Commit Graph

1476 Commits

Author SHA1 Message Date
Ivan Donchevskii 13c9c05441 [clang-tidy] Remove extra config.h includes
It's included in a new header ClangTidyForceLinker.h and should not
be included the second time.

Follow up for the https://reviews.llvm.org/D55595

llvm-svn: 349132
2018-12-14 07:44:52 +00:00
Ivan Donchevskii 37512e58ba [clang-tidy] Share the forced linking code between clang-tidy tool and plugin
Extract code that forces linking to the separate header and include it in both plugin and standalone tool.
Try 2: missing header guard and "clang/Config/config.h" are added to the new header.

Differential Revision: https://reviews.llvm.org/D55595

llvm-svn: 349131
2018-12-14 07:29:06 +00:00
Stephane Moore b69ece899d [clang-tidy] Improve google-objc-function-naming diagnostics 📙
Summary:
The diagnostics from google-objc-function-naming check will be more
actionable if they provide a brief description of the requirements from
the Google Objective-C style guide. The more descriptive diagnostics may
help clarify that functions in the global namespace must have an
appropriate prefix followed by Pascal case (engineers working previously
with static functions might not immediately understand the different
requirements of static and non-static functions).

Test Notes:
Verified against the clang-tidy tests.

Reviewers: benhamilton, aaron.ballman

Reviewed By: benhamilton

Subscribers: MyDeveloperDay, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D55482

llvm-svn: 349123
2018-12-14 03:13:31 +00:00
Douglas Yung 29bfeb97d4 Revert "[clang-tidy] Share the forced linking code between clang-tidy tool and plugin"
This reverts commit r349038 as it was causing test failures:

http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/22185
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/40886

llvm-svn: 349121
2018-12-14 02:04:04 +00:00
Hyrum Wright 35cb7e9fe8 [clang-tidy] Add the abseil-duration-subtraction check
Summary:
This check uses the context of a subtraction expression as well as knowledge
about the Abseil Time types, to infer the type of the second operand of some
subtraction expressions in Duration conversions. For example:

   absl::ToDoubleSeconds(duration) - foo

can become
   absl::ToDoubleSeconds(duration - absl::Seconds(foo))

This ensures that time calculations are done in the proper domain, and also
makes it easier to further deduce the types of the second operands to these
expressions.

Reviewed By: JonasToth

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D55245

llvm-svn: 349073
2018-12-13 19:23:52 +00:00
Ivan Donchevskii e74d487be8 [clang-tidy] Share the forced linking code between clang-tidy tool and plugin
Extract code that forces linking to the separate header and include it in both plugin and standalone tool

Differential Revision: https://reviews.llvm.org/D55595

llvm-svn: 349038
2018-12-13 14:37:17 +00:00
Fangrui Song 41c249adc4 Add explicit dependency on clangSerialization after rC348911
llvm-svn: 348916
2018-12-12 08:25:16 +00:00
Jonas Toth 4b59a1fe29 Use the standard Duration factory matcher
Summary: A new check came in over the weekend; it should use our existing infrastructure for matching `absl::Duration` factories.

Patch by hwright.

Reviewers: JonasToth

Reviewed By: JonasToth

Subscribers: astrelni

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D55541

llvm-svn: 348842
2018-12-11 12:45:51 +00:00
Jonas Toth e740145e19 [clang-tidy] insert release notes for new checkers alphabetically
Summary:
Almost all code review comments on new checkers {D55433} {D48866} {D54349} seem to ask for the release notes to be added alphabetically, plus I've seen commits by @Eugene.Zelenko reordering the lists

Make add_new_check.py add those release notes alphabetically based on checker name

If include-fixer section is seen add it at the end

Minor change in the message format to prevent double newlines added before the checker.

Do the tools themselves have unit tests? (sorry new to this game)

- Tested adding new checker at the beginning
- Tested on adding new checker in the middle
- Tested on empty ReleasesNotes.rst (as we would see after RC)

Patch by MyDeveloperDay.

Reviewers: alexfh, JonasToth, curdeius, aaron.ballman, benhamilton, hokein

Reviewed By: JonasToth

Subscribers: cfe-commits, xazax.hun, Eugene.Zelenko

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D55508

llvm-svn: 348793
2018-12-10 19:41:53 +00:00
Eric Fiselier 2bbbd8be24 [clang-tidy]: Abseil: new check 'abseil-upgrade-duration-conversions'
Patch by Alex Strelnikov.
Reviewed as D53830

Introduce a new check to upgrade user code based on upcoming API breaking changes to absl::Duration.

