The current handling of the operators ||, && and ?: has a number of false
positive and false negative. The issues for operator || and && are:

1. We need to add sequencing regions for the LHS and RHS as is done for the
   comma operator. Not doing so causes false positives in expressions like
   `((a++, false) || (a++, false))` (from PR39779, see PR22197 for another
    example).

2. In the current implementation when the evaluation of the LHS fails, the RHS
   is added to a worklist to be processed later. This results in false negatives
   in expressions like `(a && a++) + a`.

Fix these issues by introducing sequencing regions for the LHS and RHS, and by
not deferring the visitation of the RHS.

The issues with the ternary operator ?: are similar, with the added twist that
we should not warn on expressions like `(x ? y += 1 : y += 2)` since exactly
one of the 2nd and 3rd expression is going to be evaluated, but we should still
warn on expressions like `(x ? y += 1 : y += 2) = y`.

Differential Revision: https://reviews.llvm.org/D57747

Reviewed By: rsmith

NFCs factored out of the following patches:
- Change all of the `Expr *` to `const Expr *` in SequenceChecker for
  const-correctness. SequenceChecker should not modify AST nodes.
- Add some comments.
- clang-format

Differential Revision: https://reviews.llvm.org/D57659

Reviewed By: xbolva00

Added support for constraint satisfaction checking and partial ordering of constraints in constrained partial specialization and function template overloads.
Re-commit after fixing some crashes and warnings.

Differential Revision: https://reviews.llvm.org/D41910

Previously, SWIG was only a hard dependency if python bindings were
enabled.

Since bf03e17c, scripts/CMakeLists.txt
is included unconditionally, while that file adds the hard dependency
on SWIG.

Instead, only include that file if either python or lua bindings are
enabled.

gcc/config/{i386,s390} support -mnop-mcount. We currently only support
-mnop-mcount for SystemZ. The function attribute "mnop-mcount" is
ignored on other targets.

gcc/config/{i386,s390} support -mfentry. We currently only support
-mfentry for X86 and SystemZ. TargetOpcode::FENTRY_CALL is not handled
on other targets.

  % clang -target aarch64 -pg -mfentry a.c -c
  fatal error: error in backend: Not supported instr: <MCInst 21>

-mfentry, -mrecord-mcount, and -mnop-mcount were invented for Linux
ftrace. Linux uses $(call cc-option-yn,-mrecord-mcount) to detect if the
specific feature is available. Reject unsupported features so that Linux
build system will not wrongly consider them available and cause
build/runtime failures.

Note, GCC has stricter checks that we do not implement, e.g. -fpic/-fpie
-fnop-mcount is not allowed on x86, -fpic/-fpie -mfentry is not allowed
on x86-32.

GCC's x86 and s390 ports support -mrecord-mcount. Other ports reject the
option.

  aarch64-linux-gnu-gcc: error: unrecognized command line option ‘-mrecord-mcount’

Allowing this option can cause failures when building Linux kernel for
aarch64, powerpc64, etc, which will think the feature is available if
the clang command returns 0.

Fix the nonsensical error messages for when breakpoint and watchpoint
callbacks are not supported.

This ensures that watchpoint command honors the scripting language
passed with `-s`. Currently the argument ignores the actual language and
only uses it to differentiate between lldb and script commands.

 - Fix enum entry order.
 - Fix missing enum case in CommandObjectBreakpointCommand.
 - Add Lua entry to swtich in LanguageToString and simplify the code.

When a function is used as a breakpoint command, use to the debugger's
default scripting language, unless a language is explicitly specified.

This now defines HAVE_VCS_VERSION_INC for all files in Basic,
but now the BUILD.gn file has only a single "sources" field again,
and the automerger requires that. Having the automerger work for
clang/lib/Basic is a very nice to have, and the downside seems tiny.

getLastArgIntValue is a useful utility function to get command line argument as an integer.
Currently it is in Frontend so that it can only be used by clang -cc1. Move it to basic so
that it can also be used by clang driver.

