Commit Graph

443 Commits

Author SHA1 Message Date
Melanie Blower 5412913631 Revert " Reapply af57dbf12e "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior=""
This reverts commit cdbed2dd85.
Build break on Windows (lit fail)
2019-12-04 12:21:23 -08:00
Melanie Blower cdbed2dd85 Reapply af57dbf12e "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
Patch was reverted because https://bugs.llvm.org/show_bug.cgi?id=44048
        The original patch is modified to set the strictfp IR attribute
        explicitly in CodeGen instead of as a side effect of IRBuilder

        Differential Revision: https://reviews.llvm.org/D62731
2019-12-04 11:32:33 -08:00
Alexandre Ganea 1abd4c94d7 [Clang] Bypass distro detection on non-Linux hosts
Skip distro detection when we're not running on Linux, or when the target triple is not Linux. This saves a few OS calls for each invocation of clang.exe.

Differential Revision: https://reviews.llvm.org/D70467
2019-11-28 17:02:06 -05:00
Nandor Licker f584f04dab [ConstExprPreter] Removed the flag forcing the use of the interpreter
Summary:
Removed the ```-fforce-experimental-new-constant-interpreter flag```, leaving
only the ```-fexperimental-new-constant-interpreter``` one. The interpreter
now always emits an error on an unsupported feature.

Allowing the interpreter to bail out would require a mapping from APValue to
interpreter memory, which will not be necessary in the final version. It is
more sensible to always emit an error if the interpreter fails.

Reviewers: jfb, Bigcheese, rsmith, dexonsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70071
2019-11-27 20:07:19 +00:00
Dan McGregor 6c92cdff72 Initial implementation of -fmacro-prefix-map and -ffile-prefix-map
GCC 8 implements -fmacro-prefix-map. Like -fdebug-prefix-map, it replaces a string prefix for the __FILE__ macro.
-ffile-prefix-map is the union of -fdebug-prefix-map and -fmacro-prefix-map

Reviewed By: rnk, Lekensteyn, maskray

Differential Revision: https://reviews.llvm.org/D49466
2019-11-26 15:17:49 -08:00
Francis Visoiu Mistrih e15b26fbbd Reland: [Remarks][Driver] Use different remark files when targeting multiple architectures
When the driver is targeting multiple architectures at once, for things
like Universal Mach-Os, we need to emit different remark files for each
cc1 invocation to avoid overwriting the files from a different
invocation.

For example:

$ clang -c -o foo.o -fsave-optimization-record -arch x86_64 -arch x86_64h

will create two remark files:

* foo-x86_64.opt.yaml
* foo-x86_64h.opt.yaml
2019-11-18 11:17:38 -08:00
Reid Kleckner 1ff5f0ced3 Revert "[Remarks][Driver] Use different remark files when targeting multiple architectures"
This reverts commit b4e2b112b5.

Test doesn't appear to pass on Windows, maybe all non-Mac.
2019-11-18 10:52:41 -08:00
Eric Christopher 30e7ee3c4b Temporarily Revert "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
and a follow-up NFC rearrangement as it's causing a crash on valid. Testcase is on the original review thread.

This reverts commits af57dbf12e and e6584b2b7b
2019-11-18 10:46:48 -08:00
Francis Visoiu Mistrih b4e2b112b5 [Remarks][Driver] Use different remark files when targeting multiple architectures
When the driver is targeting multiple architectures at once, for things
like Universal Mach-Os, we need to emit different remark files for each
cc1 invocation to avoid overwriting the files from a different
invocation.

For example:

$ clang -c -o foo.o -fsave-optimization-record -arch x86_64 -arch x86_64h

will create two remark files:

* foo-x86_64.opt.yaml
* foo-x86_64h.opt.yaml
2019-11-18 10:38:10 -08:00
Momchil Velikov aa6d48fa70 Implement target(branch-protection) attribute for AArch64
This patch implements `__attribute__((target("branch-protection=...")))`
in a manner, compatible with the analogous GCC feature:

https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes

Differential Revision: https://reviews.llvm.org/D68711
2019-11-15 15:40:46 +00:00
Tim Northover 44e5879f0f AArch64: add arm64_32 support to Clang. 2019-11-12 12:45:18 +00:00
Hans Wennborg b1ac1f0071 Revert cdcf58e5af "[RISCV] enable LTO support, pass some options to linker."
This started passing target-features on the linker line, not just for RISCV but
for all targets, leading to error messages in Chromium Android build:

  '+soft-float-abi' is not a recognized feature for this target (ignoring feature)
  '+soft-float-abi' is not a recognized feature for this target (ignoring feature)

See Phabricator review for details.

