933ad5c897
Watchpoints in lldb can be either 'read', 'write', or 'read/write'. This is exposing the actual behavior of hardware watchpoints. gdb has a different behavior: a "write" type watchpoint only stops when the watched memory region *changes*. A user is using a watchpoint for one of three reasons: 1. Want to find what is changing/corrupting this memory. 2. Want to find what is writing to this memory. 3. Want to find what is reading from this memory. I believe (1) is the most common use case for watchpoints, and it currently can't be done in lldb -- the user needs to continue every time the same value is written to the watched-memory manually. I think gdb's behavior is the correct one. There are some use cases where a developer wants to find every function that writes/reads to/from a memory region, regardless of value, I want to still allow that functionality. This is also a bit of groundwork for my large watchpoint support proposal https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116 where I will be adding support for AArch64 MASK watchpoints which watch power-of-2 memory regions. A user might ask to watch 24 bytes, and a MASK watchpoint stub can do this with a 32-byte MASK watchpoint if it is properly aligned. And we need to ignore writes to the final 8 bytes of that watched region, and not show those hits to the user. This patch adds a new 'modify' watchpoint type and it is the default. Re-landing this patch after addressing testsuite failures found in CI on Linux, Intel machines, and windows. rdar://108234227 |
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| bolt | ||
| clang | ||
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| cmake | ||
| compiler-rt | ||
| cross-project-tests | ||
| flang | ||
| libc | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llvm | ||
| llvm-libgcc | ||
| mlir | ||
| openmp | ||
| polly | ||
| pstl | ||
| runtimes | ||
| third-party | ||
| utils | ||
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| .arclint | ||
| .clang-format | ||
| .clang-tidy | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| .mailmap | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| LICENSE.TXT | ||
| README.md | ||
| SECURITY.md | ||
The LLVM Compiler Infrastructure
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