Differential Revision: https://reviews.llvm.org/D71080

This ensures that breakpoint command honors the scripting language
passed with `-s`. Currently the argument ignores the actual language and
only uses it to differentiate between lldb and script commands.

Fixes a bogus enum value for the scripting language options, adds an
entry for Lua and refactored the code to use an exhaustive switch.

Rather than holding on to one script interpreter, it should be possible
to request a script interpreter for a specific scripting language. The
GetScriptInterpreter method now takes an optional scripting language
argument.

(NFC)

Don't create a new lua state on every operation. Share a single state
across the lifetime of the script interpreter. Add simple locking to
prevent two threads from modifying the state concurrently.

ClangASTContext::getASTContext() currently returns a ptr but we have an assert there since a
while that the ASTContext is not a nullptr. This causes that we still have a lot of code
that is doing nullptr checks on the result of getASTContext() which is all unreachable code.

This patch changes the return value to a reference to make it clear this can't be a nullptr
and deletes all the nullptr checks.

This patch uses SWIG to generate the Lua bindings for the SB API. It
covers most of the API, but some methods require a type map similar to
Python.

Discussion on the mailing list:
http://lists.llvm.org/pipermail/lldb-dev/2019-December/015812.html

Differential revision: https://reviews.llvm.org/D71235

Makes sure that the script works fine both in python2 and python3.

Patch by Pavel Samolysov!

Differential Revision: https://reviews.llvm.org/D71746

Summary:
If none of the input files are ELF object files (for example, when
generating an object file from a single binary input file via
"-b binary"), use a fallback value for the ELF header flags instead
of crashing with an assertion failure.

Reviewers: MaskRay, ruiu, espindola

Reviewed By: MaskRay, ruiu

Subscribers: kevans, grimar, emaste, arichardson, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits, jrtc27

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71101

We missed a constraint in D44833
when folding a bitcast into a GEP with vector/array types.
If the alloc sizes specified by the datalayout don't match,
this could miscompile as shown in:
https://bugs.llvm.org/show_bug.cgi?id=44321

Differential Revision: https://reviews.llvm.org/D71771

As discussed in PR44330:
https://bugs.llvm.org/show_bug.cgi?id=44330
...the transform from pow(X, -0.5) libcall/intrinsic to
reciprocal square root can result in small deviations from
the expected result due to differences in the pow()
implementation and/or the extra rounding step from the division.

This patch proposes to allow that difference with either the
'approximate functions' or 'reassociate' FMF:
http://llvm.org/docs/LangRef.html#fast-math-flags

In practice, this likely means that the code is compiled with
all of 'fast' (-ffast-math), but I have preserved the existing
specializations for -0.0/-INF that enable generating safe code
if those special values are allowed simultaneously with
allowing approximation/reassociation.

The question about whether a similar restriction is needed for
the non-reciprocal case -- pow(X, 0.5) -- is deferred. That
transform is allowed without FMF currently, and this patch does
not change that behavior.

Differential Revision: https://reviews.llvm.org/D71706

Their naming is misleading as they only return the
ClangASTContext-owned variables. For ClangASTContext instances constructed
for a given clang::ASTContext they silently generated duplicated instances
(e.g., a second IdentifierTable) that were essentially unusable.

This removes all these getters as they are anyway not very useful in comparison
to just calling the clang::ASTContext getters. The initialization
code has been moved to the CreateASTContext initialization method so that all
code for making our own clang::ASTContext is in one place.

We cannot pick reserved registers as rename registers.

Fixes https://bugs.llvm.org/show_bug.cgi?id=44358

This avoids unneeded copies when using a range-based for loops.

This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.

Differential Revision: https://reviews.llvm.org/D70869

Differential revision: https://reviews.llvm.org/D69223

I'm unable to get this test working there.

After d567b0ba, the test suite no longer
passes if hexagon is disabled.

It does not seem to run automatically on windows.

Reviewers: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71680