Commit Graph

963 Commits

Author SHA1 Message Date
Kostya Serebryany
50fb618b93 [sanitizer-coverage] implement -fsanitize-coverage=no-prune,... instead of a hidden -mllvm flag. clang part.
llvm-svn: 302320
2017-05-05 23:28:18 +00:00
Yuka Takahashi
5511fc2eb3 Revert rL301998: "Fix a bug that -isysroot is completely ignored on Unix"
This reverts commit because it broke
sanitizer-x86_64-linux-autoconf bot and
clang-ppc64be-linux-multistage  bot.

llvm-svn: 302000
2017-05-03 06:02:45 +00:00
Yuka Takahashi
79d310713a Fix a bug that -isysroot is completely ignored on Unix
-isysroot is the flag which set the system root directory.
This bug report https://bugs.llvm.org//show_bug.cgi?id=11503
shows that -isysroot is not handled at all on Unix, so fixed this bug.

After this diff, I could get this result https://pastebin.com/TeCmn9mj .

Differential Revision: https://reviews.llvm.org/D31495

llvm-svn: 301998
2017-05-03 04:58:39 +00:00
Richard Smith
f74d946624 Move functionality for handling module maps as inputs from the -emit-module
action to the general FrontendAction infrastructure.

This permits applying -E, -ast-dump, -fsyntax-only, and so on to a module map
compilation. (The -E form is not currently especially useful yet as there's no
good way to take the output and use it to actually build a module.)

In order to support this, -cc1 now accepts -x <lang>-module-map in all cases
where it accepts -x <lang> for a language we can parse (not ir/ast). And for
uniformity, we also accept -x <lang>-header for all such languages (we used
to reject for cuda and renderscript), and -x <lang>-cpp-output for all such
languages (we used to reject for c, cl, and renderscript).

(None of these new alternatives are accepted by the driver yet, so no
user-visible changes.)

llvm-svn: 301610
2017-04-28 01:49:42 +00:00
Richard Smith
8c8fb80490 Improve diagnostics for bad -std= flag.
Don't list deprecated -std= values (c++0x etc). Only produce one line of output
per standard, even if we know it by multiple names.

In passing, add missing -std=gnu++03 alias (supported by GCC), and add new
spelling '-std=cl1.0' for OpenCL 1.0 for consistency with the other values,
with the same meaning as the preexisting '-std=cl'.

llvm-svn: 301507
2017-04-27 01:17:05 +00:00
Richard Smith
6379cfc553 Remove unnecessary and somewhat inaccurate "C89" flag from language standards.
llvm-svn: 301500
2017-04-26 23:49:57 +00:00
Richard Smith
b0fe70451e Don't accept -std= values that would switch us to a different source language.
We already prohibited this in most cases (in r130710), but had some bugs in our
enforcement of this rule. Specifically, this prevents the following
combinations:

 * -x c -std=clN.M, which would previously effectively act as if -x cl were
   used, despite the input being a C source file. (-x cl -std=cNN continues
   to be disallowed.)

 * -x c++ -std=cuda, which would previously select C++98 + CUDA, despite that
   not being a C++ standard. (-x cuda -std=c++NN is still permitted, and
   selects CUDA with the given C++ standard as its base language.
   -x cuda -std=cuda is still supported with the meaning of CUDA + C++98.)

 * -x renderscript -std=c++NN, which would previously form a hybrid "C++ with
   RenderScript extensions" language. We could support such a thing, but
   shouldn't do so by accident.

llvm-svn: 301497
2017-04-26 23:44:33 +00:00
Richard Smith
40c0efa515 Refactor frontend InputKind to prepare for treating module maps as a distinct kind of input.
No functionality change intended.

llvm-svn: 301442
2017-04-26 18:57:40 +00:00
David Blaikie
8150355498 Move Split DWARF handling to an MC option/command line argument rather than using metadata
Since Split DWARF needs to name the actual .dwo file that is generated,
it can't be known at the time the llvm::Module is produced as it may be
merged with other Modules before the object is generated and that object
may be generated with any name.

By passing the Split DWARF file name when LLVM is producing object code
the .dwo file name in the object file can match correctly.

