Commit Graph

4555 Commits

Author SHA1 Message Date
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
Reid Kleckner 979da9a4c3 Avoid including Builtins.h in Preprocessor.h
Builtins are rarely if ever accessed via the Preprocessor. They are
typically found on the ASTContext, so there should be no performance
penalty to using a pointer indirection to store the builtin context.
2019-11-15 16:45:16 -08:00
Puyan Lotfi 79e345fbcc [clang][IFS] Adds support for more decl types in clang interface stubs.
Adding support for processing the following Decls: NonTypeTemplateParmDecl,
CXXConversionDecl, UnresolvedUsingValueDecl, UsingDecl, UsingShadowDecl,
TypeAliasTemplateDecl, TypeAliasDecl, VarTemplateDecl,
VarTemplateSpecializationDecl, UsingDirectiveDecl, TemplateTemplateParmDecl,
ClassTemplatePartialSpecializationDecl, IndirectFieldDecl.

Also, this allows for processing NamedDecls that don't have an identifier and
skips over VarDecls that are dependent on template types.

Differential Revision: https://reviews.llvm.org/D69995
2019-11-08 20:27:25 -05:00
Jan Korous d52cff8836 Revert "Reland "[clang] Report sanitizer blacklist as a dependency in cc1""
This reverts commit cae4a28864.
2019-11-08 14:28:30 -08:00
Jan Korous 555c6be041 [clang] Fix -fsanitize-system-blacklist processing in cc1 2019-11-08 13:57:33 -08:00
Jan Korous cae4a28864 Reland "[clang] Report sanitizer blacklist as a dependency in cc1"
This reverts commit 3182027282.
2019-11-08 13:55:00 -08:00
Jan Korous 6d28588cc0 Reland "[clang] Report sanitizer blacklist as a dependency in cc1"
This reverts commit 9b8413ac6e.
2019-11-08 13:54:28 -08:00
Adrian Prantl 2073dd2da7 Redeclare Objective-C property accessors inside the ObjCImplDecl in which they are synthesized.
This patch is motivated by (and factored out from)
https://reviews.llvm.org/D66121 which is a debug info bugfix. Starting
with DWARF 5 all Objective-C methods are nested inside their
containing type, and that patch implements this for synthesized
Objective-C properties.

1. SemaObjCProperty populates a list of synthesized accessors that may
   need to inserted into an ObjCImplDecl.

2. SemaDeclObjC::ActOnEnd inserts forward-declarations for all
   accessors for which no override was provided into their
   ObjCImplDecl. This patch does *not* synthesize AST function
   *bodies*. Moving that code from the static analyzer into Sema may
   be a good idea though.

3. Places that expect all methods to have bodies have been updated.

I did not update the static analyzer's inliner for synthesized
properties to point back to the property declaration (see
test/Analysis/Inputs/expected-plists/nullability-notes.m.plist), which
I believed to be more bug than a feature.

Differential Revision: https://reviews.llvm.org/D68108

rdar://problem/53782400
2019-11-08 08:23:22 -08:00
Abel Kocsis 9b8413ac6e Revert "Revert "Revert "[clang] Report sanitizer blacklist as a dependency in cc1"""
This reverts commit 3182027282.
2019-11-08 14:08:15 +01:00
Abel Kocsis 3182027282 Revert "Revert "[clang] Report sanitizer blacklist as a dependency in cc1""
This reverts commit 6b45e1bc11.
2019-11-08 14:00:44 +01:00
Jeremy Morse 6b45e1bc11 Revert "[clang] Report sanitizer blacklist as a dependency in cc1"
This reverts commit 03b84e4f6d.

This breaks dfsan tests with a linking failure, in for example this build:

  http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/24312

Reverting this patch locally makes those tests succeed.
2019-11-08 12:07:42 +00:00
Jan Korous 03b84e4f6d [clang] Report sanitizer blacklist as a dependency in cc1
Previously these were reported from the driver which blocked clang-scan-deps from getting the full set of dependencies from cc1 commands.

Also the default sanitizer blacklist that is added in driver was never reported as a dependency. I introduced -fsanitize-system-blacklist cc1 option to keep track of which blacklists were user-specified and which were added by driver and clang -MD now also reports system blacklists as dependencies.

