149 Commits

Author SHA1 Message Date
serge-sans-paille
38818b60c5
Move from llvm::makeArrayRef to ArrayRef deduction guides - llvm/ part
Use deduction guides instead of helper functions.

The only non-automatic changes have been:

1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).

Per reviewers' comment, some useless makeArrayRef have been removed in the process.

This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.

Differential Revision: https://reviews.llvm.org/D140955
2023-01-05 14:11:08 +01:00
serge-sans-paille
d9ab3e82f3
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.

The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.

Differential Revision: https://reviews.llvm.org/D139881
2022-12-27 09:55:19 +01:00
Vitaly Buka
aa171833ab Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4 (part 2)"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4"

GCC build hangs on this bot https://lab.llvm.org/buildbot/#/builders/37/builds/19104
compiling CMakeFiles/obj.clangBasic.dir/Targets/AArch64.cpp.d

The bot uses GNU 11.3.0, but I can reproduce locally with gcc (Debian 12.2.0-3) 12.2.0.

This reverts commit caa713559bd38f337d7d35de35686775e8fb5175.
This reverts commit 06b90e2e9c991e211fecc97948e533320a825470.
This reverts commit e953ae5bbc313fd0cc980ce021d487e5b5199ea4.
2022-12-25 23:12:47 -08:00
serge-sans-paille
e953ae5bbc
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This is a recommit of 719d98dfa841c522d8d452f0685e503538415a53 that into
account a GGC issue (probably
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92181) when dealing with
intiailizer_list and constant expressions.

Workaround this by avoiding initializer list, at the expense of a
temporary plain old array.

Differential Revision: https://reviews.llvm.org/D139881
2022-12-24 10:25:06 +01:00
serge-sans-paille
07d9ab9aa5
Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
There are still remaining issues with GCC 12, see for instance

https://lab.llvm.org/buildbot/#/builders/93/builds/12669

This reverts commit 5ce4e92264102de21760c94db9166afe8f71fcf6.
2022-12-23 13:29:21 +01:00
serge-sans-paille
5ce4e92264
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This is a recommit of 719d98dfa841c522d8d452f0685e503538415a53 with a
change to llvm/utils/TableGen/OptParserEmitter.cpp to cope with GCC bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108158

Differential Revision: https://reviews.llvm.org/D139881
2022-12-23 12:48:17 +01:00
serge-sans-paille
b7065a31b5
Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Failing builds: https://lab.llvm.org/buildbot#builders/9/builds/19030
This is GCC specific and has been reported upstream: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108158

This reverts commit 719d98dfa841c522d8d452f0685e503538415a53.
2022-12-23 11:36:56 +01:00
serge-sans-paille
719d98dfa8
[clang] Use a StringRef instead of a raw char pointer to store builtin and call information
This avoids recomputing string length that is already known at compile
time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

Differential Revision: https://reviews.llvm.org/D139881
2022-12-23 10:31:47 +01:00
serge-sans-paille
7aa9b335d6
Use range based loop to iterate over OptTable::PrefixesUnion
And sneak in a small storage optimization of OptTable::PrefixChars
2022-12-16 15:12:31 +01:00
serge-sans-paille
a14c3ac4a9
[NFC] Finish cleaning up StringRef usage in OptTable::ParseOneArg
This is a followup to https://reviews.llvm.org/D139274
2022-12-09 11:55:42 +01:00
serge-sans-paille
138942c833
Recommit of 8ae18303f97d5dcfaecc90b4d87effb2011ed82e - part 2
Differential Revision: https://reviews.llvm.org/D139274
2022-12-09 10:41:34 +01:00
serge-sans-paille
d881fdf720
Revert "Recommit of 8ae18303f97d5dcfaecc90b4d87effb2011ed82e - part 2"
This reverts commit 4faf00006cf989f3ae212912994022c0486a2dc4.
2022-12-09 10:15:41 +01:00
serge-sans-paille
4faf00006c
Recommit of 8ae18303f97d5dcfaecc90b4d87effb2011ed82e - part 2
Differential Revision: https://reviews.llvm.org/D139274
2022-12-09 10:07:02 +01:00
serge-sans-paille
40ade845be
Revert "Store OptTable::Info::Name as a StringRef"
Another revert, for another set of issues I don't reproduce locally...

see https://lab.llvm.org/buildbot/#/builders/139/builds/32327

This reverts commit bdfa3100dc3ea9e9ce4d3d4100ea6bb4c3fa2b81.
2022-12-07 17:29:53 +01:00
serge-sans-paille
bdfa3100dc
Store OptTable::Info::Name as a StringRef
This is a recommit of 8ae18303f97d5dcfaecc90b4d87effb2011ed82e,
with a few cleanups.