The support for Split DWARF for implicit modules remains the same -
using metadata to store the dwo name and dwo id so that potentially
multiple skeleton CUs referring to different dwo files can be generated
from one llvm::Module.

llvm-svn: 301063
2017-04-21 23:35:36 +00:00
Alex Lorenz
1be800c511 Add support for editor placeholders to Clang
This commit teaches Clang to recognize editor placeholders that are produced
when an IDE like Xcode inserts a code-completion result that includes a
placeholder. Now when the lexer sees a placeholder token, it emits an
'editor placeholder in source file' error and creates an identifier token
that represents the placeholder. The parser/sema can now recognize the
placeholders and can suppress the diagnostics related to the placeholders. This
ensures that live issues in an IDE like Xcode won't get spurious diagnostics
related to placeholders.

This commit also adds a new compiler option named '-fallow-editor-placeholders'
that silences the 'editor placeholder in source file' error. This is useful
for an IDE like Xcode as we don't want to display those errors in live issues.

rdar://31581400

Differential Revision: https://reviews.llvm.org/D32081

llvm-svn: 300667
2017-04-19 08:58:56 +00:00
Richard Smith
34e485f922 [modules-ts] Fold together -x c++ and -x c++-module at -cc1 level.
The driver needs to know whether it's building a module interface or
implementation unit because it affects which outputs it produces and how it
builds the command pipeline. But the frontend doesn't need to know and should
not care: all it needs to know is what action it is being asked to perform on
the input.

(This is in preparation for permitting -emit-obj to be used on a module
interface unit to produce object code without going via a "full" PCM file.)

llvm-svn: 300611
2017-04-18 21:55:37 +00:00
Bruno Cardoso Lopes
c69f9f3530 [Modules] Enable local submodule visibility for ObjC/C
Remove the restriction where this is only valid with C++

rdar://problem/29055656

Differential Revision: https://reviews.llvm.org/D31781

llvm-svn: 300108
2017-04-12 21:46:16 +00:00
David Blaikie
f63556d8b4 Modular Codegen: Separate flags for function and debug info support
This allows using and testing these two features separately. (noteably,
debug info is, so far as I know, always a win (basically). But function
modular codegen is currently a loss for highly optimized code - where
most of the linkonce_odr definitions are optimized away, so providing
weak_odr definitions is only overhead)

llvm-svn: 300104
2017-04-12 20:58:33 +00:00
Bruno Cardoso Lopes
69cdc901f0 [Modules] Remove darwin specific code to check for SystemVersion.plist
This isn't need anymore and modules options -fbuild-session-file and
-fmodules-validate-once-per-build-session already provide a sane
mechanism to validate the system headers.

rdar://problem/19767523

llvm-svn: 300027
2017-04-12 04:49:00 +00:00
Jin-Gu Kang
e7cdcdea73 Preserve vec3 type.
Summary: Preserve vec3 type with CodeGen option.

Reviewers: Anastasia, bruno

Reviewed By: Anastasia

Subscribers: bruno, ahatanak, cfe-commits

Differential Revision: https://reviews.llvm.org/D30810

llvm-svn: 299445
2017-04-04 16:40:25 +00:00
Davide Italiano
1a3665bb82 [Driver] Don't crash on invalid values of -mrelocation-model=.
This is handled in a similar way we handle invalid -mcode-model.

PR: 31840
llvm-svn: 299315
2017-04-01 21:07:07 +00:00
Dean Michael Berris
504fc2262a [XRay][clang] Fix the -fxray-instruction-threshold flag processing
Summary:
The refactoring introduced a regression in the flag processing for
-fxray-instruction-threshold which causes it to not get passed properly.
This change should restore the previous behaviour.

Reviewers: rnk, pelikan

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D31491

llvm-svn: 299126
2017-03-30 22:46:45 +00:00
Dean Michael Berris
835832d37a [XRay] Add -fxray-{always,never}-instrument= flags to clang
Summary:
The -fxray-always-instrument= and -fxray-never-instrument= flags take
filenames that are used to imbue the XRay instrumentation attributes
using a whitelist mechanism (similar to the sanitizer special cases
list). We use the same syntax and semantics as the sanitizer blacklists
files in the implementation.

As implemented, we respect the attributes that are already defined in
the source file (i.e. those that have the
[[clang::xray_{always,never}_instrument]] attributes) before applying
the always/never instrument lists.

