This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
This is a re-commit of
fc30901096,
a571f82a50,
64c045e25b, and
de6ddaeef3,
and reverts aa643f455a.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
Revert "Fixup D123950 to address revert of D123345"
This reverts commit aa643f455a.
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
This is a re-commit of
fc30901096,
a571f82a50, and
64c045e25b
which were reverted in
e75d8b7037
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
Although we moved to Github Issues. The bug report message refers to
Bugzilla still. This patch tries to update these URLs.
Reviewed By: MaskRay, Quuxplusone, jhenderson, libunwind, libc++
Differential Revision: https://reviews.llvm.org/D116351
Adds link/code sample to avoid rendering two dashes as non-ASCII "en dash".
Also make wording a complete sentence.
Reviewed By: nickdesaulniers, tmfink
Differential Revision: https://reviews.llvm.org/D85596
Fixes pr/11710.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Resubmit after breaking Windows and OSX builds.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D80242
If -Wl,object_path_lto,<lto-filename>.o is not passed at link time
when compiling and linking in separate steps with -flto and -g, the
temporary file used for Link Time Optimization is deleted by the linker,
so the executable is missing debug symbols and can't be easily debugged,
and dsymutil can't be run.
Document this behaviour.
Differential revision: https://reviews.llvm.org/D82733
This patch broke the Sanitizer buildbots. Please see the commit's
differential revision for more information
(https://reviews.llvm.org/D67678).
This reverts commit b72a8c65e4.
Add constraints for the test that require specific backend targets
to be registered.
Remove trailing whitespace in the doc.
Differential Revision: https://reviews.llvm.org/D63105
llvm-svn: 363475
This patch allows clang users to print out a list of supported CPU models using
clang [--target=<target triple>] --print-supported-cpus
Then, users can select the CPU model to compile to using
clang --target=<triple> -mcpu=<model> a.c
It is a handy feature to help cross compilation.
llvm-svn: 363464
Summary:
This updates all places in documentation that refer to "Mac OS X", "OS X", etc.
to instead use the modern name "macOS" when no specific version number is
mentioned.
If a specific version is mentioned, this attempts to use the OS name at the time
of that version:
* Mac OS X for 10.0 - 10.7
* OS X for 10.8 - 10.11
* macOS for 10.12 - present
Reviewers: JDevlieghere
Subscribers: mgorny, christof, arphaman, cfe-commits, lldb-commits, libcxx-commits, llvm-commits
Tags: #clang, #lldb, #libc, #llvm
Differential Revision: https://reviews.llvm.org/D62654
llvm-svn: 362113
Although not very well known, diagtool is an incredibly convenient
utility for dealing with diagnostics.
Particularly useful are the "tree" and "show-enabled" commands:
- The former prints the hierarchy of diagnostic (warning) flags and
which of them are enabled by default.
- The latter can be used to replace an invocation to clang and will
print which diagnostics are disabled, warnings or errors.
For instance: `diagtool show-enabled -Wall -Werror /tmp/test.c` will
print that -Wunused-variable (warn_unused_variable) will be treated as
an error.
This patch adds them to the install target so it gets shipped with the
LLVM release. It also adds a very basic man page and mentions this
change in the release notes.
Differential revision: https://reviews.llvm.org/D46694
llvm-svn: 332448
Summary:
After a remark on a FreeBSD mailing list that the clang man page did
not have any list of possible values for the `-std=` flag, I have now
attempted to exhaustively list those, for each available language.
I also documented the default standard for each language, if there was
more than one choice.
Reviewers: rsmith, dexonsmith, sylvestre.ledru, mgorny
Reviewed By: rsmith
Subscribers: fhahn, emaste, cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D45406
llvm-svn: 329827
As a first step toward removing Objective-C garbage collection from
Clang, remove support from the driver. I'm hoping this will flush out
any expected bots/configurations/whatever that might rely on it.
I've left the options behind temporarily in -cc1 to keep tests passing.