The check finds calls to arithmetic operators and factory functions for absl::Duration that rely on
an implicit user defined conversion to int64_t. These cases will no longer compile after proposed
changes are released. Suggested fixes explicitly cast the argument int64_t.

llvm-svn: 348633
2018-12-07 20:03:03 +00:00
Haojian Wu 75f6caddab [clang-tidy] Remove duplicated getText implementation, NFC
llvm-svn: 348583
2018-12-07 11:25:37 +00:00
Jonas Toth 71a29aa947 Revert "[clang-tidy] new check: bugprone-branch-clone"
The patch broke on buildbot with assertion-failure. Revert until this
is figured out.

llvm-svn: 348344
2018-12-05 09:34:18 +00:00
Jonas Toth cd207f1552 [clang-tidy] new check: bugprone-branch-clone
Summary:
Implement a check for detecting if/else if/else chains where two or more
branches are Type I clones of each other (that is, they contain identical code)
and for detecting switch statements where two or more consecutive branches are
Type I clones of each other.

Patch by donat.nagy.

Reviewers: alexfh, hokein, aaron.ballman, JonasToth

Reviewed By: JonasToth

Subscribers: MTC, lebedev.ri, whisperity, xazax.hun, Eugene.Zelenko, mgorny, rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D54757

llvm-svn: 348343
2018-12-05 09:16:25 +00:00
Jonas Toth c361e0d627 Fix a false positive in misplaced-widening-cast
Summary:
bugprone-misplaced-widening-cast check
used to give a false warning to the
following example.

 enum DaysEnum{
    MON = 0,
    TUE = 1
    };

 day = (DaysEnum)(day + 1);
 //warning: either cast from 'int' to 'DaysEnum' is ineffective...

But i think int to enum cast is not widening neither ineffective.

Patch by dkrupp.

Reviewers: JonasToth, alexfh

Reviewed By: alexfh

Subscribers: rnkovacs, Szelethus, gamesh411, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D55255

llvm-svn: 348341
2018-12-05 08:29:56 +00:00
Stephane Moore af4755aca8 [clang-tidy/checks] Update objc-property-declaration check to allow arbitrary acronyms and initialisms 🔧
Summary:
§1 Description

This changes the objc-property-declaration check to allow arbitrary acronyms and initialisms instead of using whitelisted acronyms. In Objective-C it is relatively common to use project prefixes in property names for the purposes of disambiguation. For example, the CIColor¹ and CGColor² properties on UIColor both represent symbol prefixes being used in proeprty names outside of Apple's accepted acronyms³. The union of Apple's accepted acronyms and all symbol prefixes that might be used for disambiguation in property declarations effectively allows for any arbitrary sequence of capital alphanumeric characters to be acceptable in property declarations. This change updates the check accordingly.

The test variants with custom configurations are deleted as part of this change because their configurations no longer impact behavior. The acronym configurations are currently preserved for backwards compatibility of check configuration.

[1] https://developer.apple.com/documentation/uikit/uicolor/1621951-cicolor?language=objc
[2] https://developer.apple.com/documentation/uikit/uicolor/1621954-cgcolor?language=objc
[3] https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CodingGuidelines/Articles/APIAbbreviations.html#//apple_ref/doc/uid/20001285-BCIHCGAE

§2 Test Notes

Changes verified by:
• Running clang-tidy unit tests.
• Used check_clang_tidy.py to verify expected output of processing objc-property-declaration.m

Reviewers: benhamilton, Wizard

Reviewed By: benhamilton

Subscribers: jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D51832

llvm-svn: 348331
2018-12-05 03:44:03 +00:00
Stephane Moore f6d96e0f98 [clang-tidy] Ignore namespaced and C++ member functions in google-objc-function-naming check 🙈
Summary: The google-objc-function-naming check applies to functions that are not namespaced and should not be applied to C++ member functions. Such function declarations should be ignored by the check to avoid false positives in Objective-C++ sources.

Reviewers: benhamilton, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D55101

llvm-svn: 348317
2018-12-04 23:40:42 +00:00
Jonas Toth 3f51ee19ae [clang-tidy] Fix unordered_map failure with specializing std::hash<> and remove previous wrong attempt at doing so
llvm-svn: 348172
2018-12-03 19:41:04 +00:00
Jonas Toth 00f1d76738 [clang-tidy] Recommit: Add the abseil-duration-comparison check
Summary:
This check finds instances where Duration values are being converted to a numeric value in a comparison expression, and suggests that the conversion happen on the other side of the expression to a Duration.  See documentation for examples.

This also shuffles some code around so that the new check may perform in sone step simplifications also caught by other checks.
Compilation is unbroken, because the hash-function is now directly
specified for std::unordered_map, as 'enum class' does not compile as
key (seamingly only on some compilers).