Differential Revision: https://reviews.llvm.org/D69290
2019-11-07 14:06:43 -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
Duncan P. N. Exon Smith 8112a423a8 clang/Modules: Bring back optimization lost in 31e14f41a2
31e14f41a2 accidentally dropped caching of
failed module loads.  This brings it back by making
ModuleMap::getCachedModuleLoad return an Optional.
2019-11-04 11:40:03 -08:00
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
Duncan P. N. Exon Smith 31e14f41a2 clang/Modules: Sink CompilerInstance::KnownModules into ModuleMap
Avoid use-after-frees when FrontendAction::BeginSourceFile is called
twice on the same CompilerInstance by sinking
CompilerInstance::KnownModules into ModuleMap.  On the way, rename the
map to CachedModuleLoads.  I considered (but rejected) merging this with
ModuleMap::Modules, since that only has top-level modules and this map
includes submodules.

This is an alternative to https://reviews.llvm.org/D58497.  Thanks to
nemanjai for the detailed analysis of the problem!
2019-11-03 19:57:33 -08:00
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
Yaxun (Sam) Liu 1c98ff49a3 Fix name of warn_ignored_hip_only_option
Differential Revision: https://reviews.llvm.org/D69268
2019-10-22 16:36:28 -04:00
Yaxun (Sam) Liu 68f5ca4e19 [HIP] Add option -fgpu-allow-device-init
Add this option to allow device side class type global variables
with non-trivial ctor/dtor. device side init/fini functions will
be emitted, which will be executed by HIP runtime when
the fat binary is loaded/unloaded.

This feature is to facilitate implementation of device side
sanitizer which requires global vars with non-trival ctors.

By default this option is disabled.

Differential Revision: https://reviews.llvm.org/D69268
2019-10-22 16:06:20 -04:00
Michael J. Spencer 8896d073b1 [Implicit Modules] Add -cc1 option -fmodules-strict-context-hash which includes search paths and diagnostics.
This is a recommit of r375322 and r375327 with a fix for the Windows test breakage.

llvm-svn: 375466
2019-10-21 22:51:13 +00:00
Scott Linder 87cb734c04 [Clang] Add VerboseOutputStream to CompilerInstance
Remove one instance of a hardcoded output stream in
CompilerInstance::ExecuteAction. There are still other cases of output
being hard-coded to standard streams in ExecuteCompilerInvocation, but
this patch covers the case when no flags like -version or -help are
passed, namely the "X warnings and Y errors generated." diagnostic.

Differential Revision: https://reviews.llvm.org/D53768

llvm-svn: 375442
2019-10-21 19:04:56 +00:00
Bjorn Pettersson 78424e5f84 Prune include of DataLayout.h from include/clang/Basic/TargetInfo.h. NFC
Summary:
Use a forward declaration of DataLayout instead of including
DataLayout.h in clangs TargetInfo.h. This reduces include
dependencies toward DataLayout.h (and other headers such as
DerivedTypes.h, Type.h that is included by DataLayout.h).

Needed to move implemantation of TargetInfo::resetDataLayout
from TargetInfo.h to TargetInfo.cpp.

Reviewers: rnk

Reviewed By: rnk

Subscribers: jvesely, nhaehnle, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69262

llvm-svn: 375438
2019-10-21 17:58:14 +00:00
Michael J. Spencer 81a01e73fa Revert "[Implicit Modules] Add -cc1 option -fmodules-strict-context-hash which includes search paths and diagnostics." and "[Docs] Fix header level."
The test doesn't work on Windows. I'll fix it and recommit later.

llvm-svn: 375338
2019-10-19 09:45:28 +00:00
Michael J. Spencer 14a3f77ba1 [Implicit Modules] Add -cc1 option -fmodules-strict-context-hash which includes search paths and diagnostics.
Differential Revision: https://reviews.llvm.org/D68528

llvm-svn: 375322
2019-10-19 01:36:37 +00:00
Richard Smith 974c8b7e2f [c++20] Add rewriting from comparison operators to <=> / ==.
This adds support for rewriting <, >, <=, and >= to a normal or reversed
call to operator<=>, for rewriting != to a normal or reversed call to
operator==, and for rewriting <=> and == to reversed forms of those same
operators.

