Re: [PATCH v2] C++ : Add the -stdlib= option.
Hi Iain, could you add a note about this change to the
gcc-11/changes.html page? There are probably some people who would be
interested in this who could use a note about it. Thanks
On Tue, Dec 22, 2020 at 3:53 PM Jason Merrill via Gcc-patches
wrote:
>
> On 12/22/20 3:39 PM, Iain Sandoe wrote:
> > Hi Jason,
> >
> > Jason Merrill wrote:
> >
> >> On 11/11/20 3:58 PM, Iain Sandoe wrote:
> >
> >>> This option allows the user to specify alternate C++ runtime libraries,
> >>> for example when a platform uses libc++ as the installed C++ runtime.
> >>> It is the same spelling as a clang option that allows that to use
> >>> libstdc++.
> >>> I have had this patch for some time now (more than a year) on Darwin
> >>> branches.
> >>>
> >
> >>> + /* Which standard library to link.
> >>> + 1 = libstdc++
> >>> + 2 = libc++. */
> >>> + int which_library = 1;
> >>
> >> Even if this variable is an int, let's introduce an enum for comparing it
> >> to specific values.
> >
> > done - it is also noted that it must track the enum in the opt file.
> >
> >>> @@ -264,6 +293,8 @@ lang_specific_driver (struct cl_decoded_option
> >>> **in_decoded_options,
> >>> /* Add one for shared_libgcc or extra static library. */
> >>> num_args = argc + added + need_math + (library > 0) * 4 + 1;
> >>> + if (which_library > 1 && LIBCXXABI != NULL)
> >>> +num_args += 4;
> >>
> >> Why does libc++ need more args than libstdc++? Please add a comment.
> >
> > done (JFTR, it’s because libc++ doesn’t include the abi library for most
> > platforms, so that also has to be
> > appended to the link line).
> >
> >>> +#ifdef GPLUSPLUS_LIBCXX_INCLUDE_DIR
> >>> +/* Pick up libc++ include files, if we have -stdlib=libc++. */
> >>> +{ GPLUSPLUS_LIBCXX_INCLUDE_DIR, "G++", 2, 1,
> >>
> >> If you're going to give cplusplus a non-boolean value, the comment in
> >> cppdefault.h needs to reflect that.
> >
> > done.
> >
> > (re-)tested on x86_64-darwin{11,16,17,19, 20} with the installed libc++ and
> > x86_64-linux-gnu with an
> > LLVM-9 build. Bootstrapped and smoke-tested for libc++ (regular testing
> > for libstdc++).
> >
> > OK for master now?
>
> OK.
>
> > thanks
> > Iain
> >
> > revised patch
> >
> >
> > This option allows the user to specifiy alternate C++ runtime libraries,
> > for example when a platform uses libc++ as the installed C++ runtime.
> >
> > We introduce the command line option: -stdlib= which is the user-facing
> > mechanism to select the C++ runtime to be used when compiling and linking
> > code. This is the same option spelling as that used by clang to allow the
> > use of libstdc++.
> >
> > The availability (and thus function) of the option are a configure-time
> > choice using the configuration control:
> > --with-gxx-libcxx-include-dir=
> >
> > Specification of the path for the libc++ headers, enables the -stdlib=
> > option (using the path as given), default values are set when the path
> > is unconfigured.
> >
> > If --with-gxx-libcxx-include-dir is given together with --with-sysroot=,
> > then we test to see if the include path starts with the sysroot and, if so,
> > record the sysroot-relative component as the local path. At runtime, we
> > prepend the sysroot that is actually active.
> >
> > At link time, we use the C++ runtime in force and (if that is libc++) also
> > append the libc++abi ABI library. As for other cases, if a target sets the
> > name pointer for the ABI library to NULL the G++ driver will omit it from
> > the link line.
> >
> > gcc/ChangeLog:
> >
> > * configure.ac: Add gxx-libcxx-include-dir handled
> > in the same way as the regular cxx header directory.