Patch by hwright.

Reviewers: aaron.ballman, JonasToth, alexfh, hokein

Reviewed By: JonasToth

Subscribers: sammccall, Eugene.Zelenko, xazax.hun, cfe-commits, mgorny

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D54737

llvm-svn: 348169
2018-12-03 19:22:08 +00:00
Jonas Toth b77711e297 Revert "[clang-tidy] Add the abseil-duration-comparison check"
This commit broke buildbots and needs adjustments.

llvm-svn: 348165
2018-12-03 18:59:27 +00:00
Jonas Toth 5da1825ebc [clang-tidy] Add the abseil-duration-comparison check
Summary:
This check finds instances where Duration values are being converted to a numeric value in a comparison expression, and suggests that the conversion happen on the other side of the expression to a Duration.  See documentation for examples.

This also shuffles some code around so that the new check may perform in sone step simplifications also caught by other checks.

Patch by hwright.

Reviewers: aaron.ballman, JonasToth, alexfh, hokein

Reviewed By: JonasToth

Subscribers: sammccall, Eugene.Zelenko, xazax.hun, cfe-commits, mgorny

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D54737

llvm-svn: 348161
2018-12-03 18:35:56 +00:00
Aaron Ballman e0fddb4e56 Fix false positive with lambda assignments in cert-err58-cpp.
This check is about preventing exceptions from being thrown before main() executes, and assigning a lambda (rather than calling it) to a global object cannot throw any exceptions.

llvm-svn: 347761
2018-11-28 15:04:38 +00:00
Hans Wennborg cab8dd692e Re-commit r347419 "Update call to EvaluateAsInt() to the new syntax."
llvm-svn: 347757
2018-11-28 14:04:26 +00:00
Aaron Ballman dda6290f16 Fix a false-positive with cert-err58-cpp.
If a variable is declared constexpr then its initializer needs to be a constant expression, and thus, cannot throw. This check is about not throwing exceptions before main() runs, and so it doesn't apply if the initializer cannot throw. This silences the diagnostic when initializing a constexpr variable and fixes PR35457.

llvm-svn: 347745
2018-11-28 11:57:13 +00:00
Malcolm Parsons d8851b5def [clang-tidy] Ignore bool -> single bit bitfield conversion in readability-implicit-bool-conversion
Summary: There is no ambiguity / information loss in this conversion

Reviewers: alexfh, aaron.ballman, hokein

Reviewed By: alexfh

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54941

llvm-svn: 347671
2018-11-27 16:23:39 +00:00
Hans Wennborg 02f5511ff4 Revert r347419 "Update call to EvaluateAsInt() to the new syntax."
It's pre-requisite was reverted in r347656.

llvm-svn: 347657
2018-11-27 14:15:37 +00:00
Alexander Kornienko 8577dcc533 [clang-tidy] Avoid inconsistent notes in readability-container-size-empty
When a warning is issued in a template instantiation, the check would previously
use template arguments in a note, which would result in inconsistent or
duplicate warnings (depending on how deduplication was done). This patch removes
template arguments from the note.

llvm-svn: 347652
2018-11-27 10:53:44 +00:00
Guillaume Chatelet 10a7ee7044 [clang-tidy] Improving narrowing conversions
Summary:
Newly flagged narrowing conversions:
 - integer to narrower signed integer (this is compiler implementation defined),
 - integer - floating point narrowing conversions,
 - floating point - integer narrowing conversions,
 - constants with narrowing conversions (even in ternary operator).

Reviewers: hokein, alexfh, aaron.ballman, JonasToth

Reviewed By: aaron.ballman, JonasToth

Subscribers: lebedev.ri, courbet, nemanjai, xazax.hun, kbarton, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D53488

llvm-svn: 347570
2018-11-26 16:25:55 +00:00
Haojian Wu 77c56fffad [clang-tidy] No warning for auto new expression in smart check
Summary: The fix for `auto` new expression is illegal.

Reviewers: aaron.ballman

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54832

llvm-svn: 347551
2018-11-26 12:42:08 +00:00
Alexander Kornienko f90bdf73a2 [clang-tidy] PrintStackTraceOnErrorSignal
llvm-svn: 347546
2018-11-26 11:11:52 +00:00
Haojian Wu dbfa9c3e0a [clang-tidy] Don't generate incorrect fixes for class with deleted copy constructor in smart_ptr check.
Summary:
The fix for aggregate initialization (`std::make_unique<Foo>(Foo {1, 2})` needs
to see Foo copy constructor, otherwise we will have a compiler error. So we
only emit the check warning.

