[clang-tools-extra] [clang-tidy] Speed up `readability-container-contains` (PR #175121)
Victor Chernyakin via cfe-commits
cfe-commits at lists.llvm.org
Thu Jan 8 21:55:59 PST 2026
https://github.com/localspook created https://github.com/llvm/llvm-project/pull/175121
This is currently our most expensive check as measured by `--enable-check-profile`, tied with `altera-id-dependent-backward-branch`. I measured using [the usual setup](https://github.com/llvm/llvm-project/pull/174357#issue-3780188615):
```sh
hyperfine \
--shell=none \
--prepare='cmake --build build/release --target clang-tidy' \
'./build/release/bin/clang-tidy --checks=-*,readability-container-contains all_headers.cpp -header-filter=.* -system-headers -- -std=c++23 -fno-delayed-template-parsing'
```
First, the status quo:
```txt
Time (mean ± σ): 5.243 s ± 0.158 s [User: 4.964 s, System: 0.248 s]
Range (min … max): 5.133 s … 5.612 s 10 runs
```
This PR improves that in two independent commits. The first commit changes the default traversal mode from `TK_AsIs` to `TK_IgnoreUnlessSpelledInSource`. Result:
```txt
Time (mean ± σ): 4.554 s ± 0.100 s [User: 4.273 s, System: 0.248 s]
Range (min … max): 4.442 s … 4.785 s 10 runs
```
The second commit merges all 12 of the check's `BinaryOperation` matchers into one, because I found that simply registering a `BinaryOperation` matcher has pretty extreme overhead. Result:
```txt
Time (mean ± σ): 3.480 s ± 0.121 s [User: 3.264 s, System: 0.186 s]
Range (min … max): 3.400 s … 3.798 s 10 runs
```
>From f5d0a216674c1dbf054eb84c6301297afad4a0d2 Mon Sep 17 00:00:00 2001
From: Victor Chernyakin <chernyakin.victor.j at outlook.com>
Date: Thu, 8 Jan 2026 18:36:50 -0800
Subject: [PATCH 1/2] Set TK_IgnoreUnlessSpelledInSource as the default
---
.../readability/ContainerContainsCheck.cpp | 82 +++++++++++--------
.../readability/ContainerContainsCheck.h | 2 +-
2 files changed, 47 insertions(+), 37 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
index efcf13d63b4ff..6fe49cfe53a89 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
@@ -47,57 +47,67 @@ void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
const auto StringNpos = anyOf(declRefExpr(to(varDecl(hasName("npos")))),
memberExpr(member(hasName("npos"))));
- auto AddSimpleMatcher = [&](const auto &Matcher) {
- Finder->addMatcher(traverse(TK_IgnoreUnlessSpelledInSource, Matcher), this);
- };
-
// Find membership tests which use `count()`.
- Finder->addMatcher(implicitCastExpr(hasImplicitDestinationType(booleanType()),
- hasSourceExpression(CountCall))
- .bind("positiveComparison"),
- this);
- AddSimpleMatcher(
+ Finder->addMatcher(
+ traverse(TK_AsIs,
+ implicitCastExpr(hasImplicitDestinationType(booleanType()),
+ hasSourceExpression(CountCall))
+ .bind("positiveComparison")),
+ this);
+ Finder->addMatcher(
binaryOperation(hasOperatorName("!="), hasOperands(CountCall, Literal0))
- .bind("positiveComparison"));
- AddSimpleMatcher(
+ .bind("positiveComparison"),
+ this);
+ Finder->addMatcher(
binaryOperation(hasLHS(CountCall), hasOperatorName(">"), hasRHS(Literal0))
- .bind("positiveComparison"));
- AddSimpleMatcher(
+ .bind("positiveComparison"),
+ this);
+ Finder->addMatcher(
binaryOperation(hasLHS(Literal0), hasOperatorName("<"), hasRHS(CountCall))
- .bind("positiveComparison"));
- AddSimpleMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName(">="),
- hasRHS(Literal1))
- .bind("positiveComparison"));
- AddSimpleMatcher(binaryOperation(hasLHS(Literal1), hasOperatorName("<="),
- hasRHS(CountCall))
- .bind("positiveComparison"));
+ .bind("positiveComparison"),
+ this);
+ Finder->addMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName(">="),
+ hasRHS(Literal1))
+ .bind("positiveComparison"),
+ this);
+ Finder->addMatcher(binaryOperation(hasLHS(Literal1), hasOperatorName("<="),
+ hasRHS(CountCall))
+ .bind("positiveComparison"),
+ this);
// Find inverted membership tests which use `count()`.
- AddSimpleMatcher(
+ Finder->addMatcher(
binaryOperation(hasOperatorName("=="), hasOperands(CountCall, Literal0))
- .bind("negativeComparison"));
- AddSimpleMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName("<="),
- hasRHS(Literal0))
- .bind("negativeComparison"));
- AddSimpleMatcher(binaryOperation(hasLHS(Literal0), hasOperatorName(">="),
- hasRHS(CountCall))
- .bind("negativeComparison"));
- AddSimpleMatcher(
+ .bind("negativeComparison"),
+ this);
+ Finder->addMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName("<="),
+ hasRHS(Literal0))
+ .bind("negativeComparison"),
+ this);
+ Finder->addMatcher(binaryOperation(hasLHS(Literal0), hasOperatorName(">="),
+ hasRHS(CountCall))
+ .bind("negativeComparison"),
+ this);
+ Finder->addMatcher(
binaryOperation(hasLHS(CountCall), hasOperatorName("<"), hasRHS(Literal1))
- .bind("negativeComparison"));
- AddSimpleMatcher(
+ .bind("negativeComparison"),
+ this);
+ Finder->addMatcher(
binaryOperation(hasLHS(Literal1), hasOperatorName(">"), hasRHS(CountCall))
- .bind("negativeComparison"));
+ .bind("negativeComparison"),
+ this);
// Find membership tests based on `find() == end()` or `find() == npos`.