> > * Makefile.in: Regenerated.
> > * config.in: Likewise.
> > * configure: Likewise.
> > * cppdefault.c: Pick up libc++ headers if the option
> > is enabled.
> > * cppdefault.h (struct default_include): Amend comments
> > to reflect the extended use of the cplusplus field.
> > * incpath.c (add_standard_paths): Allow for multiple
> > c++ header include path variants.
> > * doc/invoke.texi: Document the -stdlib= option.
> >
> > gcc/c-family/ChangeLog:
> >
> > * c.opt: Add -stdlib= option and enumerations for
> > libstdc++ and libc++.
> >
> > gcc/cp/ChangeLog:
> >
> > * g++spec.c (LIBCXX, LIBCXX_PROFILE, LIBCXX_STATIC): New.
> > (LIBCXXABI, LIBCXXABI_PROFILE, LIBCXXABI_STATIC): New.
> > (enum stdcxxlib_kind): New.
> > (lang_specific_driver): Allow selection amongst multiple
> > c++ runtime libraries.
> > ---
> > gcc/Makefile.in | 6
> > gcc/c-family/c.opt | 14 +
> > gcc/config.in | 6
> > gcc/configure | 57 --
> > gcc/configure.ac| 44 +++
> > gcc/cp/g++spec.c| 74 -
> > gcc/cppdefault.c| 5 +++
> > gcc/cppdefault.h| 7 -
> >
Re: [PATCH v2] C++ : Add the -stdlib= option.
On 12/22/20 3:39 PM, Iain Sandoe wrote:
Hi Jason,
Jason Merrill wrote:
On 11/11/20 3:58 PM, Iain Sandoe wrote:
This option allows the user to specify alternate C++ runtime libraries,
for example when a platform uses libc++ as the installed C++ runtime.
It is the same spelling as a clang option that allows that to use libstdc++.
I have had this patch for some time now (more than a year) on Darwin
branches.
+ /* Which standard library to link.
+ 1 = libstdc++
+ 2 = libc++. */
+ int which_library = 1;
Even if this variable is an int, let's introduce an enum for comparing it to
specific values.
done - it is also noted that it must track the enum in the opt file.
@@ -264,6 +293,8 @@ lang_specific_driver (struct cl_decoded_option
**in_decoded_options,
/* Add one for shared_libgcc or extra static library. */
num_args = argc + added + need_math + (library > 0) * 4 + 1;
+ if (which_library > 1 && LIBCXXABI != NULL)
+num_args += 4;
Why does libc++ need more args than libstdc++? Please add a comment.
done (JFTR, it’s because libc++ doesn’t include the abi library for most
platforms, so that also has to be
appended to the link line).
+#ifdef GPLUSPLUS_LIBCXX_INCLUDE_DIR
+/* Pick up libc++ include files, if we have -stdlib=libc++. */
+{ GPLUSPLUS_LIBCXX_INCLUDE_DIR, "G++", 2, 1,
If you're going to give cplusplus a non-boolean value, the comment in
cppdefault.h needs to reflect that.
done.
(re-)tested on x86_64-darwin{11,16,17,19, 20} with the installed libc++ and
x86_64-linux-gnu with an
LLVM-9 build. Bootstrapped and smoke-tested for libc++ (regular testing for
libstdc++).
OK for master now?
OK.
thanks
Iain
revised patch
This option allows the user to specifiy alternate C++ runtime libraries,
for example when a platform uses libc++ as the installed C++ runtime.
We introduce the command line option: -stdlib= which is the user-facing
mechanism to select the C++ runtime to be used when compiling and linking
code. This is the same option spelling as that used by clang to allow the
use of libstdc++.
The availability (and thus function) of the option are a configure-time
choice using the configuration control:
--with-gxx-libcxx-include-dir=
Specification of the path for the libc++ headers, enables the -stdlib=
option (using the path as given), default values are set when the path
is unconfigured.