This avoids implicit conversion to StringRef at several points, which in
turns avoid redundant calls to strlen.

As a side effect, this greatly simplifies the implementation of
StrCmpOptionNameIgnoreCase.

It also eventually gives a consistent, humble speedup in compilation
time (timing updated since original commit).

https://llvm-compile-time-tracker.com/compare.php?from=76fcfea283472a80356d87c89270b0e2d106b54c&to=b70eb1f347f22fe4d2977360c4ed701eabc43994&stat=instructions:u

Differential Revision: https://reviews.llvm.org/D139274
2022-12-07 16:32:37 +01:00
Kazu Hirata
405fc404bf [ADT] Don't including None.h (NFC)
These source files no longer use None, so they do not need to include
None.h.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-06 20:14:51 -08:00
Douglas Yung
4857b6f8ff Revert "Store OptTable::Info::Name as a StringRef"
This reverts commit 5951b0bb23f3265bea16f28c2af9d278b9d829c6.

This is causing 24 test failures on the PS4 linux bot: https://lab.llvm.org/buildbot/#/builders/139/builds/32263
2022-12-06 19:37:05 -08:00
serge-sans-paille
5951b0bb23
Store OptTable::Info::Name as a StringRef
This is a recommit of 8ae18303f97d5dcfaecc90b4d87effb2011ed82e,
with a few cleanups.

This avoids implicit conversion to StringRef at several points, which in
turns avoid redundant calls to strlen.

As a side effect, this greatly simplifies the implementation of
StrCmpOptionNameIgnoreCase.

It also eventually gives a consistent, humble speedup in compilation
time (timing updated since original commit).

https://llvm-compile-time-tracker.com/compare.php?from=de4b6a1bc64db33643f001ad45fae7b92b4a4688&to=c23a93d1292052b4be2fbe8c586fa31143d0c7ed&stat=instructions:u

Differential Revision: https://reviews.llvm.org/D139274
2022-12-06 22:51:28 +01:00
Nico Weber
de4b6a1bc6 Revert "Store OptTable::Info::Name as a StringRef"
This reverts commit 8ae18303f97d5dcfaecc90b4d87effb2011ed82e.
Breaks buildling lldb, see https://reviews.llvm.org/D139274#3974171
2022-12-06 08:43:48 -05:00
serge-sans-paille
8ae18303f9
Store OptTable::Info::Name as a StringRef
This avoids implicit conversion to StringRef at several points, which in
turns avoid redundant calls to strlen.

As a side effect, this greatly simplifies the implementation of
StrCmpOptionNameIgnoreCase.

It also eventually gives a consistent, humble speedup in compilation
time.

https://llvm-compile-time-tracker.com/compare.php?from=5f5b942823474e98e43a27d515a87ce140396c53&to=60e13b778119fc32d50dc38ff1a564a87146e9c6&stat=instructions:u

