[PATCH] D45050: [clang-tidy] New checker for not null-terminated result caused by strlen or wcslen

[Csaba Dabis via Phabricator via cfe-commits]

Charusso updated this revision to Diff 157916.
Charusso added a comment.

Excuse me for the huge patch, but what I can done wrongly, I did, so I have made tons of revision.

I would like to show the current direction of the checker. Currently it has too much overlapping function, so please don't go too deep into the core.

Major fixes in every function:

- Equal length of `strlen(src)` is now handled.
- It can read out the length of the destination buffer.
- If the length increases in the passed argument, it also increases the destination buffer (if overflow is looks like to possible).

Major fixes in `memcpy()` and `memmove()`:

- It can decide which function is the best in performance and safety. (The last implementation was rely on C++11 version, which was a huge mistake.)
- Handles cases where the destination is `unsigned char` or `signed char`, which cannot be passed to any string handler function. (It haven't checked the type so that made wrong fix-its.)

Minor fixes:

- Removed all memory allocation matchers in general, but the current functions behave the same to increase the buffer length.
- Now the test files' `RUN` command working well. (CheckOptions was wrong.)

Problematic:

1. It allows all custom memory allocation function. Sometimes the read buffer size is not the size parameter.
2. May it is not a good idea to heuristically read and increase buffer lengths.
3. If the new function transformed from `memcpy()` to `strncpy()`, the checker adds the null terminator expression in the next line, like `dest[length] = '\0'`, which is looks like a quite big injection.


https://reviews.llvm.org/D45050

Files:
  clang-tidy/bugprone/BugproneTidyModule.cpp
  clang-tidy/bugprone/CMakeLists.txt
  clang-tidy/bugprone/NotNullTerminatedResultCheck.cpp
  clang-tidy/bugprone/NotNullTerminatedResultCheck.h
  docs/ReleaseNotes.rst
  docs/clang-tidy/checks/bugprone-not-null-terminated-result.rst
  docs/clang-tidy/checks/list.rst
  test/clang-tidy/bugprone-not-null-terminated-result-in-initialization-strlen.c
  test/clang-tidy/bugprone-not-null-terminated-result-memcpy-before-safe.c
  test/clang-tidy/bugprone-not-null-terminated-result-memcpy-safe-cxx.cpp
  test/clang-tidy/bugprone-not-null-terminated-result-memcpy-safe-other.c
  test/clang-tidy/bugprone-not-null-terminated-result-memcpy-safe.c
  test/clang-tidy/bugprone-not-null-terminated-result-strlen.c
  test/clang-tidy/bugprone-not-null-terminated-result-wcslen.cpp
  test/clang-tidy/bugprone-not-null-terminated-result-wmemcpy-safe-cxx.cpp

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