Reviewers: JonasToth, aaron.ballman

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54745

llvm-svn: 347537
2018-11-26 09:33:08 +00:00
Alexander Kornienko 976e0c07a0 A bit of AST matcher cleanup, NFC.
Removed the uses of the allOf() matcher inside node matchers that are implicit
allOf(). Replaced uses of allOf() with the explicit node matcher where it makes
matchers more readable. Replace anyOf(hasName(), hasName(), ...) with the more
efficient and readable hasAnyName().

llvm-svn: 347520
2018-11-25 02:41:01 +00:00
Alexander Kornienko daa515e6a1 [clang-tidy] Ignore matches in template instantiations (cert-dcl21-cpp)
The test fails with a local modification to
clang-tidy/ClangTidyDiagnosticConsumer.cpp to include fixes into the key when
deduplicating the warnings.

llvm-svn: 347495
2018-11-23 14:30:14 +00:00
Alexander Kornienko b34b6ffa9d [clang-tidy] Ignore template instantiations in modernize-use-using
The test I'm adding passes without the change due to the deduplication logic in
ClangTidyDiagnosticConsumer::take(). However this bug manifests in our internal
integration with clang-tidy.
I've verified the fix by locally changing LessClangTidyError to consider
replacements.

llvm-svn: 347470
2018-11-22 16:10:18 +00:00
Bill Wendling d0b6706c97 Update call to EvaluateAsInt() to the new syntax.
llvm-svn: 347419
2018-11-21 20:45:00 +00:00
Nico Weber 63992b02d0 Revert 347366, its prerequisite 347364 got reverted.
llvm-svn: 347390
2018-11-21 12:49:22 +00:00
Bill Wendling 194c64ef4f Update EvaluateAsInt to the new syntax.
llvm-svn: 347366
2018-11-20 23:24:39 +00:00
Haojian Wu c63d935b23 [clang-tidy] Don't generate incorrect fixes for class constructed from list-initialized arguments
Summary:
Currently the smart_ptr check (modernize-make-unique) generates the
fixes that cannot compile for cases like below -- because brace list can
not be deduced in `make_unique`.

```
struct Bar { int a, b; };
struct Foo { Foo(Bar); };
auto foo = std::unique_ptr<Foo>(new Foo({1, 2}));
```

Reviewers: aaron.ballman

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54704

llvm-svn: 347315
2018-11-20 15:45:15 +00:00
Aaron Ballman 639c87ef53 Add the abseil-duration-factory-scale check.
This check removes unneeded scaling of arguments when calling Abseil Time factory functions.

Patch by Hyrum Wright.

llvm-svn: 347163
2018-11-18 16:41:06 +00:00
Stephane Moore e34a761d5b [clang-tidy/checks] Implement a clang-tidy check to verify Google Objective-C function naming conventions 📜
Summary:
§1 Description

This check finds function names in function declarations in Objective-C files that do not follow the naming pattern described in the Google Objective-C Style Guide. Function names should be in UpperCamelCase and functions that are not of static storage class should have an appropriate prefix as described in the Google Objective-C Style Guide. The function `main` is a notable exception. Function declarations in expansions in system headers are ignored.

Example conforming function definitions:
```
static bool IsPositive(int i) { return i > 0; }
static bool ABIsPositive(int i) { return i > 0; }
bool ABIsNegative(int i) { return i < 0; }
```

A fixit hint is generated for functions of static storage class but otherwise the check does not generate a fixit hint because an appropriate prefix for the function cannot be determined.

§2 Test Notes
* Verified clang-tidy tests pass successfully.
* Used check_clang_tidy.py to verify expected output of processing google-objc-function-naming.m

Reviewers: benhamilton, hokein, Wizard, aaron.ballman

Reviewed By: benhamilton

Subscribers: Eugene.Zelenko, mgorny, xazax.hun, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D51575

llvm-svn: 347132
2018-11-17 02:37:21 +00:00
Stephane Moore 20cd5f2e20 [clang-tidy] Fix reference to -[NSError init] in AvoidNSErrorInitCheck.h
llvm-svn: 347000
2018-11-15 22:38:39 +00:00
Sam McCall 35f3da1925 [clang-tidy] Update checks to play nicely with limited traversal scope added in r346847
Summary: (See D54204 for original review)

Reviewers: hokein

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54579

llvm-svn: 346961
2018-11-15 15:06:11 +00:00
Roman Lebedev 2634bd5995 [clang-tidy] Avoid C arrays check
Summary:
[[ https://bugs.llvm.org/show_bug.cgi?id=39224 | PR39224 ]]
As discussed, we can't always do the transform automatically due to that array-to-pointer decay of C array.
In order to detect whether we can do said transform, we'd need to be able to see all usages of said array,
which is, i would say, rather impossible if e.g. it is in the header.
Thus right now no fixit exists.