Reverting until this can be fixed properly.

> Summary:
> 1. enable LTO need to pass target feature and abi to LTO code generation
>    RISCV backend need the target feature to decide which extension used in
>    code generation.
> 2. move getTargetFeatures to CommonArgs.h and add ForLTOPlugin flag
> 3. add general tools::getTargetABI in CommonArgs.h because different target uses different
>    way to get the target ABI.
>
> Patch by Kuan Hsu Chen (khchen)
>
> Reviewers: lenary, lewis-revill, asb, MaskRay
>
> Reviewed By: lenary
>
> Subscribers: hiraditya, dschuff, aheejin, fedor.sergeev, mehdi_amini, inglorion, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, cfe-commits
>
> Tags: #clang
>
> Differential Revision: https://reviews.llvm.org/D67409
2019-11-11 10:58:39 +01:00
David Blaikie 8d8f9c2440 [clang] Add -fdebug-default-version for specifying the default DWARF version
This flag decouples specifying the DWARF version from enabling/disabling
DWARF in general (or the gN level - gmlt/limited/standalone, etc) while
still allowing existing -gdwarf-N flags to override this default.

Patch by Caroline Tice!

Differential Revision: https://reviews.llvm.org/D69822
2019-11-07 12:05:58 -08:00
Melanie Blower af57dbf12e Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior=
Add options to control floating point behavior: trapping and
    exception behavior, rounding, and control of optimizations that affect
    floating point calculations. More details in UsersManual.rst.

    Reviewers: rjmccall

    Differential Revision: https://reviews.llvm.org/D62731
2019-11-07 07:22:45 -08:00
Jonas Paulsson 9376714314 [Clang FE] Recognize -mnop-mcount CL option (SystemZ only).
Recognize -mnop-mcount from the command line and add a function attribute
"mnop-mcount"="true" when passed.

When this option is used, a nop is added instead of a call to fentry. This
is used when building the Linux Kernel.

If this option is passed for any other target than SystemZ, an error is
generated.

Review: Ulrich Weigand
https://reviews.llvm.org/D67763
2019-11-05 12:12:36 +01:00
Yaxun (Sam) Liu 4264e7bbfd [CUDA][HIP] Disable emitting llvm.linker.options in device compilation
The linker options (e.g. pragma detect_mismatch) are intended for host
compilation only, therefore disable it for device compilation.

Differential Revision: https://reviews.llvm.org/D57829
2019-11-04 23:21:39 -05:00
Amy Huang ab76cfdd20 Recommit "[CodeView] Add option to disable inline line tables."
This reverts commit 004ed2b0d1.
Original commit hash 6d03890384

Summary:
This adds a clang option to disable inline line tables. When it is used,
the inliner uses the call site as the location of the inlined function instead of
marking it as an inline location with the function location.

https://reviews.llvm.org/D67723
2019-11-04 09:15:26 -08:00
David Blaikie 098d901bd1 DebugInfo: Let -gdwarf use the toolchain default DWARF version, instead of hardcoded/aliased to -gdwarf-4 2019-11-01 15:17:51 -07:00
David Blaikie 42465f406b DebugInfo: (NFC) Refactor DWARF version calculation to make a future change (-fdebug-default-version) easier 2019-11-01 14:56:43 -07:00
David Candler 92aa0c2dbc [cfi] Add flag to always generate .debug_frame
This adds a flag to LLVM and clang to always generate a .debug_frame
section, even if other debug information is not being generated. In
situations where .eh_frame would normally be emitted, both .debug_frame
and .eh_frame will be used.

Differential Revision: https://reviews.llvm.org/D67216
2019-10-31 09:48:30 +00:00
Amy Huang 004ed2b0d1 Revert "[CodeView] Add option to disable inline line tables."
because it breaks compiler-rt tests.

This reverts commit 6d03890384.
2019-10-30 17:31:12 -07:00
Amy Huang 6d03890384 [CodeView] Add option to disable inline line tables.
Summary:
This adds a clang option to disable inline line tables. When it is used,
the inliner uses the call site as the location of the inlined function instead of
marking it as an inline location with the function location.