If --with-gxx-libcxx-include-dir is given together with --with-sysroot=,
then we test to see if the include path starts with the sysroot and, if so,
record the sysroot-relative component as the local path. At runtime, we
prepend the sysroot that is actually active.
At link time, we use the C++ runtime in force and (if that is libc++) also
append the libc++abi ABI library. As for other cases, if a target sets the
name pointer for the ABI library to NULL the G++ driver will omit it from
the link line.
gcc/ChangeLog:
* configure.ac: Add gxx-libcxx-include-dir handled
in the same way as the regular cxx header directory.
* Makefile.in: Regenerated.
* config.in: Likewise.
* configure: Likewise.
* cppdefault.c: Pick up libc++ headers if the option
is enabled.
* cppdefault.h (struct default_include): Amend comments
to reflect the extended use of the cplusplus field.
* incpath.c (add_standard_paths): Allow for multiple
c++ header include path variants.
* doc/invoke.texi: Document the -stdlib= option.
gcc/c-family/ChangeLog:
* c.opt: Add -stdlib= option and enumerations for
libstdc++ and libc++.
gcc/cp/ChangeLog:
* g++spec.c (LIBCXX, LIBCXX_PROFILE, LIBCXX_STATIC): New.
(LIBCXXABI, LIBCXXABI_PROFILE, LIBCXXABI_STATIC): New.
(enum stdcxxlib_kind): New.
(lang_specific_driver): Allow selection amongst multiple
c++ runtime libraries.
---
gcc/Makefile.in | 6
gcc/c-family/c.opt | 14 +
gcc/config.in | 6
gcc/configure | 57 --
gcc/configure.ac| 44 +++
gcc/cp/g++spec.c| 74 -
gcc/cppdefault.c| 5 +++
gcc/cppdefault.h| 7 -
gcc/doc/invoke.texi | 10 ++
gcc/incpath.c | 6 ++--
10 files changed, 216 insertions(+), 13 deletions(-)
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 178e4eaa513..6847022f108 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -679,6 +679,9 @@ build_tooldir = $(exec_prefix)/$(target_noncanonical)
# Directory in which the compiler finds target-independent g++ includes.
gcc_gxx_include_dir = @gcc_gxx_include_dir@
gcc_gxx_include_dir_add_sysroot = @gcc_gxx_include_dir_add_sysroot@
+# Directory in which the compiler finds libc++ includes.
+gcc_gxx_libcxx_include_dir = @gcc_gxx_libcxx_include_dir@
+gcc_gxx_libcxx_include_dir_add_sysroot =
@gcc_gxx_libcxx_include_dir_add_sysroot@
# Directory
[PATCH v2] C++ : Add the -stdlib= option.
Hi Jason,
Jason Merrill wrote:
> On 11/11/20 3:58 PM, Iain Sandoe wrote:
>> This option allows the user to specify alternate C++ runtime libraries,
>> for example when a platform uses libc++ as the installed C++ runtime.
>> It is the same spelling as a clang option that allows that to use libstdc++.
>> I have had this patch for some time now (more than a year) on Darwin
>> branches.
>>
>> + /* Which standard library to link.
>> + 1 = libstdc++
>> + 2 = libc++. */
>> + int which_library = 1;
>
> Even if this variable is an int, let's introduce an enum for comparing it to
> specific values.
done - it is also noted that it must track the enum in the opt file.
>> @@ -264,6 +293,8 @@ lang_specific_driver (struct cl_decoded_option
>> **in_decoded_options,
>> /* Add one for shared_libgcc or extra static library. */
>> num_args = argc + added + need_math + (library > 0) * 4 + 1;
>> + if (which_library > 1 && LIBCXXABI != NULL)
>> +num_args += 4;
>
> Why does libc++ need more args than libstdc++? Please add a comment.
done (JFTR, it’s because libc++ doesn’t include the abi library for most
platforms, so that also has to be
appended to the link line).
