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Without --sample-period, no assumptions are made about perf profile sample frequencies. This is useful for comparing relative hotness of different program locations within the same profile.

With --sample-period, LBR- and IP-based profile hit counts are adjusted to estimate the absolute total event count for each program location. This makes it reasonable to compare hit counts between different profiles, e.g., between LBR-based execution frequency profiles and IP-based branch mispredict profiles.

klausler and others added 30 commits July 18, 2024 16:32
When a DEC legacy STRUCTURE definition appears within another, its
STRUCTURE statement must also declare some components of the enclosing
structure.

Fixes llvm#99288.
- Add implementation for x86_64 and linux
- Add test

The output is like

==XXYYZZ==Register values:
rax = 0x...  rbx = 0x...  rcx = 0x...  rdx = 0x...
rdi = 0x...  rsi = 0x...  rbp = 0x...  rsp = 0x...
 r8 = 0x...   r9 = 0x...  r10 = 0x...  r11 = 0x...
r12 = 0x...  r13 = 0x...  r14 = 0x...  r15 = 0x...
goo.gl is going away: https://developers.googleblog.com/en/google-url-shortener-links-will-no-longer-be-available/

Fix goo.gl link from:
- http://goo.gl/QKbem
+ https://static.usenix.org/event/usenix05/tech/general/full_papers/seward/seward_html/usenix2005.html
and reflow the comment a bit to make it look a bit better after the URL change,
although it's not perfect now.

Committed as obvious.

Bug: llvm#99586
…e() overload (llvm#98403)

This PR adds `SBSaveCoreOptions`, which is a container class for options
when LLDB is taking coredumps. For this first iteration this container
just keeps parity with the extant API of `file, style, plugin`. In the
future this options object can be extended to allow users to take a
subset of their core dumps.
Previously these targets were disabled, but with a relatively new
rules_python we can build these pointing at a hermetic python, which
allows us to build these safely. Users can still access the files
directly if they need to customize how these are built.
This patch adds a couple of unit tests:

- SetSubtractSmallPtrSet exercises the code path involving remove_if,
  added in d772cdd.  Note that
  SmallPtrSet supports remove_if.

- SetSubtractSmallVector exercises the code path involving
  S1.erase(*SI) and ensures that set_subtract continues to accept S2
  being a vector, which does not have contains.
Pointers print more leading zeroes for better alignment.
This patch fixes:

  compiler-rt/lib/sanitizer_common/sanitizer_tls_get_addr.cpp:126:72:
  error: format specifies type 'void *' but the argument has type
  'uptr *' (aka 'unsigned long *') [-Werror,-Wformat-pedantic]
1. Move checks into parent test/CMakeLists.txt
2. COMPILER_RT_INCLUDE_TESTS disable both lit and
   gtests. Before it was very inconsistent between
   sanitizers.
This implements tracking of moving instrs with `moveBefore()`.
The current git_repository usage points to tags, which leads to warnings
that the build may not be reproducable due to not using a git sha.

The docs for
[git_repository](https://bazel.build/rules/lib/repo/git#git_repository)
recommend using `http_archive`, so switch to that instead. Also bump to
newer versions for these two repos.
…96025)

Base on the discussion
https://discourse.llvm.org/t/fp-can-we-add-pure-attribute-for-math-library-functions-default/79459,
math libcalls set errno, so it should emit "int" TBAA metadata on FP
libcalls to solve the alias issue.

Note: Only add support for expf in this PR

Fix llvm#86635
…action (llvm#73618)

Differential Revision: https://reviews.llvm.org/D150525

Implements:
- https://wg21.link/P1132R8 - `out_ptr` - a scalable output pointer
abstraction
- https://eel.is/c++draft/smartptr.adapt - 20.3.4 Smart pointer adaptors
- https://wg21.link/LWG3734 - Inconsistency in `inout_ptr` and `out_ptr`
for empty case
- https://wg21.link/LWG3897- `inout_ptr` will not update raw pointer to
0

---------

Co-authored-by: Hristo Hristov <[email protected]>
Detect and support fixed PIC indirect jumps of the following form:
```
movslq  En(%rip), %r1
leaq  PIC_JUMP_TABLE(%rip), %r2
addq  %r2, %r1
jmpq  *%r1
```

with PIC_JUMP_TABLE that looks like following:

```
  JT:  ----------
   E1:| L1 - JT  |
      |----------|
   E2:| L2 - JT  |
      |----------|
      |          |
         ......
   En:| Ln - JT  |
       ----------
```

The code could be produced by compilers, see
llvm#91648.