Reviewers: rsmith, chandlerc

Subscribers: jfb, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D30388

llvm-svn: 299041
2017-03-30 00:29:36 +00:00
Adam Nemet
049a31d53d Use FPContractModeKind universally
FPContractModeKind is the codegen option flag which is already ternary (off,
on, fast).  This makes it universally the type for the contractable info
across the front-end:

* In FPOptions (i.e. in the Sema + in the expression nodes).
* In LangOpts::DefaultFPContractMode which is the option that initializes
FPOptions in the Sema.

Another way to look at this change is that before fp-contractable on/off were
the only states handled to the front-end:
 * For "on", FMA folding was performed by  the front-end
 * For "fast", we simply forwarded the flag to TargetOptions to handle it in
 LLVM

Now off/on/fast are all exposed because for fast we will generate
fast-math-flags during CodeGen.

This is toward moving fp-contraction=fast from an LLVM TargetOption to a
FastMathFlag in order to fix PR25721.

---
This is a recommit of r299027 with an adjustment to the test
CodeGenCUDA/fp-contract.cu.  The test assumed that even
though -ffp-contract=on is passed FE-based folding of FMA won't happen.

This is obviously wrong since the user is asking for this explicitly with the
option.  CUDA is different that -ffp-contract=fast is on by default.

The test used to "work" because contract=fast and contract=on were maintained
separately and we didn't fold in the FE because contract=fast was on due to
the target-default.  This patch consolidates the contract=on/fast/off state
into a ternary state hence the change in behavior.
---

Differential Revision: https://reviews.llvm.org/D31167

llvm-svn: 299033
2017-03-29 21:54:24 +00:00
Adam Nemet
e940f358c8 Revert "Use FPContractModeKind universally"
This reverts commit r299027.

It's causing a test failure in clang's CodeGenCUDE/fp-contract.cu

llvm-svn: 299029
2017-03-29 21:24:19 +00:00
Adam Nemet
32093a1c28 Use FPContractModeKind universally
FPContractModeKind is the codegen option flag which is already ternary (off,
on, fast).  This makes it universally the type for the contractable info
across the front-end:

* In FPOptions (i.e. in the Sema + in the expression nodes).
* In LangOpts::DefaultFPContractMode which is the option that initializes
FPOptions in the Sema.

Another way to look at this change is that before fp-contractable on/off were
the only states handled to the front-end:
 * For "on", FMA folding was performed by  the front-end
 * For "fast", we simply forwarded the flag to TargetOptions to handle it in
 LLVM

Now off/on/fast are all exposed because for fast we will generate
fast-math-flags during CodeGen.

This is toward moving fp-contraction=fast from an LLVM TargetOption to a
FastMathFlag in order to fix PR25721.

Differential Revision: https://reviews.llvm.org/D31167

llvm-svn: 299027
2017-03-29 20:39:49 +00:00
Egor Churaev
45c26ee0bf [OpenCL] Extended mapping of parcing CodeGen arguments
Summary: Enable cl_mad_enamle and cl_no_signed_zeros options when user turns on cl_unsafe_math_optimizations or cl_fast_relaxed_math options.

Reviewers: Anastasia, cfe-commits

Reviewed By: Anastasia

Subscribers: bader, yaxunl

Differential Revision: https://reviews.llvm.org/D31324

llvm-svn: 298838
2017-03-27 10:38:01 +00:00
Anastasia Stulova
671db7027c [OpenCL][Bug 10573] Don't set CXXOperatorNames flag
The flag CXXOperatorNames was overwritten unconditionally
after being set for OpenCL. 

There seems to be no necessity to set it, so removing the line.

llvm-svn: 298709
2017-03-24 16:43:51 +00:00
Teresa Johnson
488d1dc0ed [ThinLTO] Clang support for emitting minimized bitcode for thin link
Summary:
Clang companion patch to LLVM patch D31027, which adds support
for emitting minimized bitcode file for use in the thin link step.
Add a cc1 option -fthin-link-bitcode=<file> to trigger this behavior.

Depends on D31027.

Reviewers: mehdi_amini, pcc

Subscribers: cfe-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31050

llvm-svn: 298639
2017-03-23 19:47:49 +00:00
Eric Christopher
758aad76d8 Remove the -faltivec alias option and replace it with -maltivec everywhere.
The alias was only ever used on darwin and had some issues there,
and isn't used in practice much. Also fixes a problem with -mno-altivec
not turning off -maltivec.

