fatal error for now

Appeases build bots while being investigated.

Take care of a TODO. This
check makes sure that the fexcept_t
value fits in an int value.

TODO introduced in:
https://github.com/llvm/llvm-project/commit/9550f8ba9a3a697f28a7920c8aeb5cba1e8003a6

The HOST_LINK_VERSION is a hardcoded string in Darwin clang that detects
the linker version at configure time. The driver uses this information
to build the correct set of arguments for the linker. This patch detects
the linker version again during compiler-rt configuration and passes it
to the libfuzzer tests. This allows a clang built on a machine with a
new linker to run compiler-rt tests on a machine with an old linker.

rdar://125932376

Building the Apple way turns off plugin support, meaning we don't need
to export unloadable symbols from all executables. While deadstripping
effects aren't expected to change, enabling this across all tools
prevents the creation of export tries. This saves us ~3.5 MB in just the
universal build of `clang`.

These are new in clang-19+, gcc-14+.

Added unit tests for all of the linux report error functions.

* Capture reexported libraries, allowable clients, rpaths, shared cache
eligibility.
* Add support for select Xarch options.
* Add diagnostics related to capturing these options.
* Add support for verifying these attributes against what is encoded in
the dylib.

Closes #87564

In section 3.4.2, some example of illegal data transfer using expression
are given. One of it is when multiple device objects are part of an
expression in the rhs. Current implementation allow a single device
object in such case. This patch adds a similar restriction.

Until we can reliably check the legality and improve our selection of these,
don't form them at all.

These tests consist of patterns like (sh3add Z, (add X, (slli Y, 6)))
that can be reassociated to form (sh3add (sh3add Y, Z), X).

Previously we only checked for C.

sed was being used to use the same test functions with eq/ne branch
condition.

This commit duplicates the test functions so that we have a version
with each condition. This allows us to remove 2 RUN lines.

I plan to add a Zca testing to this file which now requires 1 new
RUN line instead of 2.

Followup to issues addressed here: #87397

Fixes https://github.com/llvm/llvm-project/issues/85767.

The aggregate deduction guides are handled in a separate code path. We
don't generate dedicated aggregate deduction guides for alias templates
(we just reuse the ones from the underlying template decl by accident).
The patch fixes this incorrect issue.

Note: there is a small refactoring change in this PR, where we move the
cache logic from `Sema::DeduceTemplateSpecializationFromInitializer` to
`Sema::DeclareImplicitDeductionGuideFromInitList`

While attempting to build some Rust code, I was getting linker errors
due to missing functions that are implemented in `compiler-rt`. Turns
out that when `compiler-rt` is built for Arm64EC, all its function names
are mangled with the leading `#`.

This change removes the hard-coded list of library-implemented
intrinsics to mangle for Arm64EC, and instead assumes that they all must
be mangled.

Implements: https://wg21.link/P2872R3

Test description says constant does not fit in 12 bits, but the constant
used was -2048 which does fit in 12 bits. Update to -2049.

Also remove uses of -NOT in favor of positive checks. One of the -NOT
should have been using RESBROPT instead of "c.beqz" so that it would
check for the absense of the correct instruction based on the sed
replacement on the RUN line.

Use symbol `.data` (STT_SECTION) instead of `__ehdr_start` for some
relocation entries. See discussion in

[72714/#discussion_r1517127619](https://github.com/llvm/llvm-project/pull/72714/#discussion_r1517127619)

This change implements the HLSL floating literal suffixes for half and
double literals. The PR for the HLSL language specification for this
behavior is https://github.com/microsoft/hlsl-specs/pull/175.

The TL;DR is that the `h` suffix on floating literals means `half`, and
the `l` suffix means `double`.

The expected behavior and diagnostics are different if native half is
supported. When native half is not enabled half is 32-bit so implicit
conversions to float do not lose precision and do not warn.

In all cases `half` and `float` are distinct types.