Test Plan: updated jump-table-fixed-ref-pic.test

Reviewers: maksfb, ayermolo, dcci, rafaelauler

Reviewed By: rafaelauler

Pull Request: llvm#91667
Add a BinaryFunction field for pseudo probe function GUID.
Populate it during pseudo probe section parsing, and emit it in YAML
profile (both regular and BAT), along with function checksum.

To be used for stale function matching.

Test Plan: update pseudoprobe-decoding-inline.test
AddressProbesMap is keyed by binary addresses, and it makes sense to
treat them as ordered. This also enables slicing by binary function/
binary basic block, to be used in BOLT
(llvm#99554).

Test Plan: NFC

Reviewers: wlei-llvm

Reviewed By: wlei-llvm

Pull Request: llvm#99553
Read pseudo probes in regular and BAT YAML profile generation, and
attach them to YAML profile basic blocks. This exposes GUID, probe id,
and probe type in profile for future use in stale profile matching.

Test Plan: updated pseudoprobe-decoding-inline.test

Reviewers: dcci, rafaelauler, ayermolo, maksfb

Reviewed By: rafaelauler

Pull Request: llvm#99554
…puting leading zeros (llvm#99524)

It turns out we can safely use
DAG.computeKnownBits(N0).countMinLeadingZeros() with constant legal
vectors, so remove the check for it.
This is follow-up for llvm#78901 after validation.
Drop the comments for stability since zu is the last feature for cpuid APX_F.
…lueType (llvm#99537)

The original `CheckValueTypeMatcher` stores StringRef as the member
variable type, however it's more efficient to use use
MVT::SimpleValueType since it prevents string comparison in isEqualImpl,
it also reduce the memory consumption in each object.
banach-space and others added 18 commits July 21, 2024 17:44
Documents which patterns are tested in:
  * vector-transfer-collapse-inner-most-dims.mlir.
In bolt/lib/Passes/AsmDump.cpp, the MCInstPrinter is created with false
AsmVerbose. The AsmVerbose argument to createAsmStreamer is unused.

Deprecate the legacy Target::createAsmStreamer overload, which might be
used by downstream.
…sVerboseAsm()

... to improve consistency. Most targets don't use VerboseAsm. When they
do (X86, SystemZ), they use MCStreamer::isVerboseAsm().
…orTy

The parameter is confusing as it duplicates MCStreamer::isVeboseAsm
(initialized from MCTargetOptions::AsmVerbose). After
233cca1, no in-tree target uses the
parameter.
They currently get the header from MCLinkerOptimizationHint.h, which
will be removed from MCAssembler.h.
…race" (llvm#99757)

Reverts llvm#99731

Remove accidentally added temporary file.
Also, fix the uninitialized read of line number.
llvm#99465)

… architecture

On 32 bit systems, TypeParameterValue is 64bit wide while CFI_index_t is
32bit wide.
…eamer

Similar to commit 28fcafb (2011) for
MachObjectWriter. MCWinCOFFStreamer can now access WinCOFFObjectWriter
directly without holding object file format specific inforamtion in
MCAssembler (e.g. IncrementalLinkerCompatible).
We need to distinguish ShapedTypes with and without value semantics.
This is needed for downstream users to define their custom vector and
tensor
types that can work with the arith/math dialect.

RFC https://discourse.llvm.org/t/rfc-mlir-types-with-encoding/80189
tcreech-intel pushed a commit that referenced this pull request Jul 21, 2024
This patch adds a frame recognizer for Clang's
`__builtin_verbose_trap`, which behaves like a
`__builtin_trap`, but emits a failure-reason string into debug-info in
order for debuggers to display
it to a user.

The frame recognizer triggers when we encounter
a frame with a function name that begins with
`__clang_trap_msg`, which is the magic prefix
Clang emits into debug-info for verbose traps.
Once such frame is encountered we display the
frame function name as the `Stop Reason` and display that frame to the
user.