I'll kill them off entirely in a follow up when I've had a chance to
update/delete the rest of Clang.
llvm-svn: 288872
Summary:
Just like gcc, we should have the -Og option as more and more software are using it:
https://llvm.org/bugs/show_bug.cgi?id=20765
Reviewers: echristo, dberlin, dblaikie, keith.walker.arm, rengolin
Subscribers: aprantl, friss, mehdi_amini, RKSimon, probinson, majnemer, cfe-commits
Differential Revision: https://reviews.llvm.org/D24998
llvm-svn: 286602
Make the -print-libgcc-file-name option print an appropriate compiler
runtime library, that is libgcc.a if gcc runtime is used
and an appropriate compiler-rt library if that runtime is used.
The main use for this is to allow linking executables built with
-nodefaultlibs (e.g. to avoid linking to the standard C++ library) to
the compiler runtime library, e.g. using:
clang++ ... -nodefaultlibs $(clang++ ... -print-libgcc-file-name)
in which case currently a program built like this linked to the gcc
runtime unconditionally. The patch fixes it to use compiler-rt libraries
instead when compiler-rt is the active runtime.
Differential Revision: https://reviews.llvm.org/D25338
llvm-svn: 283746
Revert the -print-libgcc-file-name change as the new test fails
on Darwin. It needs to be updated to run the libgcc part only on systems
supporting that rtlib.
llvm-svn: 283586
Make the -print-libgcc-file-name option print an appropriate compiler
runtime library, that is libgcc.a if gcc runtime is used
and an appropriate compiler-rt library if that runtime is used.
The main use for this is to allow linking executables built with
-nodefaultlibs (e.g. to avoid linking to the standard C++ library) to
the compiler runtime library, e.g. using:
clang++ ... -nodefaultlibs $(clang++ ... -print-libgcc-file-name)
in which case currently a program built like this linked to the gcc
runtime unconditionally. The patch fixes it to use compiler-rt libraries
instead when compiler-rt is the active runtime.
Differential Revision: https://reviews.llvm.org/D25338
llvm-svn: 283572
This option behaves in a similar spirit as -save-temps and writes
internal llvm statistics in json format to a file.
Differential Revision: https://reviews.llvm.org/D24820
llvm-svn: 282426
The fix in r282148 was not enough to fix the following error:
/home/llvmbb/llvm-build-dir/clang-sphinx-docs/llvm/src/tools/clang/docs/CommandGuide/clang.rst:338:
WARNING: unknown option: -flto=full
on the sphinx bot:
http://lab.llvm.org:8011/builders/clang-sphinx-docs/builds/16313
(not reproducible locally).
This time, simply remove the option reference.
llvm-svn: 282151
Summary: Add some user facing documentation on ThinLTO and how to use it.
Reviewers: mehdi_amini
Subscribers: mehdi_amini, cfe-commits
Differential Revision: https://reviews.llvm.org/D24806
llvm-svn: 282089
This patch adds an entry for "-rtlib" in the output of `man clang` and `clang -help`.
Patch by Lei Zhang!
Differential Revision: https://reviews.llvm.org/D24069
llvm-svn: 281440
to enable the use of external type references in the debug info
(a.k.a. module debugging).
The driver expands -gmodules to "-g -fmodule-format=obj -dwarf-ext-refs"
and passes that to cc1. All this does at the moment is set a flag
codegenopts.
http://reviews.llvm.org/D11958
llvm-svn: 246192
Summary:
This diff introduces .rst files, Sphinx config, and a CMake target
for building clang man pages. This will deprecate the existing .pod-
based man page, and will integrate nicely with CMake. This diff does
not remove the existing man page; that will be done in a follow-up
once packagers have had a chance to react to the change.
For now, only clang(1) has been done; others can be added over time
by dropping additional files into the docs/CommandGuide directory.
The index page for CommandGuide has been copied from LLVM's
docs/CommandGuide.
The man page itself is mostly the same, with a few minor cosmetic
changes. The only major change is the SYNOPSIS section. I was unable
to get .rst/Sphinx produce the same style as in the existing man page.
Instead, I changed it to match the LLVM tools' relatively simple style.
To build the man pages, use the "docs-clang-man" target if building
with CMake. Otherwise, use "make -f Makefile.sphinx man".
Reviewers: cmatthews, silvas
Subscribers: dim, gaeke, beanz, cfe-commits
Differential Revision: http://reviews.llvm.org/D10562
llvm-svn: 241037
Richard Smith