See https://bugs.llvm.org/show_bug.cgi?id=42344

Reviewers: rnk

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D67723
2019-10-30 16:52:39 -07:00
Andrew Paverd d157a9bc8b Add Windows Control Flow Guard checks (/guard:cf).
Summary:
A new function pass (Transforms/CFGuard/CFGuard.cpp) inserts CFGuard checks on
indirect function calls, using either the check mechanism (X86, ARM, AArch64) or
or the dispatch mechanism (X86-64). The check mechanism requires a new calling
convention for the supported targets. The dispatch mechanism adds the target as
an operand bundle, which is processed by SelectionDAG. Another pass
(CodeGen/CFGuardLongjmp.cpp) identifies and emits valid longjmp targets, as
required by /guard:cf. This feature is enabled using the `cfguard` CC1 option.

Reviewers: thakis, rnk, theraven, pcc

Subscribers: ychen, hans, metalcanine, dmajor, tomrittervg, alex, mehdi_amini, mgorny, javed.absar, kristof.beyls, hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65761
2019-10-28 15:19:39 +00:00
Michael Liao 5a48678a6a [hip] Allow the declaration of functions with variadic arguments in HIP.
Summary:
- As variadic parameters have the lowest rank in overload resolution,
  without real usage of `va_arg`, they are commonly used as the
  catch-all fallbacks in SFINAE. As the front-end still reports errors
  on calls to `va_arg`, the declaration of functions with variadic
  arguments should be allowed in general.

Reviewers: jlebar, tra, yaxunl

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69389
2019-10-25 00:39:24 -04:00
Yuanfang Chen ef7a154d17 [clang][ThinLTO] Promote cc1 -fthin_link_bitcode to driver -fthinlto_link_bitcode
Summary:
A necessary step to let build system caching work for its output.

Reviewers: tejohnson, steven_wu

Reviewed by: tejohnson

Subscribers: mehdi_amini, inglorion, dexonsmith, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69406
2019-10-24 16:54:45 -07:00
evgeny 1ae8e8d25f Don't add -fsplit-lto-unit for thin LTO builds with PS4 and Darwin toolchains
These toolchains use legacy thin LTO API, which is not capable of unit splitting
Differential revision: https://reviews.llvm.org/D69173
2019-10-24 14:10:03 +03:00
Eugene Leviant bc887a8d4a [ThinLTOCodeGenerator] Add support for index-based WPD
This is clang part of the patch. It adds -flto-unit flag for thin LTO
builds on Mac and PS4

Differential revision: https://reviews.llvm.org/D68950

llvm-svn: 375224
2019-10-18 11:58:21 +00:00
Oliver Stannard 3b598b9c86 Reland: Dead Virtual Function Elimination
Remove dead virtual functions from vtables with
replaceNonMetadataUsesWith, so that CGProfile metadata gets cleaned up
correctly.

Original commit message:

Currently, it is hard for the compiler to remove unused C++ virtual
functions, because they are all referenced from vtables, which are referenced
by constructors. This means that if the constructor is called from any live
code, then we keep every virtual function in the final link, even if there
are no call sites which can use it.

This patch allows unused virtual functions to be removed during LTO (and
regular compilation in limited circumstances) by using type metadata to match
virtual function call sites to the vtable slots they might load from. This
information can then be used in the global dead code elimination pass instead
of the references from vtables to virtual functions, to more accurately
determine which functions are reachable.

To make this transformation safe, I have changed clang's code-generation to
always load virtual function pointers using the llvm.type.checked.load
intrinsic, instead of regular load instructions. I originally tried writing
this using clang's existing code-generation, which uses the llvm.type.test
and llvm.assume intrinsics after doing a normal load. However, it is possible
for optimisations to obscure the relationship between the GEP, load and
llvm.type.test, causing GlobalDCE to fail to find virtual function call
sites.

The existing linkage and visibility types don't accurately describe the scope
in which a virtual call could be made which uses a given vtable. This is
wider than the visibility of the type itself, because a virtual function call
could be made using a more-visible base class. I've added a new
!vcall_visibility metadata type to represent this, described in
TypeMetadata.rst. The internalization pass and libLTO have been updated to
change this metadata when linking is performed.

This doesn't currently work with ThinLTO, because it needs to see every call
to llvm.type.checked.load in the linkage unit. It might be possible to
extend this optimisation to be able to use the ThinLTO summary, as was done
for devirtualization, but until then that combination is rejected in the
clang driver.