Example output:
```
(lldb) run
warning: a.out was compiled with optimization - stepping may behave oddly; variables may not be available.
Process 35942 launched: 'a.out' (arm64)
Process 35942 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
    frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
   1    struct Dummy {
   2      void func() {
-> 3        __builtin_verbose_trap("Misc.", "Function is not implemented");
   4      }
   5    };
   6
   7    int main() {
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
    frame #0: 0x0000000100003fa4 a.out`main [inlined] __clang_trap_msg$Misc.$Function is not implemented$ at verbose_trap.cpp:0 [opt]
  * frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
    frame llvm#2: 0x0000000100003fa4 a.out`main at verbose_trap.cpp:8:13 [opt]
    frame llvm#3: 0x0000000189d518b4 dyld`start + 1988
```
Without `--sample-period`, no assumptions are made about perf profile
sample frequencies. This is useful for comparing relative hotness
of different program locations within the same profile.

With `--sample-period`, LBR- and IP-based profile hit counts are
adjusted to estimate the absolute total event count for each program
location. This makes it reasonable to compare hit counts between
different profiles, e.g., between LBR-based execution frequency
profiles and IP-based branch mispredict profiles.
tcreech-intel pushed a commit that referenced this pull request Jul 27, 2024
…linux (llvm#99613)

Examples of the output:

ARM:
```
# ./a.out 
AddressSanitizer:DEADLYSIGNAL
=================================================================
==122==ERROR: AddressSanitizer: SEGV on unknown address 0x0000007a (pc 0x76e13ac0 bp 0x7eb7fd00 sp 0x7eb7fcc8 T0)
==122==The signal is caused by a READ memory access.
==122==Hint: address points to the zero page.
    #0 0x76e13ac0  (/lib/libc.so.6+0x7cac0)
    #1 0x76dce680 in gsignal (/lib/libc.so.6+0x37680)
    llvm#2 0x005c2250  (/root/a.out+0x145250)
    llvm#3 0x76db982c  (/lib/libc.so.6+0x2282c)
    llvm#4 0x76db9918 in __libc_start_main (/lib/libc.so.6+0x22918)

==122==Register values:
 r0 = 0x00000000   r1 = 0x0000007a   r2 = 0x0000000b   r3 = 0x76d95020  
 r4 = 0x0000007a   r5 = 0x00000001   r6 = 0x005dcc5c   r7 = 0x0000010c  
 r8 = 0x0000000b   r9 = 0x76f9ece0  r10 = 0x00000000  r11 = 0x7eb7fd00  
r12 = 0x76dce670   sp = 0x7eb7fcc8   lr = 0x76e13ab4   pc = 0x76e13ac0  
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/lib/libc.so.6+0x7cac0) 
==122==ABORTING
```