Also add a diagnostic for faltivec/fno-altivec that directs users to use
maltivec options and include the altivec.h file explicitly.

llvm-svn: 298449
2017-03-21 22:06:18 +00:00
Adrian Prantl
0ebdeac13a Canonicalize the path provided by -fmodules-cache-path.
This fixes lookup mismatches that could happen when the module cache
path contained a '/./' component.

<rdar://problem/30413458>

Differential Revision: https://reviews.llvm.org/D30915

llvm-svn: 297790
2017-03-14 23:07:49 +00:00
Duncan P. N. Exon Smith
60fa28882e Modules: Use hash of PCM content for SIGNATURE
Change ASTFileSignature from a random 32-bit number to the hash of the
PCM content.

  - Move definition ASTFileSignature to Basic/Module.h so Module and
    ASTSourceDescriptor can use it.

  - Change the signature from uint64_t to std::array<uint32_t,5>.

  - Stop using (saving/reading) the size and modification time of PCM
    files when there is a valid SIGNATURE.

  - Add UNHASHED_CONTROL_BLOCK, and use it to store the SIGNATURE record
    and other records that shouldn't affect the hash.  Because implicit
    modules reuses the same file for multiple levels of -Werror, this
    includes DIAGNOSTIC_OPTIONS and DIAG_PRAGMA_MAPPINGS.

This helps to solve a PCH + implicit Modules dependency issue: PCH files
are handled by the external build system, whereas implicit modules are
handled by internal compiler build system.  This prevents invalidating a
PCH when the compiler overwrites a PCM file with the same content
(modulo the diagnostic differences).

Design and original patch by Manman Ren!

llvm-svn: 297655
2017-03-13 18:45:08 +00:00
Jonas Devlieghere
5eb9c81d82 [Linker] Provide callback for internalization
Differential Revision: https://reviews.llvm.org/D30738

llvm-svn: 297649
2017-03-13 18:08:11 +00:00
Alex Lorenz
e39fa57d35 Add -iframeworkwithsysroot compiler option
This commit adds support for a new -iframeworkwithsysroot compiler option which
allows the user to specify a framework path that can be prefixed with the
sysroot. This option is similar to the -iwithsysroot option that exists to
supplement -isystem.

rdar://21316352

Differential Revision: https://reviews.llvm.org/D30183

llvm-svn: 297614
2017-03-13 11:17:41 +00:00
Richard Smith
3a36ac1af5 Add -cc1 flag -ast-dump-all to perform an AST dump including entities that haven't yet been deserialized.
llvm-svn: 297412
2017-03-09 22:00:01 +00:00
Paul Robinson
18c12d534d [PS4] Set our default dialect to C++11. NFC for other targets.
Reapplies r296209 now that r296549 has fixed what really seems to be
the last problematic test.

llvm-svn: 296554
2017-03-01 01:01:10 +00:00
Argyrios Kyrtzidis
7b5d910c66 Add a cc1 flag for setting the existing Preprocessor option 'AllowPCHWithCompilerErrors'.
llvm-svn: 296306
2017-02-27 02:06:18 +00:00
Paul Robinson
4032785206 Revert r296209, still one more test to go.
llvm-svn: 296216
2017-02-25 00:50:34 +00:00
Paul Robinson
7c344cf2b7 [PS4] Set our default dialect to C++11. NFC for other targets.
llvm-svn: 296209
2017-02-25 00:15:45 +00:00
Richard Smith
222b30b9d3 Stop asserting when a meaningless -std= flag is passed for a non-compilation
input kind; go back to silently ignoring the flag.

llvm-svn: 295122
2017-02-14 23:41:38 +00:00
Richard Smith
c91daf1cf9 [Driver] Report available language standards on user error
In case user did not provide valid standard name for -std option, available
values (with short description) will be reported.

Patch by Paweł Żukowski!

llvm-svn: 295113
2017-02-14 22:44:20 +00:00
Amjad Aboud
546bc1103b [DebugInfo] Added support to Clang FE for generating debug info for preprocessor macros.
Added "-fdebug-macro" flag (and "-fno-debug-macro" flag) to enable (and to disable) emitting macro debug info.
Added CC1 "-debug-info-macro" flag that enables emitting macro debug info.

Differential Revision: https://reviews.llvm.org/D16135

llvm-svn: 294637
2017-02-09 22:07:24 +00:00
Nirav Dave
0c86ccf4b4 [X86] Teach Clang about -mfentry flag
Replace mcount calls with calls to fentry.