Exceptions: `extern "C"` code.

References:
* [[ https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es27-use-stdarray-or-stack_array-for-arrays-on-the-stack | CPPCG ES.27: Use std::array or stack_array for arrays on the stack ]]
* [[ https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#slcon1-prefer-using-stl-array-or-vector-instead-of-a-c-array | CPPCG SL.con.1: Prefer using STL array or vector instead of a C array ]]
* HICPP `4.1.1 Ensure that a function argument does not undergo an array-to-pointer conversion`
* MISRA `5-2-12 An identifier with array type passed as a function argument shall not decay to a pointer`

Reviewers: aaron.ballman, JonasToth, alexfh, hokein, xazax.hun

Reviewed By: JonasToth

Subscribers: Eugene.Zelenko, mgorny, rnkovacs, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D53771

llvm-svn: 346835
2018-11-14 09:01:08 +00:00
Jonas Toth 6b3d33e996 [clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.

For example:

```
int main() {
  long size = 300000;
  for( short int i = 0; i < size; ++i) {}
}
```

The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.

The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.

Patch by ztamas.

Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity

Reviewed By: JonasToth, whisperity

Differential Revision: https://reviews.llvm.org/D53974

llvm-svn: 346665
2018-11-12 16:01:39 +00:00
Jonas Toth ef67ce0f6f [clang-tidy] fix PR39583 - ignoring ParenCast for string-literals in pro-bounds-array-to-pointer-decay
Summary:
The fix to the issue that `const char* p = ("foo")` is diagnosed as decay
is to ignored the ParenCast.
Resolves PR39583

Reviewers: aaron.ballman, alexfh, hokein

Reviewed By: aaron.ballman

Subscribers: nemanjai, xazax.hun, kbarton, cfe-commits

Differential Revision: https://reviews.llvm.org/D54281

llvm-svn: 346555
2018-11-09 20:57:28 +00:00
Bill Wendling ec54d6121c Ignore implicit things like ConstantExpr.
llvm-svn: 346461
2018-11-09 01:32:30 +00:00
Sam McCall 3c1f4903b7 [clang-tidy] Untangle layering in ClangTidyDiagnosticConsumer somewhat. NFC
Summary:
Clang's hierarchy is CompilerInstance -> DiagnosticsEngine -> DiagnosticConsumer.
(Ownership is optional/shared, but this structure is fairly clear).

Currently ClangTidyDiagnosticConsumer *owns* the DiagnosticsEngine:
 - this inverts the hierarchy, which is confusing
 - this means ClangTidyDiagnosticConsumer() mutates the passed-in context, which
   is both surprising and limits flexibility
 - it's not possible to use a different DiagnosticsEngine with ClangTidy

This means a little bit more code in the places ClangTidy is used standalone,
but more flexibility in using ClangTidy with other diagnostics configurations.

Reviewers: hokein

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54033

llvm-svn: 346418
2018-11-08 17:42:16 +00:00
Sam McCall 80a3c561a7 [clang-tidy] run() doesn't update the SourceManager.
Summary:
By now the context's SourceManager is now initialized everywhere that
ClangTidyCheck::registerMatcher() is called, so the call from run() seems
entirely redundant, and indeed all the tests pass.

This solves a problem with embedding clang-tidy: if using a DiagnosticsEngine
which already has file state, re-setting its SourceManager (to the same value)
causes an assertion.
(There are other ways to solve this problem, but this is the simplest).

Reviewers: hokein, alexfh

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D54061

llvm-svn: 346219
2018-11-06 09:28:23 +00:00
Alexander Kornienko 3444cb9993 [clang-tidy] Fixed code sample in a comment. NFC
llvm-svn: 345984
2018-11-02 15:29:37 +00:00
Alexander Kornienko 8f810c3cdc [clang-tidy] .reset(new X) -> make_unique<X>() in a comment. NFC
llvm-svn: 345979
2018-11-02 15:03:43 +00:00
Tim Northover 314fbfa1c4 Reapply Logging: make os_log buffer size an integer constant expression.
The size of an os_log buffer is known at any stage of compilation, so making it
a constant expression means that the common idiom of declaring a buffer for it
won't result in a VLA. That allows the compiler to skip saving and restoring
the stack pointer around such buffers.

This also moves the OSLog and other FormatString helpers from
libclangAnalysis to libclangAST to avoid a circular dependency.

llvm-svn: 345971
2018-11-02 13:14:11 +00:00