AArch64:
```
# ./a.out 
UndefinedBehaviorSanitizer:DEADLYSIGNAL
==99==ERROR: UndefinedBehaviorSanitizer: SEGV on unknown address 0x000000000063 (pc 0x007fbbbc5860 bp 0x007fcfdcb700 sp 0x007fcfdcb700 T99)
==99==The signal is caused by a UNKNOWN memory access.
==99==Hint: address points to the zero page.
    #0 0x007fbbbc5860  (/lib64/libc.so.6+0x82860)
    #1 0x007fbbb81578  (/lib64/libc.so.6+0x3e578)
    llvm#2 0x00556051152c  (/root/a.out+0x3152c)
    llvm#3 0x007fbbb6e268  (/lib64/libc.so.6+0x2b268)
    llvm#4 0x007fbbb6e344  (/lib64/libc.so.6+0x2b344)
    llvm#5 0x0055604e45ec  (/root/a.out+0x45ec)

==99==Register values:
 x0 = 0x0000000000000000   x1 = 0x0000000000000063   x2 = 0x000000000000000b   x3 = 0x0000007fbbb41440  
 x4 = 0x0000007fbbb41580   x5 = 0x3669288942d44cce   x6 = 0x0000000000000000   x7 = 0x00000055605110b0  
 x8 = 0x0000000000000083   x9 = 0x0000000000000000  x10 = 0x0000000000000000  x11 = 0x0000000000000000  
x12 = 0x0000007fbbdb3360  x13 = 0x0000000000010000  x14 = 0x0000000000000039  x15 = 0x00000000004113a0  
x16 = 0x0000007fbbb81560  x17 = 0x0000005560540138  x18 = 0x000000006474e552  x19 = 0x0000000000000063  
x20 = 0x0000000000000001  x21 = 0x000000000000000b  x22 = 0x0000005560511510  x23 = 0x0000007fcfdcb918  
x24 = 0x0000007fbbdb1b50  x25 = 0x0000000000000000  x26 = 0x0000007fbbdb2000  x27 = 0x000000556053f858  
x28 = 0x0000000000000000   fp = 0x0000007fcfdcb700   lr = 0x0000007fbbbc584c   sp = 0x0000007fcfdcb700  
UndefinedBehaviorSanitizer can not provide additional info.
SUMMARY: UndefinedBehaviorSanitizer: SEGV (/lib64/libc.so.6+0x82860) 
==99==ABORTING
```
tcreech-intel pushed a commit that referenced this pull request Aug 15, 2024
```
  UBSan-Standalone-sparc :: TestCases/Misc/Linux/diag-stacktrace.cpp
```
`FAIL`s on 32 and 64-bit Linux/sparc64 (and on Solaris/sparcv9, too: the
test isn't Linux-specific at all). With
`UBSAN_OPTIONS=fast_unwind_on_fatal=1`, the stack trace shows a
duplicate innermost frame:
```
compiler-rt/test/ubsan/TestCases/Misc/Linux/diag-stacktrace.cpp:14:31: runtime error: execution reached the end of a value-returning function without returning a value
    #0 0x7003a708 in f() compiler-rt/test/ubsan/TestCases/Misc/Linux/diag-stacktrace.cpp:14:35
    #1 0x7003a708 in f() compiler-rt/test/ubsan/TestCases/Misc/Linux/diag-stacktrace.cpp:14:35
    llvm#2 0x7003a714 in g() compiler-rt/test/ubsan/TestCases/Misc/Linux/diag-stacktrace.cpp:17:38
```
which isn't seen with `fast_unwind_on_fatal=0`.

This turns out to be another fallout from fixing
`__builtin_return_address`/`__builtin_extract_return_addr` on SPARC. In
`sanitizer_stacktrace_sparc.cpp` (`BufferedStackTrace::UnwindFast`) the
`pc` arg is the return address, while `pc1` from the stack frame
(`fr_savpc`) is the address of the `call` insn, leading to a double
entry for the innermost frame in `trace_buffer[]`.

This patch fixes this by moving the adjustment before all uses.

Tested on `sparc64-unknown-linux-gnu` and `sparcv9-sun-solaris2.11`
(with the `ubsan/TestCases/Misc/Linux` tests enabled).
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
Otherwise debug-info is stripped, which influences the language of the
current frame.

Also, set explicit breakpoint because Windows seems to not obey the
debugtrap.

Log from failing test on Windows:
```
(lldb) command source -s 0 'lit-lldb-init-quiet'
Executing commands in 'D:\test\lit-lldb-init-quiet'.
(lldb) command source -C --silent-run true lit-lldb-init
(lldb) target create "main.out"
Current executable set to 'D:\test\main.out' (x86_64).
(lldb) settings set interpreter.stop-command-source-on-error false
(lldb) command source -s 0 'with-target.input'
Executing commands in 'D:\test\with-target.input'.
(lldb) expr blah
            ^
            error: use of undeclared identifier 'blah'
note: Falling back to default language. Ran expression as 'Objective C++'.
(lldb) run
Process 29404 launched: 'D:\test\main.out' (x86_64)
Process 29404 stopped
* thread #1, stop reason = Exception 0x80000003 encountered at address 0x7ff7b3df7189
    frame #0: 0x00007ff7b3df718a main.out
->  0x7ff7b3df718a: xorl   %eax, %eax
    0x7ff7b3df718c: popq   %rcx
    0x7ff7b3df718d: retq
    0x7ff7b3df718e: int3
(lldb) expr blah
            ^
            error: use of undeclared identifier 'blah'
note: Falling back to default language. Ran expression as 'Objective C++'.
(lldb) expr -l objc -- blah
                       ^
                       error: use of undeclared identifier 'blah'
note: Expression evaluation in pure Objective-C not supported. Ran expression as 'Objective C++'.
(lldb) expr -l c -- blah
                    ^
                    error: use of undeclared identifier 'blah'
note: Expression evaluation in pure C not supported. Ran expression as 'ISO C++'.
```
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
The Tkinter module was renamed to tkinter in Python 3.0.