To test this, I've written a fuzzer which generates random C++ programs with
complex class inheritance graphs, and virtual functions called through object
and function pointers of different types. The programs are spread across
multiple translation units and DSOs to test the different visibility
restrictions.

I've also tried doing bootstrap builds of LLVM to test this. This isn't
ideal, because only classes in anonymous namespaces can be optimised with
-fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not
work correctly with -fvisibility=hidden. However, there are only 12 test
failures when building with -fvisibility=hidden (and an unmodified compiler),
and this change does not cause any new failures for either value of
-fvisibility.

On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size
reduction of ~6%, over a baseline compiled with "-O2 -flto
-fvisibility=hidden -fwhole-program-vtables". The best cases are reductions
of ~14% in 450.soplex and 483.xalancbmk, and there are no code size
increases.

I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which
show a geomean size reduction of ~3%, again with no size increases.

I had hoped that this would have no effect on performance, which would allow
it to awlays be enabled (when using -fwhole-program-vtables). However, the
changes in clang to use the llvm.type.checked.load intrinsic are causing ~1%
performance regression in the C++ parts of SPEC2006. It should be possible to
recover some of this perf loss by teaching optimisations about the
llvm.type.checked.load intrinsic, which would make it worth turning this on
by default (though it's still dependent on -fwhole-program-vtables).

Differential revision: https://reviews.llvm.org/D63932

llvm-svn: 375094
2019-10-17 09:58:57 +00:00
Sergey Dmitriev 5836c356fa [Clang][OpenMP Offload] Move offload registration code to the wrapper
The final list of OpenMP offload targets becomes known only at the link time and since offload registration code depends on the targets list it makes sense to delay offload registration code generation to the link time instead of adding it to the host part of every fat object. This patch moves offload registration code generation from clang to the offload wrapper tool.

This is the last part of the OpenMP linker script elimination patch https://reviews.llvm.org/D64943

Differential Revision: https://reviews.llvm.org/D68746

llvm-svn: 374937
2019-10-15 18:42:47 +00:00
Jan Korous f8907fa6f4 Reland [Driver] Fix -working-directory issues
Don't change the default VFS in Driver, update tests & reland.

This reverts commit 999f8a7416.

llvm-svn: 374926
2019-10-15 17:51:59 +00:00
Bruno Cardoso Lopes 1731fc88d1 Reapply: [Modules][PCH] Hash input files content
Summary:
When files often get touched during builds, the mtime based validation
leads to different problems in implicit modules builds, even when the
content doesn't actually change:

- Modules only: module invalidation due to out of date files. Usually causing rebuild traffic.
- Modules + PCH: build failures because clang cannot rebuild a module if it comes from building a PCH.
- PCH: build failures because clang cannot rebuild a PCH in case one of the input headers has different mtime.

This patch proposes hashing the content of input files (headers and
module maps), which is performed during serialization time. When looking
at input files for validation, clang only computes the hash in case
there's a mtime mismatch.

I've tested a couple of different hash algorithms availble in LLVM in
face of building modules+pch for `#import <Cocoa/Cocoa.h>`:
- `hash_code`: performace diff within the noise, total module cache increased by 0.07%.
- `SHA1`: 5% slowdown. Haven't done real size measurements, but it'd be BLOCK_ID+20 bytes per input file, instead of BLOCK_ID+8 bytes from `hash_code`.
- `MD5`: 3% slowdown. Like above, but BLOCK_ID+16 bytes per input file.

Given the numbers above, the patch uses `hash_code`. The patch also
improves invalidation error msgs to point out which type of problem the
user is facing: "mtime", "size" or "content".

rdar://problem/29320105

Reviewers: dexonsmith, arphaman, rsmith, aprantl

Subscribers: jkorous, cfe-commits, ributzka

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67249

> llvm-svn: 374841

llvm-svn: 374895
2019-10-15 14:23:55 +00:00
Jorge Gorbe Moya b052331bd6 Revert "Dead Virtual Function Elimination"
This reverts commit 9f6a873268.

llvm-svn: 374844
2019-10-14 23:25:25 +00:00
Eric Christopher 3be9169caa Temporarily Revert [Modules][PCH] Hash input files content
as it's breaking a few bots.