Note that this is a breaking change for various C++17 code patterns,
including some in use in LLVM. The most common patterns (where an
operator== becomes ambiguous with a reversed form of itself) are still
accepted under this patch, as an extension (with a warning). I'm hopeful
that we can get the language rules fixed before C++20 ships, and the
extension warning is aimed primarily at providing data to inform that
decision.

llvm-svn: 375306
2019-10-19 00:04:43 +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
Volodymyr Sapsai 930ada91ce Replace platform-dependent `stat` with `llvm::sys::fs::status`. NFC intended.
Reviewers: bruno, sammccall

Reviewed By: sammccall

Subscribers: jkorous, dexonsmith, arphaman, ributzka, cfe-commits

Differential Revision: https://reviews.llvm.org/D69011

llvm-svn: 375031
2019-10-16 19:12:34 +00:00
Simon Pilgrim b150494fc7 RewriteModernObjC - silence static analyzer getAs<> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.

llvm-svn: 374991
2019-10-16 10:50:06 +00:00
Saar Raz 5d98ba6077 [Concepts] Concept Specialization Expressions
Part of C++20 Concepts implementation effort. Added Concept Specialization Expressions that are created when a concept is refe$

D41217 on Phabricator.

(recommit after fixing failing Parser test on windows)

llvm-svn: 374903
2019-10-15 15:24:26 +00:00
Nico Weber b4638f9ff0 Revert 374882 "[Concepts] Concept Specialization Expressions"
This reverts commit ec87b00382.
The test fails on Windows, see e.g.
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/11533/steps/stage%201%20check/logs/stdio

Also revert follow-up r374893.

llvm-svn: 374899
2019-10-15 14:46:39 +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
Saar Raz ec87b00382 [Concepts] Concept Specialization Expressions
Part of C++20 Concepts implementation effort. Added Concept Specialization Expressions that are created when a concept is referenced with arguments, and tests thereof.

llvm-svn: 374882
2019-10-15 11:48:58 +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
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
Puyan Lotfi 76f9869bf2 [clang][IFS] Escape mangled names so MS ABI doesn't break YAML parsing.
Microsoft's ABI mangles names differently than Itanium and this breaks the LLVM
yaml parser unless the name is escaped in quotes. Quotes are being added to the
mangled names of the IFS file generation so that llvm-ifs doesn't break when
Windows triples are passed to the driver.

Differential Revision: https://reviews.llvm.org/D68915

llvm-svn: 374798
2019-10-14 18:03:03 +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
Puyan Lotfi e3388c42f3 [clang][IFS] Fixing assert in clang interface stubs for enums, records, typedefs
The clang IFS ASTConsumer was asserting on enums, records (struct definitions in
C), and typedefs. All it needs to do is skip them because the stub just needs to
expose global object instances and functions.

Differential Revision: https://reviews.llvm.org/D68859

llvm-svn: 374573
2019-10-11 17:24:11 +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
Nikola Prica f71bac6f43 [DebugInfo] Enable call site debug info for ARM and AArch64
ARM and AArch64 SelectionDAG support for tacking parameter forwarding
register is implemented so we can allow clang invocations for those two
targets.
Beside that restrict debug entry value support to be emitted for
LimitedDebugInfo info and FullDebugInfo. Other types of debug info do
not have functions nor variables debug info.

Reviewers: aprantl, probinson, dstenb, vsk

Reviewed By: vsk

Differential Revision: https://reviews.llvm.org/D67004

llvm-svn: 374153
2019-10-09 10:14:15 +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
Simon Pilgrim 8dc1700979 RewriteModernObjC - silence static analyzer getAs<> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.

llvm-svn: 373905
2019-10-07 13:58:15 +00:00
Simon Pilgrim 43bbca9228 RewriteObjC - silence static analyzer getAs<> null dereference warnings. NFCI.
The static analyzer is warning about potential null dereferences, but we should be able to use castAs<> directly and if not assert will fire for us.

llvm-svn: 373829
2019-10-05 13:42:14 +00:00
Richard Smith 772e266fbf Properly handle instantiation-dependent array bounds.
We previously failed to treat an array with an instantiation-dependent
but not value-dependent bound as being an instantiation-dependent type.
We now track the array bound expression as part of a constant array type
if it's an instantiation-dependent expression.

llvm-svn: 373685
2019-10-04 01:25:59 +00:00