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llvm / llvm-project / c27e283cfbca2bd22f34592430e98ee76ed60ad8
commitc27e283cfbca2bd22f34592430e98ee76ed60ad8[log] [tgz]
authorYexuanXiao <bizwen@nykz.org>Fri Jul 18 09:45:57 2025 +0800
committerGitHub <noreply@github.com>Thu Jul 17 22:45:57 2025 -0300
tree5f8e23eeadff53a72e3871720737c84771dcbc2c
parentbaa291bfb58e73a253669b86ac604cf8e6792b6c [diff]
[Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (#143653)

Including the results of `sizeof`, `sizeof...`, `__datasizeof`,
`__alignof`, `_Alignof`, `alignof`, `_Countof`, `size_t` literals, and
signed `size_t` literals, the results of pointer-pointer subtraction and
checks for standard library functions (and their calls).

The goal is to enable clang and downstream tools such as clangd and
clang-tidy to provide more portable hints and diagnostics.

The previous discussion can be found at #136542.

This PR implements this feature by introducing a new subtype of `Type`
called `PredefinedSugarType`, which was considered appropriate in
discussions. I tried to keep `PredefinedSugarType` simple enough yet not
limited to `size_t` and `ptrdiff_t` so that it can be used for other
purposes. `PredefinedSugarType` wraps a canonical `Type` and provides a
name, conceptually similar to a compiler internal `TypedefType` but
without depending on a `TypedefDecl` or a source file.

Additionally, checks for the `z` and `t` format specifiers in format
strings for `scanf` and `printf` were added. It will precisely match
expressions using `typedef`s or built-in expressions.

The affected tests indicates that it works very well.

Several code require that `SizeType` is canonical, so I kept `SizeType`
to its canonical form.

The failed tests in CI are allowed to fail. See the
[comment](https://github.com/llvm/llvm-project/pull/135386#issuecomment-3049426611)
in another PR #135386.
85 files changed
tree: 5f8e23eeadff53a72e3871720737c84771dcbc2c
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-format-ignore
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
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