Reviewers: hfinkel, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28001

llvm-svn: 293649
2017-01-31 17:00:35 +00:00
David Blaikie
9ffe5a3525 Prototype of modules codegen
First pass at generating weak definitions of inline functions from module files
(& skipping (-O0) or emitting available_externally (optimizations)
definitions where those modules are used).

External functions defined in modules are emitted into the modular
object file as well (this may turn an existing ODR violation (if that
module were imported into multiple translations) into valid/linkable
code).

Internal symbols (static functions, for example) are not correctly
supported yet. The symbol will be produced, internal, in the modular
object - unreferenceable from the users.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D28845

llvm-svn: 293456
2017-01-30 05:00:26 +00:00
Justin Lebar
b080b630b1 [CodeGen] [CUDA] Add the ability set default attrs on functions in linked modules.
Summary:
Now when you ask clang to link in a bitcode module, you can tell it to
set attributes on that module's functions to match what we would have
set if we'd emitted those functions ourselves.

This is particularly important for fast-math attributes in CUDA
compilations.

Each CUDA compilation links in libdevice, a bitcode library provided by
nvidia as part of the CUDA distribution.  Without this patch, if we have
a user-function F that is compiled with -ffast-math that calls a
function G from libdevice, F will have the unsafe-fp-math=true (etc.)
attributes, but G will have no attributes.

Since F calls G, the inliner will merge G's attributes into F's.  It
considers the lack of an unsafe-fp-math=true attribute on G to be
tantamount to unsafe-fp-math=false, so it "merges" these by setting
unsafe-fp-math=false on F.

This then continues up the call graph, until every function that
(transitively) calls something in libdevice gets unsafe-fp-math=false
set, thus disabling fastmath in almost all CUDA code.

Reviewers: echristo

Subscribers: hfinkel, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D28538

llvm-svn: 293097
2017-01-25 21:29:48 +00:00
Dehao Chen
b3a70de753 Add -fdebug-info-for-profiling to emit more debug info for sample pgo profile collection
Summary:
SamplePGO uses profile with debug info to collect profile. Unlike the traditional debugging purpose, sample pgo needs more accurate debug info to represent the profile. We add -femit-accurate-debug-info for this purpose. It can be combined with all debugging modes (-g, -gmlt, etc). It makes sure that the following pieces of info is always emitted:

* start line of all subprograms
* linkage name of all subprograms
* standalone subprograms (functions that has neither inlined nor been inlined)

The impact on speccpu2006 binary size (size increase comparing with -g0 binary, also includes data for -g binary, which does not change with this patch):

               -gmlt(orig) -gmlt(patched) -g
433.milc       4.68%       5.40%          19.73%
444.namd       8.45%       8.93%          45.99%
447.dealII     97.43%      115.21%        374.89%
450.soplex     27.75%      31.88%         126.04%
453.povray     21.81%      26.16%         92.03%
470.lbm        0.60%       0.67%          1.96%
482.sphinx3    5.77%       6.47%          26.17%
400.perlbench  17.81%      19.43%         73.08%
401.bzip2      3.73%       3.92%          12.18%
403.gcc        31.75%      34.48%         122.75%
429.mcf        0.78%       0.88%          3.89%
445.gobmk      6.08%       7.92%          42.27%
456.hmmer      10.36%      11.25%         35.23%
458.sjeng      5.08%       5.42%          14.36%
462.libquantum 1.71%       1.96%          6.36%
464.h264ref    15.61%      16.56%         43.92%
471.omnetpp    11.93%      15.84%         60.09%
473.astar      3.11%       3.69%          14.18%
483.xalancbmk  56.29%      81.63%         353.22%
geomean        15.60%      18.30%         57.81%

Debug info size change for -gmlt binary with this patch:

433.milc       13.46%
444.namd       5.35%
447.dealII     18.21%
450.soplex     14.68%
453.povray     19.65%
470.lbm        6.03%
482.sphinx3    11.21%
400.perlbench  8.91%
401.bzip2      4.41%
403.gcc        8.56%
429.mcf        8.24%
445.gobmk      29.47%
456.hmmer      8.19%
458.sjeng      6.05%
462.libquantum 11.23%
464.h264ref    5.93%
471.omnetpp    31.89%
473.astar      16.20%
483.xalancbmk  44.62%
geomean        16.83%