Differential Revision: https://reviews.llvm.org/D139274
2022-12-06 14:10:07 +01:00
Kazu Hirata
aadaaface2 [llvm] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 21:11:44 -08:00
Kazu Hirata
0e9d37ff95 [llvm] Qualify auto in range-based for loops (NFC) 2022-08-28 23:29:00 -07:00
Fangrui Song
de9d80c1c5 [llvm] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.
2022-08-08 11:24:15 -07:00
Fangrui Song
aefa4b60ce [Driver] Simplify hasFlag pattern with addOptInFlag/addOptOutFlag helpers
Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D123468
2022-04-11 12:29:25 -07:00
Kazu Hirata
ccdd5bb2c2 [llvm] Use range-based for loops (NFC) 2021-12-09 09:37:29 -08:00
Kazu Hirata
262dd1e42d [llvm] Use range-based for loops (NFC) 2021-12-02 09:27:47 -08:00
Nico Weber
7664508910 [llvm/OptTable] Add named param comment for GroupedShortOption 2021-09-27 11:33:29 -04:00
Nico Weber
730bbc6f72 [llvm/OptTable] Drop "The" prefix on fields 2021-09-27 11:24:51 -04:00
Nico Weber
6ffd8e3902 [llvm] Convert OptTable::ParseOneArg() to std::unique_ptr<> 2021-09-27 11:19:21 -04:00
Nico Weber
7789a68e5a [llvm] Convert OptTable::parseOneArgGrouped() to std::unique_ptr<> 2021-09-27 11:19:15 -04:00
Nico Weber
2f955424c4 [llvm] ConvertOption::accept(), acceptInternal() to std::unique_ptr<>
These functions transfer ownership to the caller. Make this clear in the
type system.

No behavior change.
2021-09-27 11:05:02 -04:00
gbreynoo
e28cd75a50 [OptTable] Reapply Improve error message output for grouped short options
This reapplies 71d7fed3bc2ad6c22729d446526a59fcfd99bd03 which was
reverted by 3e2bd82f02c6cbbfb0544897c7645867f04b3a7e. This change
includes the fix for breaking the sanitizer bots.

As seen in https://bugs.llvm.org/show_bug.cgi?id=48880 the current
implementation for parsing grouped short options can return unclear
error messages. This change fixes the example given in the ticket in
which a flag is incorrectly given an argument. Also when parsing a
group we now keep reading past the first incorrect option and output
errors for all incorrect options in the group.

Differential Revision: https://reviews.llvm.org/D108770
2021-09-03 11:13:52 +01:00
Kevin Athey
3e2bd82f02 Revert "[OptTable] Improve error message output for grouped short options"
This reverts commit 71d7fed3bc2ad6c22729d446526a59fcfd99bd03.

Reason: broke sanitizer bots
more info: https://reviews.llvm.org/D108770
2021-08-31 14:06:11 -07:00
gbreynoo
71d7fed3bc [OptTable] Improve error message output for grouped short options
As seen in https://bugs.llvm.org/show_bug.cgi?id=48880 the current
implementation for parsing grouped short options can return unclear
error messages. This change fixes the example given in the ticket in
which a flag is incorrectly given an argument. Also when parsing a
group we now keep reading past the first incorrect option and output
errors for all incorrect options in the group.

Differential Revision: https://reviews.llvm.org/D108770
2021-08-31 16:41:08 +01:00
Andrzej Warzynski
dcc6b7b1d5 [OptTable] Refine how printHelp treats empty help texts
Currently, `printHelp` behaves differently for options that:
  * do not define `HelpText` (such options _are not printed_), and
  * define its `HelpText` as `HelpText<"">` (such options _are printed_).
In practice, both approaches lead to no help text and `printHelp` should
treat them consistently. This patch addresses that by making
`printHelpt` check the length of the help text to be printed.

All affected tests have been updated accordingly. The option definitions
for llvm-cvtres have been updated with a short description or "Not
  implemented" for options that are ignored by the tool.

Differential Revision: https://reviews.llvm.org/D107557
2021-08-19 09:30:15 +00:00
Fangrui Song
f1e2d5851b [OptTable] Rename PrintHelp to printHelp
To be consistent with other member functions and match the coding standard.
2021-06-24 14:47:03 -07:00
Martin Storsjö
42f74e8249 [llvm] Rename StringRef _lower() method calls to _insensitive()
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
2021-06-25 00:22:01 +03:00
Jan Svoboda
43cac1d27d [clang][cli] NFC: Remove ArgList infrastructure for recording queries
This patch removes the infrastructure for recording queries in `ArgList`, partially reverting D94472.

The infrastructure was used during command line round-trip to determine which arguments should a certain subset of `CompilerInvocation` generate.