https://docs.python.org/2/library/tkinter.html
https://docs.python.org/3/library/tkinter.html

Rest of it appears to work when imported inside of LLDB:
```
$ ./bin/lldb /tmp/test.o
(lldb) target create "/tmp/test.o"
Current executable set to '/tmp/test.o' (x86_64).
(lldb) b main
Breakpoint 1: where = test.o`main + 8 at test.c:1:18, address = 0x0000000000001131
(lldb) run
Process 121572 launched: '/tmp/test.o' (x86_64)
Process 121572 stopped
* thread #1, name = 'test.o', stop reason = breakpoint 1.1
    frame #0: 0x0000555555555131 test.o`main at test.c:1:18
-> 1   	int main() { int a = 1; char b = '?'; return 0; }
(lldb) command script import <...>/llvm-project/lldb/examples/python/lldbtk.py
(lldb) tk-
Available completions:
        tk-process   -- For more information run 'help tk-process'
        tk-target    -- For more information run 'help tk-target'
        tk-variables -- For more information run 'help tk-variables'
(lldb) tk-process
(lldb) tk-target
(lldb) tk-variables
```
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
…ypes (llvm#162278)

When we take the following C program:
```
int main() {
  return 0;
}
```
and create a statically-linked executable from it:
```
clang -static -g -o main main.c
```
Then we can observe the following `lldb` behavior:
```
$ lldb
(lldb) target create main
Current executable set to '.../main' (x86_64).
(lldb) breakpoint set --name main
Breakpoint 1: where = main`main + 11 at main.c:2:3, address = 0x000000000022aa7b
(lldb) process launch
Process 3773637 launched: '/home/me/tmp/built-in/main' (x86_64)
Process 3773637 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000000000022aa7b main`main at main.c:2:3
   1   	int main() {
-> 2   	  return 0;
   3   	}
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("__int128").size
0
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("unsigned __int128").size
0
(lldb) quit
```
The value return by the `SBTarget::FindFirstType` method is wrong for
the `__int128` and `unsigned __int128` basic types.

The proposed changes make the `TypeSystemClang::GetBasicTypeEnumeration`
method consistent with `gcc` and `clang` C [language
extension](https://gcc.gnu.org/onlinedocs/gcc/_005f_005fint128.html)
related to 128-bit integer types as well as with the
`BuiltinType::getName` method in the LLVM codebase itself.

When the above change is applied, the behavior of the `lldb` changes in
the following (desired) way:
```
$ lldb
(lldb) target create main
Current executable set to '.../main' (x86_64).
(lldb) breakpoint set --name main
Breakpoint 1: where = main`main + 11 at main.c:2:3, address = 0x000000000022aa7b
(lldb) process launch
Process 3773637 launched: '/home/me/tmp/built-in/main' (x86_64)
Process 3773637 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000000000022aa7b main`main at main.c:2:3
   1   	int main() {
-> 2   	  return 0;
   3   	}
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("__int128").size
16
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("unsigned __int128").size
16
(lldb) quit
```

---------

Co-authored-by: Matej Košík <[email protected]>
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
**Mitigation for:** google/sanitizers#749

**Disclosure:** I'm not an ASan compiler expert yet (I'm trying to
learn!), I primarily work in the runtime. Some of this PR was developed
with the help of AI tools (primarily as a "fuzzy `grep` engine"), but
I've manually refined and tested the output, and can speak for every
line. In general, I used it only to orient myself and for
"rubberducking".

