[clang-tools-extra] 5a8d096 - [clang-tidy] Fix false positive for cppcoreguidelines-pro-bounds-pointer-arithmetic (#127394)
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cfe-commits at lists.llvm.org
Wed Jul 2 07:41:27 PDT 2025
Author: flovent
Date: 2025-07-02T17:41:24+03:00
New Revision: 5a8d096ae3443909bbcc87465653c15b58bc2e11
URL: https://github.com/llvm/llvm-project/commit/5a8d096ae3443909bbcc87465653c15b58bc2e11
DIFF: https://github.com/llvm/llvm-project/commit/5a8d096ae3443909bbcc87465653c15b58bc2e11.diff
LOG: [clang-tidy] Fix false positive for cppcoreguidelines-pro-bounds-pointer-arithmetic (#127394)
this PR fixes #126424
for `ArraySubScriptExpr`, `hasBase` Matcher will get right operand when
it is not integer type, but is not for sure that left operand is integer
type. For the example code below `hasBase` will get `r` for the
Subsequent matching and causing false positive.
```
template <typename R>
int f(std::map<R*, int>& map, R* r) {
return map[r];
}
```
so is needed to see if index is integer type to avoid this situation.
Added:
Modified:
clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
clang-tools-extra/docs/ReleaseNotes.rst
clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic.cpp
Removed:
################################################################################
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
index a1494a095f5b6..0d68790349fb5 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
@@ -42,7 +42,8 @@ void ProBoundsPointerArithmeticCheck::registerMatchers(MatchFinder *Finder) {
arraySubscriptExpr(
hasBase(ignoringImpCasts(
anyOf(AllPointerTypes,
- hasType(decayedType(hasDecayedType(pointerType())))))))
+ hasType(decayedType(hasDecayedType(pointerType())))))),
+ hasIndex(hasType(isInteger())))
.bind("expr"),
this);
}
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 8c331e0b0a403..198efee7754de 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -216,6 +216,11 @@ Changes in existing checks
<clang-tidy/checks/cppcoreguidelines/missing-std-forward>` check by adding a
flag to specify the function used for forwarding instead of ``std::forward``.
+- Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic
+ <clang-tidy/checks/cppcoreguidelines/pro-bounds-pointer-arithmetic>` check by
+ fixing false positives when calling indexing operators that do not perform
+ pointer arithmetic in template, for example ``std::map::operator[]``.
+
- Improved :doc:`cppcoreguidelines-rvalue-reference-param-not-moved
<clang-tidy/checks/cppcoreguidelines/rvalue-reference-param-not-moved>` check
by adding a flag to specify the function used for moving instead of
diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic.cpp
index 7cbc6ddf96ab6..7f69eddee03aa 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic.cpp
@@ -87,3 +87,25 @@ void okay() {
for(int ii : a) ; // OK, pointer arithmetic generated by compiler
}
+
+namespace gh126424 {
+
+namespace std {
+template <typename, typename>
+class pair {};
+
+template <typename Key, typename Value>
+class map {
+ public:
+ using value_type = pair<Key, Value>;
+ value_type& operator[](const Key& key);
+ value_type& operator[](Key&& key);
+ };
+}
+
+template <typename R>
+int f(std::map<R*, int>& map, R* r) {
+ return map[r]; // OK
+}
+
+}
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