Since D96280, the command line arguments are being generated all at once, making this code no longer necessary.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D96325
2021-02-25 13:53:24 +01:00
Jan Svoboda
225ccf0c50 [clang][cli] Command line round-trip for HeaderSearch options
This patch implements generation of remaining header search arguments.
It's done manually in C++ as opposed to TableGen, because we need the flexibility and don't anticipate reuse.

This patch also tests the generation of header search options via a round-trip. This way, the code gets exercised whenever Clang is built and tested in asserts mode. All `check-clang` tests pass.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D94472
2021-02-04 10:18:34 +01:00
Kazu Hirata
e5b4dbab04 [llvm] Simplify string comparisons (NFC)
Identified with readability-string-compare.
2021-01-11 18:48:09 -08:00
Aditya Kumar
c4e327a960 Remove memory allocation with string
Differential Revision: https://reviews.llvm.org/D92506
2020-12-05 15:14:44 -08:00
serge-sans-paille
9218ff50f9 llvmbuildectomy - replace llvm-build by plain cmake
No longer rely on an external tool to build the llvm component layout.

Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.

These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.

Differential Revision: https://reviews.llvm.org/D90848
2020-11-13 10:35:24 +01:00
Andrzej Warzynski
4eed800b18 [NFC] Fix the signature and definition of findByPrefix
In https://reviews.llvm.org/rG257b29715bb27b7d9f6c3c40c481b6a4af0b37e5,
the definition of OptTable::Info::Flags was changed from `unsigned
short` to `unsigned int`, but the definition/declaration of
OptTable::findByPrefix wasn't updated to reflect that.

This patch updates findByPrefix accordingly.
2020-09-11 12:38:28 +01:00
Nadav Rotem
d54c252bc8 [Clang options] Optimize optionMatches() runtime by removing mallocs
The method optionMatches() constructs 9865 std::string instances when comparing different
options. Many of these instances exceed the size of the internal storage and force memory
allocations. This patch adds an early exit check that eliminates most of the string allocations
while keeping the code simple.

Example inputs:
Prefix: /, Name: Fr
Prefix: -, Name: Fr
Prefix: -, Name: fsanitize-address-field-padding=
Prefix: -, Name: fsanitize-address-globals-dead-stripping
Prefix: -, Name: fsanitize-address-poison-custom-array-cookie
Prefix: -, Name: fsanitize-address-use-after-scope
Prefix: -, Name: fsanitize-address-use-odr-indicator
Prefix: -, Name: fsanitize-blacklist=

Differential Revision: D85538
2020-08-12 23:07:07 -07:00
Fangrui Song
593e196297 [llvm-symbolizer] Switch command line parsing from llvm::cl to OptTable
for the advantage outlined by D83639 ([OptTable] Support grouped short options)

Some behavior changes:

* -i={0,false} is removed. Use --no-inlines instead.
* --demangle={0,false} is removed. Use --no-demangle instead
* -untag-addresses={0,false} is removed. Use --no-untag-addresses instead

Added a higher level API OptTable::parseArgs which handles optional
initial options populated from an environment variable, expands response
files recursively, and parses options.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83530
2020-08-04 08:53:15 -07:00
Fangrui Song
f8a29b174a [OptTable] Support grouped short options
POSIX.1-2017 12.2 Utility Syntax Guidelines, Guideline 5 says:

> One or more options without option-arguments, followed by at most one option that takes an option-argument, should be accepted when grouped behind one '-' delimiter.

i.e. -abc represents -a -b -c. The grouped short options are very common.  Many
utilities extend the syntax by allowing (an option with an argument) following a
sequence of short options.

This patch adds the support to OptTable, similar to cl::Group for CommandLine
(D58711).  llvm-symbolizer will use the feature (D83530). CommandLine is exotic
in some aspects. OptTable is preferred if the user wants to get rid of the
behaviors.

* `cl::opt<bool> i(...)` can be disabled via -i=false or -i=0, which is
  different from conventional --no-i.
* Handling --foo & --no-foo requires a comparison of argument positions,
  which is a bit clumsy in user code.