**Context:**

The msvc ASan team (👋 ) has received an internal request to improve
clang's exception handling under ASan for Windows. Namely, we're
interested in **mitigating** this bug:
google/sanitizers#749

To summarize, today, clang + ASan produces a false-positive error for
this program:

```C++
#include <cstdio>
#include <exception>
int main()
{
	try	{
		throw std::exception("test");
	}catch (const std::exception& ex){
		puts(ex.what());
	}
	return 0;
}
```

The error reads as such:


```
C:\Users\dajusto\source\repros\upstream>type main.cpp
#include <cstdio>
#include <exception>
int main()
{
        try     {
                throw std::exception("test");
        }catch (const std::exception& ex){
                puts(ex.what());
        }
        return 0;
}
C:\Users\dajusto\source\repros\upstream>"C:\Users\dajusto\source\repos\llvm-project\build.runtimes\bin\clang.exe" -fsanitize=address -g -O0 main.cpp

C:\Users\dajusto\source\repros\upstream>a.exe
=================================================================
==19112==ERROR: AddressSanitizer: access-violation on unknown address 0x000000000000 (pc 0x7ff72c7c11d9 bp 0x0080000ff960 sp 0x0080000fcf50 T0)
==19112==The signal is caused by a READ memory access.
==19112==Hint: address points to the zero page.
    #0 0x7ff72c7c11d8 in main C:\Users\dajusto\source\repros\upstream\main.cpp:8
    #1 0x7ff72c7d479f in _CallSettingFrame C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\amd64\handlers.asm:49
    llvm#2 0x7ff72c7c8944 in __FrameHandler3::CxxCallCatchBlock(struct _EXCEPTION_RECORD *) C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\frame.cpp:1567
    llvm#3 0x7ffb4a90e3e5  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x18012e3e5)
    llvm#4 0x7ff72c7c1128 in main C:\Users\dajusto\source\repros\upstream\main.cpp:6
    llvm#5 0x7ff72c7c33db in invoke_main C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78
    llvm#6 0x7ff72c7c33db in __scrt_common_main_seh C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
    llvm#7 0x7ffb49b05c06  (C:\WINDOWS\System32\KERNEL32.DLL+0x180035c06)
    llvm#8 0x7ffb4a8455ef  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800655ef)

==19112==Register values:
rax = 0  rbx = 80000ff8e0  rcx = 27d76d00000  rdx = 80000ff8e0
rdi = 80000fdd50  rsi = 80000ff6a0  rbp = 80000ff960  rsp = 80000fcf50
r8  = 100  r9  = 19930520  r10 = 8000503a90  r11 = 80000fd540
r12 = 80000fd020  r13 = 0  r14 = 80000fdeb8  r15 = 0
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: access-violation C:\Users\dajusto\source\repros\upstream\main.cpp:8 in main
==19112==ABORTING
```

The root of the issue _appears to be_ that ASan's instrumentation is
incompatible with Window's assumptions for instantiating `catch`-block's
parameters (`ex` in the snippet above).

The nitty gritty details are lost on me, but I understand that to make
this work without loss of ASan coverage, a "serious" refactoring is
needed. In the meantime, users risk false positive errors when pairing
ASan + catch-block parameters on Windows.

**To mitigate this** I think we should avoid instrumenting catch-block
parameters on Windows. It appears to me this is as "simple" as marking
catch block parameters as "uninteresting" in
`AddressSanitizer::isInterestingAlloca`. My manual tests seem to confirm
this.

I believe this is strictly better than today's status quo, where the
runtime generates false positives. Although we're now explicitly
choosing to instrument less, the benefit is that now more programs can
run with ASan without _funky_ macros that disable ASan on exception
blocks.

**This PR:** implements the mitigation above, and creates a simple new
test for it.

_Thanks!_

---------

Co-authored-by: Antonio Frighetto <[email protected]>
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
…nteger registers (llvm#163646)

Fix the `RegisterValue::SetValueFromData` method so that it works also
for 128-bit registers that contain integers.

Without this change, the `RegisterValue::SetValueFromData` method does
not work correctly
for 128-bit registers that contain (signed or unsigned) integers.

