[Buildroot] [PATCH 3/3] Adding support for uclibcpp library
Cjw X
cjwfirmware at vxmdesign.com
Thu Sep 17 07:07:46 UTC 2015
Hi Thomas, all,
(Sorry for the second email Thomas, didn't send the list)
You have some very valid concerns. For extremely small footprint
devices that want to use C++ I think this package will be useful, but
for now I'm not even using C++ in my embedded projects, so it is not
critical.
I don't think it is being maintained and it has some other issues, so,
I am going to leave this patch out for now.
Thanks!
-Chris
On Sun, Sep 13, 2015 at 6:00 PM, Thomas Petazzoni
<thomas.petazzoni at free-electrons.com> wrote:
> Chris,
>
> The commit title should probably be:
>
> toolchain: add support for the uclibcpp library
>
> On Sun, 13 Sep 2015 03:02:48 -0400, Chris Wardman wrote:
>> uclibcpp is built as an alternative to the standard libstdc++ library
>
> The question is how does it replace the libstdc++ provided by gcc? Does
> it simply overwrite it? So you're building C++ support in gcc normally
> and then overwrite the libstdc++ from gcc with uclibcpp ?
>
> Also, how compatible is it with the C++ standard? I.e will people be
> able to build arbitrary C++ libraries/applications with this smaller
> C++ library, or is it limited to a certain subset of the C++ standard?
>
>> diff --git a/package/uclibcpp/0.2.4/uclibcpp-0001-minor-fixes.patch b/package/uclibcpp/0.2.4/uclibcpp-0001-minor-fixes.patch
>> new file mode 100644
>> index 0000000..851b87e
>> --- /dev/null
>> +++ b/package/uclibcpp/0.2.4/uclibcpp-0001-minor-fixes.patch
>
> The patches shouldn't start with the package name, so a proper name is:
>
> 0001-minor-fixes.patch
>
> However, I believe this patch is really mixing too many things. Can you
> split this uclibcpp patch into smaller piece, each fixing one
> particular problem?
>
> Also, since we're supporting only one version of uclibcpp at a time,
> there is no need to put the patch in a 0.2.4/ subdirectory of
> package/uclibcpp/. Just put them directly in package/uclibcpp.
>
>> +I have no clude why they wrote the Unwind_Exception_Class variable that way, but that doesn't compile
>
> Please wrap the patch description to 80 columns, and don't use first
> person wording.
>
>> +diff -uNr uClibc++-0.2.4/src/_ct_chr.cpp uc_new/src/_ct_chr.cpp
>> +--- uClibc++-0.2.4/src/_ct_chr.cpp 1969-12-31 19:00:00.000000000 -0500
>> ++++ uc_new/src/_ct_chr.cpp 2015-01-15 16:29:21.478634145 -0500
>> +@@ -0,0 +1,18 @@
>> ++#include <_ansi.h>
>> ++#include <ctype.h>
>> ++
>> ++int _DEFUN(isspace, (c),int c){
>> ++ switch(c){
>> ++ case ' ':
>> ++ case '\r':
>> ++ case '\n':
>> ++ case '\b':
>> ++ case '\t':
>> ++ return true;
>> ++ }
>> ++ return false;
>> ++}
>> ++
>> ++int _DEFUN(isdigit, (c), int c){
>> ++ return ('0' <= c && c <= '9');
>> ++}
>
> newlib is not providing isspace() and isdigit() ?
>
>> diff --git a/package/uclibcpp/Config.in b/package/uclibcpp/Config.in
>> new file mode 100644
>> index 0000000..d0a962a
>> --- /dev/null
>> +++ b/package/uclibcpp/Config.in
>> @@ -0,0 +1,9 @@
>> +config BR2_PACKAGE_UCLIBCPP
>> + bool "uClibc++ C++ library"
>> + depends on BR2_TOOLCHAIN_BUILDROOT_NEWLIB
>> + depends on BR2_TOOLCHAIN_BUILDROOT_CXX
>> + help
>
> Please use tab for indentation.
>
>> + Uclibc++ library support. Smaller than libvstdc++
>
> And one tab + two spaces for the help text. Also, fix the typo in the
> description (libvstdc++ -> libstdc++) and maybe extend the description
> with more details (difference between the original libstdc++ and
> uclibcpp one).
>
>> +
>> +
>> +
>
> Unneeded empty lines.