This reverts r374841 (git commit 2a1386c81d)

llvm-svn: 374842
2019-10-14 23:14:24 +00:00
Bruno Cardoso Lopes 2a1386c81d [Modules][PCH] Hash input files content
Summary:
When files often get touched during builds, the mtime based validation
leads to different problems in implicit modules builds, even when the
content doesn't actually change:

- Modules only: module invalidation due to out of date files. Usually causing rebuild traffic.
- Modules + PCH: build failures because clang cannot rebuild a module if it comes from building a PCH.
- PCH: build failures because clang cannot rebuild a PCH in case one of the input headers has different mtime.

This patch proposes hashing the content of input files (headers and
module maps), which is performed during serialization time. When looking
at input files for validation, clang only computes the hash in case
there's a mtime mismatch.

I've tested a couple of different hash algorithms availble in LLVM in
face of building modules+pch for `#import <Cocoa/Cocoa.h>`:
- `hash_code`: performace diff within the noise, total module cache increased by 0.07%.
- `SHA1`: 5% slowdown. Haven't done real size measurements, but it'd be BLOCK_ID+20 bytes per input file, instead of BLOCK_ID+8 bytes from `hash_code`.
- `MD5`: 3% slowdown. Like above, but BLOCK_ID+16 bytes per input file.

Given the numbers above, the patch uses `hash_code`. The patch also
improves invalidation error msgs to point out which type of problem the
user is facing: "mtime", "size" or "content".

rdar://problem/29320105

Reviewers: dexonsmith, arphaman, rsmith, aprantl

Subscribers: jkorous, cfe-commits, ributzka

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67249

llvm-svn: 374841
2019-10-14 23:02:03 +00:00
Jian Cai 4ec5205da7 Add support to -Wa,-W in clang
Summary:
Currently clang does not support -Wa,-W, which suppresses warning
messages in GNU assembler. Add this option for gcc compatibility.
https://bugs.llvm.org/show_bug.cgi?id=43651. Reland with differential
information.

Reviewers: bcain

Reviewed By: bcain

Subscribers: george.burgess.iv, gbiv, llozano, manojgupta, nickdesaulniers, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68884

llvm-svn: 374834
2019-10-14 22:28:03 +00:00
Jian Cai 89478148d8 Revert "Add support to -Wa,-W in clang"
This reverts commit e72eeca43b9577be2aae55f7603febbf223a6ab3.

llvm-svn: 374833
2019-10-14 22:28:01 +00:00
Jian Cai 753d789c44 Add support to -Wa,-W in clang
Currently clang does not support -Wa,-W, which suppresses warning
messages in GNU assembler. Add this option for gcc compatibility.
https://bugs.llvm.org/show_bug.cgi?id=43651

llvm-svn: 374822
2019-10-14 21:21:39 +00:00
Jan Korous c5d14b5c6f [clang-scan-deps] Support for clang --analyze in clang-scan-deps
The goal is to have 100% fidelity in clang-scan-deps behavior when
--analyze is present in compilation command.

At the same time I don't want to break clang-tidy which expects
__static_analyzer__ macro defined as built-in.

I introduce new cc1 options (-setup-static-analyzer) that controls
the macro definition and is conditionally set in driver.

Differential Revision: https://reviews.llvm.org/D68093

llvm-svn: 374815
2019-10-14 20:15:01 +00:00
Sam Elliott cdcf58e5af [RISCV] enable LTO support, pass some options to linker.
Summary:
1. enable LTO need to pass target feature and abi to LTO code generation
   RISCV backend need the target feature to decide which extension used in
   code generation.
2. move getTargetFeatures to CommonArgs.h and add ForLTOPlugin flag
3. add general tools::getTargetABI in CommonArgs.h because different target uses different
   way to get the target ABI.

Patch by Kuan Hsu Chen (khchen)

Reviewers: lenary, lewis-revill, asb, MaskRay

Reviewed By: lenary

Subscribers: hiraditya, dschuff, aheejin, fedor.sergeev, mehdi_amini, inglorion, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67409

llvm-svn: 374774
2019-10-14 14:00:13 +00:00
Puyan Lotfi 17bde36a03 [clang][IFS] Fixing spelling errors in interface-stubs OPT flag (NFC).
This is just a long standing spelling error that was found recently.

llvm-svn: 374638
2019-10-12 06:25:07 +00:00
Oliver Stannard 9f6a873268 Dead Virtual Function Elimination
Currently, it is hard for the compiler to remove unused C++ virtual
functions, because they are all referenced from vtables, which are referenced
by constructors. This means that if the constructor is called from any live
code, then we keep every virtual function in the final link, even if there
are no call sites which can use it.