Reviewers: davidxl, andreadb, rob.lougher, dblaikie, echristo

Reviewed By: dblaikie, echristo

Subscribers: hfinkel, rob.lougher, andreadb, gbedwell, cfe-commits, probinson, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D25435

llvm-svn: 292458
2017-01-19 00:44:21 +00:00
Peter Collingbourne
1e1475ace5 Move vtable type metadata emission behind a cc1-level flag.
In ThinLTO mode, type metadata will require the module to be written as a
multi-module bitcode file, which is currently incompatible with the Darwin
linker. It is also useful to be able to enable or disable multi-module bitcode
for testing purposes. This introduces a cc1-level flag, -f{,no-}lto-unit,
which is used by the driver to enable multi-module bitcode on all but
Darwin+ThinLTO, and can also be used to enable/disable the feature manually.

Differential Revision: https://reviews.llvm.org/D28877

llvm-svn: 292448
2017-01-18 23:55:27 +00:00
David Blaikie
0aaa7625e1 unique_ptrify createDriverOptTable
llvm-svn: 291919
2017-01-13 17:34:15 +00:00
Mehdi Amini
7f873070c4 Add a cc1 option to force disabling lifetime-markers emission from clang
Summary: This intended as a debugging/development flag only.

Differential Revision: https://reviews.llvm.org/D28385

llvm-svn: 291300
2017-01-06 23:18:09 +00:00
David Blaikie
ea4395ebcd Reapply "IntrusiveRefCntPtr -> std::shared_ptr for CompilerInvocationBase and CodeCompleteConsumer"
Aleksey Shlypanikov pointed out my mistake in migrating an explicit
unique_ptr to auto - I was expecting the function returned a unique_ptr,
but instead it returned a raw pointer - introducing a leak.

Thanks Aleksey!

This reapplies r291184, reverted in r291249.

llvm-svn: 291270
2017-01-06 19:49:01 +00:00
David Blaikie
81d0829438 Revert "IntrusiveRefCntPtr -> std::shared_ptr for CompilerInvocationBase and CodeCompleteConsumer"
Caused a memory leak reported by asan. Reverting while I investigate.

This reverts commit r291184.

llvm-svn: 291249
2017-01-06 17:47:10 +00:00
David Blaikie
9280a857bc IntrusiveRefCntPtr -> std::shared_ptr for CompilerInvocationBase and CodeCompleteConsumer
llvm-svn: 291184
2017-01-05 22:19:11 +00:00
David Blaikie
61137e1a50 Use shared_ptr instead of IntrusiveRefCntPtr for ModuleFileExtension
The intrusiveness wasn't needed here, so this simplifies/clarifies the
ownership model.

llvm-svn: 291150
2017-01-05 18:23:18 +00:00
Alex Lorenz
c1608f7f69 Add -f[no-]strict-return flag that can be used to avoid undefined behaviour
in non-void functions that fall off at the end without returning a value when
compiling C++.

Clang uses the new compiler flag to determine when it should treat control flow
paths that fall off the end of a non-void function as unreachable. If
-fno-strict-return is on, the code generator emits the ureachable and trap
IR only when the function returns either a record type with a non-trivial
destructor or another non-trivially copyable type.

The primary goal of this flag is to avoid treating falling off the end of a
non-void function as undefined behaviour. The burden of undefined behaviour
is placed on the caller instead: if the caller ignores the returned value then
the undefined behaviour is avoided. This kind of behaviour is useful in
several cases, e.g. when compiling C code in C++ mode.

rdar://13102603

Differential Revision: https://reviews.llvm.org/D27163

llvm-svn: 290960
2017-01-04 13:40:34 +00:00
Richard Smith
26b86ea8b1 [c++17] Implement P0522R0 as written. This allows a template template argument
to be specified for a template template parameter whenever the parameter is at
least as specialized as the argument (when there's an obvious and correct
mapping from uses of the parameter to uses of the argument). For example, a
template with more parameters can be passed to a template template parameter
with fewer, if those trailing parameters have default arguments.

This is disabled by default, despite being a DR resolution, as it's fairly
broken in its current state: there are no partial ordering rules to cope with
template template parameters that have different parameter lists, meaning that
code that attempts to decompose template-ids based on arity can hit unavoidable
ambiguity issues.

The diagnostics produced on a non-matching argument are also pretty bad right
now, but I aim to improve them in a subsequent commit.

llvm-svn: 290792
2016-12-31 21:41:23 +00:00