---

Steps to reproduce the problem:

(1)

Create a program that writes a 128-bit number to a 128-bit registers
`xmm0`. E.g.:
```
#include <stdint.h>

int main() {
  __asm__ volatile (
      "pinsrq $0, %[lo], %%xmm0\n\t"  // insert low 64 bits
      "pinsrq $1, %[hi], %%xmm0"    // insert high 64 bits
      :
      : [lo]"r"(0x7766554433221100),
        [hi]"r"(0xffeeddccbbaa9988)
  );
  return 0;
}
```

(2)

Compile this program with LLVM compiler:
```
$ $YOUR/clang -g -o main main.c
```

(3)

Modify LLDB so that when it will be reading value from the `xmm0`
register, instead of assuming that it is vector register, it will treat
it as if it contain an integer. This can be achieved e.g. this way:
```
diff --git a/lldb/source/Utility/RegisterValue.cpp b/lldb/source/Utility/RegisterValue.cpp
index 0e99451..a4b51db3e56d 100644
--- a/lldb/source/Utility/RegisterValue.cpp
+++ b/lldb/source/Utility/RegisterValue.cpp
@@ -188,6 +188,7 @@ Status RegisterValue::SetValueFromData(const RegisterInfo &reg_info,
     break;
   case eEncodingUint:
   case eEncodingSint:
+  case eEncodingVector:
     if (reg_info.byte_size == 1)
       SetUInt8(src.GetMaxU32(&src_offset, src_len));
     else if (reg_info.byte_size <= 2)
@@ -217,23 +218,6 @@ Status RegisterValue::SetValueFromData(const RegisterInfo &reg_info,
     else if (reg_info.byte_size == sizeof(long double))
       SetLongDouble(src.GetLongDouble(&src_offset));
     break;
-  case eEncodingVector: {
-    m_type = eTypeBytes;
-    assert(reg_info.byte_size <= kMaxRegisterByteSize);
-    buffer.bytes.resize(reg_info.byte_size);
-    buffer.byte_order = src.GetByteOrder();
-    if (src.CopyByteOrderedData(
-            src_offset,          // offset within "src" to start extracting data
-            src_len,             // src length
-            buffer.bytes.data(), // dst buffer
-            buffer.bytes.size(), // dst length
-            buffer.byte_order) == 0) // dst byte order
-    {
-      error = Status::FromErrorStringWithFormat(
-          "failed to copy data for register write of %s", reg_info.name);
-      return error;
-    }
-  }
   }
 
   if (m_type == eTypeInvalid)
```

(4)

Rebuild the LLDB.

(5)

Observe what happens how LLDB will print the content of this register
after it was initialized with 128-bit value.
```
$YOUR/lldb --source ./main
(lldb) target create main
Current executable set to '.../main' (x86_64).
(lldb) breakpoint set --file main.c --line 11
Breakpoint 1: where = main`main + 45 at main.c:11:3, address = 0x000000000000164d
(lldb) settings set stop-line-count-before 20
(lldb) process launch
Process 2568735 launched: '.../main' (x86_64)
Process 2568735 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000055555555564d main`main at main.c:11:3
   1   	#include <stdint.h>
   2   	
   3   	int main() {
   4   	  __asm__ volatile (
   5   	      "pinsrq $0, %[lo], %%xmm0\n\t"  // insert low 64 bits
   6   	      "pinsrq $1, %[hi], %%xmm0"    // insert high 64 bits
   7   	      :
   8   	      : [lo]"r"(0x7766554433221100),
   9   	        [hi]"r"(0xffeeddccbbaa9988)
   10  	  );
-> 11  	  return 0;
   12  	}
(lldb) register read --format hex xmm0
    xmm0 = 0x7766554433221100ffeeddccbbaa9988
```

You can see that the upper and lower 64-bit wide halves are swapped.

---------

Co-authored-by: Matej Košík <[email protected]>
tcreech-intel pushed a commit that referenced this pull request Oct 22, 2025
…lvm#162993)

Early if conversion can create instruction sequences such as
```
mov  x1, #1
csel x0, x1, x2, eq
```
which could be simplified into the following instead
```
csinc x0, x2, xzr, ne
```

One notable example that generates code like this is `cmpxchg weak`.

This is fixed by handling an immediate value of 1 as `add(wzr, 1)` so
that the addition can be folded into CSEL by using CSINC instead.
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