This patch allows unused virtual functions to be removed during LTO (and
regular compilation in limited circumstances) by using type metadata to match
virtual function call sites to the vtable slots they might load from. This
information can then be used in the global dead code elimination pass instead
of the references from vtables to virtual functions, to more accurately
determine which functions are reachable.

To make this transformation safe, I have changed clang's code-generation to
always load virtual function pointers using the llvm.type.checked.load
intrinsic, instead of regular load instructions. I originally tried writing
this using clang's existing code-generation, which uses the llvm.type.test
and llvm.assume intrinsics after doing a normal load. However, it is possible
for optimisations to obscure the relationship between the GEP, load and
llvm.type.test, causing GlobalDCE to fail to find virtual function call
sites.

The existing linkage and visibility types don't accurately describe the scope
in which a virtual call could be made which uses a given vtable. This is
wider than the visibility of the type itself, because a virtual function call
could be made using a more-visible base class. I've added a new
!vcall_visibility metadata type to represent this, described in
TypeMetadata.rst. The internalization pass and libLTO have been updated to
change this metadata when linking is performed.

This doesn't currently work with ThinLTO, because it needs to see every call
to llvm.type.checked.load in the linkage unit. It might be possible to
extend this optimisation to be able to use the ThinLTO summary, as was done
for devirtualization, but until then that combination is rejected in the
clang driver.

To test this, I've written a fuzzer which generates random C++ programs with
complex class inheritance graphs, and virtual functions called through object
and function pointers of different types. The programs are spread across
multiple translation units and DSOs to test the different visibility
restrictions.

I've also tried doing bootstrap builds of LLVM to test this. This isn't
ideal, because only classes in anonymous namespaces can be optimised with
-fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not
work correctly with -fvisibility=hidden. However, there are only 12 test
failures when building with -fvisibility=hidden (and an unmodified compiler),
and this change does not cause any new failures for either value of
-fvisibility.

On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size
reduction of ~6%, over a baseline compiled with "-O2 -flto
-fvisibility=hidden -fwhole-program-vtables". The best cases are reductions
of ~14% in 450.soplex and 483.xalancbmk, and there are no code size
increases.

I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which
show a geomean size reduction of ~3%, again with no size increases.

I had hoped that this would have no effect on performance, which would allow
it to awlays be enabled (when using -fwhole-program-vtables). However, the
changes in clang to use the llvm.type.checked.load intrinsic are causing ~1%
performance regression in the C++ parts of SPEC2006. It should be possible to
recover some of this perf loss by teaching optimisations about the
llvm.type.checked.load intrinsic, which would make it worth turning this on
by default (though it's still dependent on -fwhole-program-vtables).

Differential revision: https://reviews.llvm.org/D63932

llvm-svn: 374539
2019-10-11 11:59:55 +00:00
Reid Kleckner 5e866e411c Add -fgnuc-version= to control __GNUC__ and other GCC macros
I noticed that compiling on Windows with -fno-ms-compatibility had the
side effect of defining __GNUC__, along with __GNUG__, __GXX_RTTI__, and
a number of other macros for GCC compatibility. This is undesirable and
causes Chromium to do things like mix __attribute__ and __declspec,
which doesn't work. We should have a positive language option to enable
GCC compatibility features so that we can experiment with
-fno-ms-compatibility on Windows. This change adds -fgnuc-version= to be
that option.

My issue aside, users have, for a long time, reported that __GNUC__
doesn't match their expectations in one way or another. We have
encouraged users to migrate code away from this macro, but new code
continues to be written assuming a GCC-only environment. There's really
nothing we can do to stop that. By adding this flag, we can allow them
to choose their own adventure with __GNUC__.

This overlaps a bit with the "GNUMode" language option from -std=gnu*.
The gnu language mode tends to enable non-conforming behaviors that we'd
rather not enable by default, but the we want to set things like
__GXX_RTTI__ by default, so I've kept these separate.

