens.enib.fr
Fri Dec 2 21:54:51 UTC 2011 

Will, All,

Please CC: me next time! ;-)

On Friday 02 December 2011 16:53:26 Will Wagner wrote:
> Currently there is a hard coded uClibc config file when building
> with crosstools-ng. This patch:
> - Allows user to pick uClibc version when using ct-ng
> - Allows user to select nptl when using 0.9.32
> - Supplys better default uClibc config files (Using same config files as for internal buildroot config)
> - Allows user to specify a custom uClibc config file

Globally, nothing really wrong IMHO.

The only comment is: make separate patches for each changes. I would suggest
this ordering:
 1/4 Allows user to pick uClibc version when using ct-ng
 2/4 Supplys better default uClibc config files
 3/4 Allows user to specify a custom uClibc config file
 4/4 Allows user to select nptl when using 0.9.32

See some other comments below...

> Signed-off-by: Will Wagner <will_wagner at carallon.com>
> ---
>  toolchain/toolchain-crosstool-ng/Config.in       |   28 +++-
>  toolchain/toolchain-crosstool-ng/crosstool-ng.mk |   14 ++-
>  toolchain/toolchain-crosstool-ng/uClibc.config   |  246 ----------------------
>  3 files changed, 40 insertions(+), 248 deletions(-)
>  delete mode 100644 toolchain/toolchain-crosstool-ng/uClibc.config
> 
> diff --git a/toolchain/toolchain-crosstool-ng/Config.in b/toolchain/toolchain-crosstool-ng/Config.in
> index 2d1e801..7e21ce9 100644
> --- a/toolchain/toolchain-crosstool-ng/Config.in
> +++ b/toolchain/toolchain-crosstool-ng/Config.in
> @@ -50,6 +50,30 @@ if BR2_TOOLCHAIN_CTNG_uClibc
>  
>  comment "Toolchain Options"
>  
> +choice
> +	prompt "uClibc C library Version"
> +	default BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_30
> +	help
> +	  Select the version of uClibc you wish to use.
> +
> +	config BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_30
> +		bool "uClibc 0.9.30.x"
> +
> +	config BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32
> +		bool "uClibc 0.9.32.x"
> +
> +endchoice
> +
> +config BR2_TOOLCHAIN_CTNG_uClibc_CONFIG
> +	string "uClibc configuration file to use?"
> +	default "toolchain/uClibc/uClibc-0.9.30.config" if BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_30
> +	default "toolchain/uClibc/uClibc-0.9.32.config" if BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32
> +	help
> +	  Some people may wish to use their own modified uClibc configuration
> +	  file and will specify their config file location with this option.
> +	  See also docs/README in this package.
> +	  If unsure, use the default.
> +
>  config BR2_TOOLCHAIN_CTNG_uClibc_LARGEFILE
>  	bool "Enable large file (files > 2 GB) support"
>  	select BR2_LARGEFILE
> @@ -130,7 +154,9 @@ choice
>  		bool "Native POSIX Threading (NPTL)"
>  		select BR2_TOOLCHAIN_HAS_THREADS
>  		depends on BR2_TOOLCHAIN_CTNG_eglibc || \
> -			   BR2_TOOLCHAIN_CTNG_glibc
> +		           BR2_TOOLCHAIN_CTNG_glibc || \
> +		           BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32
> +

This means that, when newer uClibc version come out, we'll have to maintain
this 'depends on'. I'd suggest:

config BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32
    bool "0.9.32"
    select BR2_TOOLCHAIN_CTNG_uClibc_NPTL_OK

config BR2_TOOLCHAIN_CTNG_uClibc_NPTL_OK
    bool

config BR2_TOOLCHAIN_CTNG_THREADS_NPTL
    bool "NPTL"
    depends on glibc || eglibc || BR2_TOOLCHAIN_CTNG_uClibc_NPTL_OK

(Note: I used shortened names for readability only, this should not be
used as-is, of course!)

>  endchoice
>  
>  endif # BR2_TOOLCHAIN_CTNG
> diff --git a/toolchain/toolchain-crosstool-ng/crosstool-ng.mk b/toolchain/toolchain-crosstool-ng/crosstool-ng.mk
> index 3a205dd..4311097 100644
> --- a/toolchain/toolchain-crosstool-ng/crosstool-ng.mk
> +++ b/toolchain/toolchain-crosstool-ng/crosstool-ng.mk
> @@ -10,7 +10,7 @@
>  
>  CTNG_DIR := $(BUILD_DIR)/build-toolchain
>  
> -CTNG_UCLIBC_CONFIG_FILE := $(TOPDIR)/toolchain/toolchain-crosstool-ng/uClibc.config
> +CTNG_UCLIBC_CONFIG_FILE := $(call qstrip,$(BR2_TOOLCHAIN_CTNG_uClibc_CONFIG))
>  CTNG_CONFIG_FILE:=$(call qstrip,$(BR2_TOOLCHAIN_CTNG_CONFIG))
>  
>  # Hack! ct-ng is in fact a Makefile script. As such, it accepts all
> @@ -267,6 +267,18 @@ CTNG_FIX_DOT_CONFIG_PATHS_SED += s:^(CT_SYSROOT_DIR_PREFIX)=.*:\1="":;
>  # uClibc specific options
>  ifeq ($(BR2_TOOLCHAIN_CTNG_uClibc),y)
>  
> +# Set version
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_32).*:\# \2 is not set:;
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_30_3).*:\# \2 is not set:;
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_30_2).*:\# \2 is not set:;
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_30_1).*:\# \2 is not set:;
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_30).*:\# \2 is not set:;
> +ifneq ($(call qstrip,$(BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32)),)
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_32).*:\2=y:;
> +else ifneq ($(call qstrip,$(BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_30)),)
> +CTNG_FIX_DOT_CONFIG_SED += s:^(|\# )(CT_LIBC_UCLIBC_V_0_9_30_3).*:\2=y:;
> +endif

You'll get the same issue as the LT_NEW vs. LT_OLD you mentioned earlier.
Also, I do not like negative tests:
  ifneq ($(blabla),)
  do blabla stuff
would be better written thus:
  ifeq ($(blabla),y)
  do blabla stuff

The following should be OK (untested, may need some tweaking)

# Set version
ifeq ($(call qstrip,$(BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_32)),y)
CTNG_FIX_DOT_CONFIG_SED += s:^(CT_LIBC_UCLIBC_V)(.+)=y$$:# \1\2 is not set\n\1_0_9_32=y:;
else ifeq ($(call qstrip,$(BR2_TOOLCHAIN_CTNG_uClibc_VERSION_0_9_30)),y)
CTNG_FIX_DOT_CONFIG_SED += s:^(CT_LIBC_UCLIBC_V)(.+)=y$$:# \1\2 is not set\n\1_0_9_30=y:;
endif

Otherwise, pretty OK for me. Care to address the above, so I can test
and apply my tag-lines?

Regards,
Yann E. MORIN.

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