Resolves #85712

The commit f11b056c (#76304) breaks `clang` and other tools if they are
used from a RAMDrive. `GetFinalPathNameByHandleW()` may return 0 and
GetLastError 0x28. This patch fixes that issue. Note `real_path()` uses
`openFileForRead()` but it reports the error only if failed to open a
file. Getting `RealPath` is optional functionality.

BTW, `sys::fs::real_path()` resolves not only symlinks, but also network
drives and virtual drives created by the `subst` tool. It may break an
automation. It is better to detect symlinks and resolve only symlinks.

https://alive2.llvm.org/ce/z/ivPZ26 for the abs transformations.

Reviewers: RKSimon

Reviewed By: RKSimon

Pull Request: https://github.com/llvm/llvm-project/pull/86135

We have two identical "DeduceTemplateArguments" implementations for
class and variable partial template specializations, this patch removes
the duplicated code.

This was the paper that added Universal Character Names to C.

to support certain static relocations in the REL format. See #87328 for
the armasm need.

Note: `R_AARCH64_{ABS64,PREL32,PREL64}` have been implemented by https://reviews.llvm.org/D120535

Pull Request: https://github.com/llvm/llvm-project/pull/87733

These are not necessary when not performing codegen.

[clang][modules] Headers meant to be included multiple times can be completely invisible in clang module builds (#83660)

Once a file has been `#import`'ed, it gets stamped as if it was `#pragma
once` and will not be re-entered, even on #include. This means that any
errant #import of a file designed to be included multiple times, such as
<assert.h>, will incorrectly mark it as include-once and break the
multiple include functionality. Normally this isn't a big problem, e.g.
<assert.h> can't have its NDEBUG mode changed after the first #import,
but it is still mostly functional. However, when clang modules are
involved, this can cause the header to be hidden entirely.

Objective-C code most often uses #import for everything, because it's
required for most Objective-C headers to prevent double inclusion and
redeclaration errors. (It's rare for Objective-C headers to use macro
guards or `#pragma once`.) The problem arises when a submodule includes
a multiple-include header. The "already included" state is global across
all modules (which is necessary so that non-modular headers don't get
compiled into multiple translation units and cause redeclaration
errors). If another module or the main file #import's the same header,
it becomes invisible from then on. If the original submodule is not
imported, the include of the header will effectively do nothing and the
header will be invisible. The only way to actually get the header's
declarations is to somehow figure out which submodule consumed the
header, and import that instead. That's basically impossible since it
depends on exactly which modules were built in which order.

#import is a poor indicator of whether a header is actually
include-once, as the #import is external to the header it applies to,
and requires that all inclusions correctly and consistently use #import
vs #include. When modules are enabled, consider a header marked
`textual` in its module as a stronger indicator of multiple-include than
#import's indication of include-once. This will allow headers like
<assert.h> to always be included when modules are enabled, even if
#import is erroneously used somewhere.

As a first step in adding clause support for OpenACC to Semantic
Analysis, this patch adds the 'base' AST nodes required for clauses.

This patch has no functional effect at the moment, but followup patches
will add the semantic analysis of clauses (plus individual clauses).

Add missing closing parenthesis and re-flow the snippet to what clang
format would generate.

It's useful to have some significant build options visible in the
version when investigating problems with a specific compiler artifact.
This makes it easy to see if assertions, expensive checks, sanitizers,
etc. are enabled when checking a compiler version.

Example config line output:
Build configuration: +unoptimized, +assertions, +asan, +ubsan

When there is `>>` in source from the right brackets of a nested
template, the end location of the inner template points into a scratch
space with a single `>` token. This prevents the lexer from seeing the
`>>` token in the original source.

However, this causes the range to appear to be partially in a macro, and
is problematic if we are trying to avoid ranges with any macro
expansions.

This change detects these split tokens in token ranges, converting it to the
corresponding character range without the expansion.

The previous URL was stale, and referenced 'master' instead of 'main',
which will never be updated.

Reviewers: topperc, enh-google

Reviewed By: enh-google

Pull Request: https://github.com/llvm/llvm-project/pull/87726