Helps address PR42817

Reviewed By: hans, nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D68055

llvm-svn: 374449
2019-10-10 21:04:25 +00:00
Sergey Dmitriev a0d83768f1 [Clang][OpenMP Offload] Add new tool for wrapping offload device binaries
This patch removes the remaining part of the OpenMP offload linker scripts which was used for inserting device binaries into the output linked binary. Device binaries are now inserted into the host binary with a help of the wrapper bit-code file which contains device binaries as data. Wrapper bit-code file is dynamically created by the clang driver with a help of new tool clang-offload-wrapper which takes device binaries as input and produces bit-code file with required contents. Wrapper bit-code is then compiled to an object and resulting object is appended to the host linking by the clang driver.

This is the second part of the patch for eliminating OpenMP linker script (please see https://reviews.llvm.org/D64943).

Differential Revision: https://reviews.llvm.org/D68166

llvm-svn: 374219
2019-10-09 20:42:58 +00:00
Simon Atanasyan 60db8b7946 [mips] Set default float ABI to "soft" on FreeBSD
Initial patch by Kyle Evans.

Fix PR43596

llvm-svn: 374154
2019-10-09 10:38:03 +00:00
Puyan Lotfi c382d03ca8 [clang][ifs] Clang Interface Stubs ToolChain plumbing.
Second Landing Attempt:

This patch enables end to end support for generating ELF interface stubs
directly from clang. Now the following:

clang -emit-interface-stubs -o libfoo.so a.cpp b.cpp c.cpp

will product an ELF binary with visible symbols populated. Visibility attributes
and -fvisibility can be used to control what gets populated.

* Adding ToolChain support for clang Driver IFS Merge Phase
* Implementing a default InterfaceStubs Merge clang Tool, used by ToolChain
* Adds support for the clang Driver to involve llvm-ifs on ifs files.
* Adds -emit-merged-ifs flag, to tell llvm-ifs to emit a merged ifs text file
  instead of the final object format (normally ELF)


Differential Revision: https://reviews.llvm.org/D63978

llvm-svn: 374061
2019-10-08 15:23:14 +00:00
Nico Weber 6713f8235b Revert 373538 and follow-ups 373549 and 373552.
They break tests on (at least) macOS.

llvm-svn: 373556
2019-10-03 02:38:43 +00:00
Puyan Lotfi 406de17b9b [clang][ifs] Clang Interface Stubs ToolChain plumbing.
This patch enables end to end support for generating ELF interface stubs
directly from clang. Now the following:

clang -emit-interface-stubs -o libfoo.so a.cpp b.cpp c.cpp

will product an ELF binary with visible symbols populated. Visibility attributes
and -fvisibility can be used to control what gets populated.

* Adding ToolChain support for clang Driver IFS Merge Phase
* Implementing a default InterfaceStubs Merge clang Tool, used by ToolChain
* Adds support for the clang Driver to involve llvm-ifs on ifs files.
* Adds -emit-merged-ifs flag, to tell llvm-ifs to emit a merged ifs text file
  instead of the final object format (normally ELF)


Differential Revision: https://reviews.llvm.org/D63978

llvm-svn: 373538
2019-10-02 22:50:07 +00:00
Teresa Johnson dca5b94e79 [ThinLTO] Enable index-only WPD from clang
Summary:
To trigger the index-only Whole Program Devirt support added to LLVM, we
need to be able to specify -fno-split-lto-unit in conjunction with
-fwhole-program-vtables. Keep the default for -fwhole-program-vtables as
-fsplit-lto-unit, but don't error on that option combination.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68029

llvm-svn: 373370
2019-10-01 18:08:29 +00:00
Hans Wennborg 362345769a Fix the 'directory' field in DumpCompilationDatabase and add test
This broke in r371027 due to a missing negation
(llvm::sys::fs::current_path returns false on success).

llvm-svn: 373049
2019-09-27 08:14:45 +00:00
Reid Kleckner e440d23195 Only pass -coverage-notes-file when emitting coverage
The only functional change here is that -coverage-notes-file is not
passed to -cc1 in some situations.

This code appears to be trying to put the gcno and gcda output next to
the final object file, but it's doing that in a really convoluted way
that needs to be re-examined. It looks for -c or -S in the original
command, and then looks at the -o argument if present in order to handle
the -fno-integrated-as case. However, this doesn't work if this is a
link command with multiple inputs. I looked into fixing this, but the
check-profile test suite has a lot of dependencies on this behavior, so
I left it all alone.

llvm-svn: 373004
2019-09-26 18:13:19 +00:00