>
>> diff --git a/package/uclibcpp/uclibcpp.config b/package/uclibcpp/uclibcpp.config
>> new file mode 100644
>> index 0000000..4e2d0ec
>> --- /dev/null
>> +++ b/package/uclibcpp/uclibcpp.config
>> @@ -0,0 +1,54 @@
>> +#
>> +# Automatically generated make config: don't edit
>> +#
>> +
>> +#
>> +# Target Features and Options
>> +#
>> +UCLIBCXX_HAS_FLOATS=y
>> +UCLIBCXX_HAS_LONG_DOUBLE=y
>> +UCLIBCXX_HAS_TLS=y
>> +WARNINGS="-Wall"
>> +BUILD_EXTRA_LIBRARIES=""
>> +HAVE_DOT_CONFIG=y
>> +
>> +#
>> +# String and I/O Stream Support
>> +#
>> +# UCLIBCXX_HAS_WCHAR is not set
>> +UCLIBCXX_IOSTREAM_BUFSIZE=32
>> +UCLIBCXX_HAS_LFS=y
>> +UCLIBCXX_SUPPORT_CDIR=y
>> +UCLIBCXX_SUPPORT_CIN=y
>> +UCLIBCXX_SUPPORT_COUT=y
>> +UCLIBCXX_SUPPORT_CERR=y
>> +# UCLIBCXX_SUPPORT_CLOG is not set
>> +
>> +#
>> +# STL and Code Expansion
>> +#
>> +UCLIBCXX_STL_BUFFER_SIZE=32
>> +UCLIBCXX_CODE_EXPANSION=y
>> +UCLIBCXX_EXPAND_CONSTRUCTORS_DESTRUCTORS=y
>> +UCLIBCXX_EXPAND_STRING_CHAR=y
>> +UCLIBCXX_EXPAND_VECTOR_BASIC=y
>> +UCLIBCXX_EXPAND_IOS_CHAR=y
>> +UCLIBCXX_EXPAND_STREAMBUF_CHAR=y
>> +UCLIBCXX_EXPAND_ISTREAM_CHAR=y
>> +UCLIBCXX_EXPAND_OSTREAM_CHAR=y
>> +UCLIBCXX_EXPAND_FSTREAM_CHAR=y
>> +UCLIBCXX_EXPAND_SSTREAM_CHAR=y
>> +
>> +#
>> +# Library Installation Options
>> +#
>> +UCLIBCXX_RUNTIME_PREFIX="/usr"
>> +UCLIBCXX_RUNTIME_INCLUDE_SUBDIR="/include"
>> +UCLIBCXX_RUNTIME_LIB_SUBDIR="/lib"
>> +UCLIBCXX_RUNTIME_BIN_SUBDIR="/bin"
>> +UCLIBCXX_EXCEPTION_SUPPORT=y
>> +IMPORT_LIBSUP=y
>> +# IMPORT_LIBGCC_EH is not set
>> +BUILD_STATIC_LIB=y
>> +BUILD_ONLY_STATIC_LIB=y
>> +# DODEBUG is not set
>> diff --git a/package/uclibcpp/uclibcpp.mk b/package/uclibcpp/uclibcpp.mk
>> new file mode 100644
>> index 0000000..dfe8ede
>> --- /dev/null
>> +++ b/package/uclibcpp/uclibcpp.mk
>> @@ -0,0 +1,28 @@
>
> Missing comment header. Also please add a hash file (see
> http://buildroot.uclibc.org/downloads/manual/manual.html#adding-packages-hash).
> Maybe I forgot to say that in my review of your newlib package, but
> please do it there as well.
>
>> +UCLIBCPP_VERSION = 0.2.4
>> +UCLIBCPP_SOURCE = uClibc++-$(UCLIBCPP_VERSION).tar.bz2
>
> The last version is from May 2012, like uClibc itself. Is it a dead
> project like uClibc ? If so, then I'm a bit worried in packaging
> something so fundamental as the standard C++ library if it isn't
> maintained.
>
> There has been a few commits since the last release, see
> http://git.uclibc.org/uClibc++/log/. But it still doesn't seem to be
> very active. According to the website, there is not even a mailing list
> for it.
>
> You could use the .tar.xz tarball instead of .tar.bz2.
>
>> +UCLIBCPP_LICENSE = LGPLv3
>
> Some quick inspection indicates LGPLv2.1+
>
>> +UCLIBCPP_SITE = http://cxx.uclibc.org/src/
>> +
>> +UCLIBCPP_INSTALL_STAGING = YES
>> +
>> +UCLIBCPP_DEPENDENCIES = host-gcc-final
>
> All target packages depend on "toolchain", which has host-gcc-final as
> part of its dependencies. However maybe, what you need is to have this
> uclibcpp package built *before* any other target package that uses C++,
> no? If so, then toolchain/toolchain/toolchain.mk needs to be modified
> to add uclibcpp as a dependency when it is enabled. And of course,
> uclibcpp.mk should specify UCLIBCPP_ADD_TOOLCHAIN_DEPENDENCY = NO.
>
>> +
>> +UCLIBCPP_KCONFIG_FILE = $(TOPDIR)/package/uclibcpp/uclibcpp.config
>
> $(TOPDIR)/ not needed.
>
>> +
>> +UCLIBCPP_MAKE_FLAGS = CROSS=$(TARGET_CROSS)
>> +
>> +define UCLIBCPP_BUILD_CMDS
>> + $(MAKE) -C $(@D) $(UCLIBCPP_MAKE_FLAGS)
>> +endef
>> +
>> +define UCLIBCPP_INSTALL_STAGING_CMDS
>> + $(MAKE) -C $(@D) PREFIX=$(STAGING_DIR) install
>> +endef
>> +
>> +define UCLIBCPP_INSTALL_TARGET_CMDS
>> + $(MAKE) -C $(@D) PREFIX=$(TARGET_DIR) install
>> +endef
>> +
>> +$(eval $(kconfig-package))
>> +
>> +
>
> Unneeded empty lines at the end of the file.
>
>> diff --git a/toolchain/Config.in b/toolchain/Config.in
>> index 88ebe8c..3904f44 100644
>> --- a/toolchain/Config.in
>> +++ b/toolchain/Config.in
>> @@ -60,5 +60,6 @@ endchoice
>> source "toolchain/toolchain-buildroot/Config.in"
>> source "toolchain/toolchain-external/Config.in"
>> source "toolchain/toolchain-common.in"
>> +source "package/uclibcpp/Config.in"
>
> This should go in toolchain/toolchain-buildroot/Config.in.
>
> Best regards,
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
More information about the buildroot
mailing list