OptTable::parseOneArg (non-const reference InputArgList) is added along with
ParseOneArg (const ArgList &). The duplicate does not look great at first
glance. However, The implementation can be simpler if ArgList is mutable.
(ParseOneArg is used by clang-cl (FlagsToInclude/FlagsToExclude) and lld COFF
(case-insensitive). Adding grouped short options can make the function even more
complex.)

The implementation allows a long option following a group of short options. We
probably should refine the code to disallow this in the future. Allowing this
seems benign for now.

Reviewed By: grimar, jhenderson

Differential Revision: https://reviews.llvm.org/D83639
2020-07-17 09:32:43 -07:00
Benjamin Kramer
adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Tom Stellard
ab411801b8 [cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"
Summary:
Most libraries are defined in the lib/ directory but there are also a
few libraries defined in tools/ e.g. libLLVM, libLTO.  I'm defining
"Component Libraries" as libraries defined in lib/ that may be included in
libLLVM.so.  Explicitly marking the libraries in lib/ as component
libraries allows us to remove some fragile checks that attempt to
differentiate between lib/ libraries and tools/ libraires:

1. In tools/llvm-shlib, because
llvm_map_components_to_libnames(LIB_NAMES "all") returned a list of
all libraries defined in the whole project, there was custom code
needed to filter out libraries defined in tools/, none of which should
be included in libLLVM.so.  This code assumed that any library
defined as static was from lib/ and everything else should be
excluded.

With this change, llvm_map_components_to_libnames(LIB_NAMES, "all")
only returns libraries that have been added to the LLVM_COMPONENT_LIBS
global cmake property, so this custom filtering logic can be removed.
Doing this also fixes the build with BUILD_SHARED_LIBS=ON
and LLVM_BUILD_LLVM_DYLIB=ON.

2. There was some code in llvm_add_library that assumed that
libraries defined in lib/ would not have LLVM_LINK_COMPONENTS or
ARG_LINK_COMPONENTS set.  This is only true because libraries
defined lib lib/ use LLVMBuild.txt and don't set these values.
This code has been fixed now to check if the library has been
explicitly marked as a component library, which should now make it
easier to remove LLVMBuild at some point in the future.

I have tested this patch on Windows, MacOS and Linux with release builds
and the following combinations of CMake options:

- "" (No options)
- -DLLVM_BUILD_LLVM_DYLIB=ON
- -DLLVM_LINK_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_LINK_LLVM_DYLIB=ON

Reviewers: beanz, smeenai, compnerd, phosek

Reviewed By: beanz

Subscribers: wuzish, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, mgorny, mehdi_amini, sbc100, jgravelle-google, hiraditya, aheejin, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, dang, Jim, lenary, s.egerton, pzheng, sameer.abuasal, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70179
2019-11-21 10:48:08 -08:00
Jonas Devlieghere
0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Nico Weber
e3f06b478c Let unaliased Args track which Alias they were created from, and use that in Arg::getAsString() for diagnostics
With this, `clang-cl /source-charset:utf-16 test.cc` now prints `invalid
value 'utf-16' in '/source-charset:utf-16'` instead of `invalid value
'utf-16' in '-finput-charset=utf-16'` before, and several other clang-cl
flags produce much less confusing output as well.

Fixes PR29106.

Since an arg and its alias can have different arg types (joined vs not)
and different values (because of AliasArgs<>), I chose to give the Alias
its own Arg object. For convenience, I just store the alias directly in
the unaliased arg – there aren't many arg objects at runtime, so that
seems ok.

Finally, I changed Arg::getAsString() to use the alias's representation
if it's present – that function was already documented as being the
suitable function for diagnostics, and most callers already used it for
diagnostics.

Implementation-wise, Arg::accept() previously used to parse things as
the unaliased option. The core of that switch is now extracted into a
new function acceptInternal() which parses as the _aliased_ option, and
the previously-intermingled unaliasing is now done as an explicit step
afterwards.

(This also changes one place in lld that didn't use getAsString() for
diagnostics, so that that one place now also prints the flag as the user
wrote it, not as it looks after it went through unaliasing.)

Differential Revision: https://reviews.llvm.org/D64253

llvm-svn: 365413
2019-07-09 00:34:08 +00:00