>> +#ifdef GPLUSPLUS_LIBCXX_INCLUDE_DIR
>> +/* Pick up libc++ include files, if we have -stdlib=libc++. */
>> +{ GPLUSPLUS_LIBCXX_INCLUDE_DIR, "G++", 2, 1,
>
> If you're going to give cplusplus a non-boolean value, the comment in
> cppdefault.h needs to reflect that.
done.
(re-)tested on x86_64-darwin{11,16,17,19, 20} with the installed libc++ and
x86_64-linux-gnu with an
LLVM-9 build. Bootstrapped and smoke-tested for libc++ (regular testing for
libstdc++).
OK for master now?
thanks
Iain
revised patch
This option allows the user to specifiy alternate C++ runtime libraries,
for example when a platform uses libc++ as the installed C++ runtime.
We introduce the command line option: -stdlib= which is the user-facing
mechanism to select the C++ runtime to be used when compiling and linking
code. This is the same option spelling as that used by clang to allow the
use of libstdc++.
The availability (and thus function) of the option are a configure-time
choice using the configuration control:
--with-gxx-libcxx-include-dir=
Specification of the path for the libc++ headers, enables the -stdlib=
option (using the path as given), default values are set when the path
is unconfigured.
If --with-gxx-libcxx-include-dir is given together with --with-sysroot=,
then we test to see if the include path starts with the sysroot and, if so,
record the sysroot-relative component as the local path. At runtime, we
prepend the sysroot that is actually active.
At link time, we use the C++ runtime in force and (if that is libc++) also
append the libc++abi ABI library. As for other cases, if a target sets the
name pointer for the ABI library to NULL the G++ driver will omit it from
the link line.
gcc/ChangeLog:
* configure.ac: Add gxx-libcxx-include-dir handled
in the same way as the regular cxx header directory.
* Makefile.in: Regenerated.
* config.in: Likewise.
* configure: Likewise.
* cppdefault.c: Pick up libc++ headers if the option
is enabled.
* cppdefault.h (struct default_include): Amend comments
to reflect the extended use of the cplusplus field.
* incpath.c (add_standard_paths): Allow for multiple
c++ header include path variants.
* doc/invoke.texi: Document the -stdlib= option.
gcc/c-family/ChangeLog:
* c.opt: Add -stdlib= option and enumerations for
libstdc++ and libc++.
gcc/cp/ChangeLog:
* g++spec.c (LIBCXX, LIBCXX_PROFILE, LIBCXX_STATIC): New.
(LIBCXXABI, LIBCXXABI_PROFILE, LIBCXXABI_STATIC): New.
(enum stdcxxlib_kind): New.
(lang_specific_driver): Allow selection amongst multiple
c++ runtime libraries.
---
gcc/Makefile.in | 6
gcc/c-family/c.opt | 14 +
gcc/config.in | 6
gcc/configure | 57 --
gcc/configure.ac| 44 +++
gcc/cp/g++spec.c| 74 -
gcc/cppdefault.c| 5 +++
gcc/cppdefault.h| 7 -
gcc/doc/invoke.texi | 10 ++
gcc/incpath.c | 6 ++--
10 files changed, 216 insertions(+), 13 deletions(-)
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 178e4eaa513..6847022f108 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -679,6 +679,9 @@ build_tooldir = $(exec_prefix)/$(target_noncanonical)
# Directory in which the compiler finds target-independent g++ includes.
gcc_gxx_include_dir = @gcc_gxx_include_dir@
gcc_gxx_include_dir_add_sysroot = @gcc_gxx_include_dir_add_sysroot@
+# Directory in which the compiler finds libc++ includes.
+gcc_gxx_libcxx_include_dir = @gcc_gxx_libcxx_include_dir@
+gcc_gxx_libcxx_include_dir_add_sysroot =
@gcc_gxx_libcxx_include_dir_add_sysroot@
# Directory to