- AddSimpleMatcher(
+ Finder->addMatcher(
binaryOperation(hasOperatorName("!="),
hasOperands(FindCall, anyOf(EndCall, StringNpos)))
- .bind("positiveComparison"));
- AddSimpleMatcher(
+ .bind("positiveComparison"),
+ this);
+ Finder->addMatcher(
binaryOperation(hasOperatorName("=="),
hasOperands(FindCall, anyOf(EndCall, StringNpos)))
- .bind("negativeComparison"));
+ .bind("negativeComparison"),
+ this);
}
void ContainerContainsCheck::check(const MatchFinder::MatchResult &Result) {
diff --git a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
index 8e058f20427fd..8d043910fc2ba 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.h
@@ -29,7 +29,7 @@ class ContainerContainsCheck : public ClangTidyCheck {
return LO.CPlusPlus;
}
std::optional<TraversalKind> getCheckTraversalKind() const override {
- return TK_AsIs;
+ return TK_IgnoreUnlessSpelledInSource;
}
};
>From 61bf69ea1158f07b82b2908e8fa4ba8d3315f9ff Mon Sep 17 00:00:00 2001
From: Victor Chernyakin <chernyakin.victor.j at outlook.com>
Date: Thu, 8 Jan 2026 19:28:56 -0800
Subject: [PATCH 2/2] Merge all `BinaryOperation` matchers into one
---
.../readability/ContainerContainsCheck.cpp | 74 ++++++-------------
1 file changed, 22 insertions(+), 52 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
index 6fe49cfe53a89..3b4113c4e2ed0 100644
--- a/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ContainerContainsCheck.cpp
@@ -14,6 +14,7 @@
using namespace clang::ast_matchers;
namespace clang::tidy::readability {
+
void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
const auto Literal0 = integerLiteral(equals(0));
const auto Literal1 = integerLiteral(equals(1));
@@ -47,66 +48,35 @@ void ContainerContainsCheck::registerMatchers(MatchFinder *Finder) {
const auto StringNpos = anyOf(declRefExpr(to(varDecl(hasName("npos")))),
memberExpr(member(hasName("npos"))));
- // Find membership tests which use `count()`.
Finder->addMatcher(
traverse(TK_AsIs,
implicitCastExpr(hasImplicitDestinationType(booleanType()),
hasSourceExpression(CountCall))
.bind("positiveComparison")),
this);
- Finder->addMatcher(
- binaryOperation(hasOperatorName("!="), hasOperands(CountCall, Literal0))
- .bind("positiveComparison"),
- this);
- Finder->addMatcher(
- binaryOperation(hasLHS(CountCall), hasOperatorName(">"), hasRHS(Literal0))
- .bind("positiveComparison"),
- this);
- Finder->addMatcher(
- binaryOperation(hasLHS(Literal0), hasOperatorName("<"), hasRHS(CountCall))
- .bind("positiveComparison"),
- this);
- Finder->addMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName(">="),
- hasRHS(Literal1))
- .bind("positiveComparison"),
- this);
- Finder->addMatcher(binaryOperation(hasLHS(Literal1), hasOperatorName("<="),
- hasRHS(CountCall))
- .bind("positiveComparison"),
- this);
-
- // Find inverted membership tests which use `count()`.
- Finder->addMatcher(
- binaryOperation(hasOperatorName("=="), hasOperands(CountCall, Literal0))
- .bind("negativeComparison"),
- this);
- Finder->addMatcher(binaryOperation(hasLHS(CountCall), hasOperatorName("<="),
- hasRHS(Literal0))
- .bind("negativeComparison"),
- this);
- Finder->addMatcher(binaryOperation(hasLHS(Literal0), hasOperatorName(">="),
- hasRHS(CountCall))
- .bind("negativeComparison"),
- this);
- Finder->addMatcher(
- binaryOperation(hasLHS(CountCall), hasOperatorName("<"), hasRHS(Literal1))
- .bind("negativeComparison"),
- this);
- Finder->addMatcher(
- binaryOperation(hasLHS(Literal1), hasOperatorName(">"), hasRHS(CountCall))
- .bind("negativeComparison"),
- this);
- // Find membership tests based on `find() == end()` or `find() == npos`.
- Finder->addMatcher(
- binaryOperation(hasOperatorName("!="),
- hasOperands(FindCall, anyOf(EndCall, StringNpos)))
- .bind("positiveComparison"),
- this);
+ const auto PositiveComparison =
+ anyOf(allOf(hasOperatorName("!="), hasOperands(CountCall, Literal0)),
+ allOf(hasLHS(CountCall), hasOperatorName(">"), hasRHS(Literal0)),
+ allOf(hasLHS(Literal0), hasOperatorName("<"), hasRHS(CountCall)),
+ allOf(hasLHS(CountCall), hasOperatorName(">="), hasRHS(Literal1)),
+ allOf(hasLHS(Literal1), hasOperatorName("<="), hasRHS(CountCall)),
+ allOf(hasOperatorName("!="),
+ hasOperands(FindCall, anyOf(EndCall, StringNpos))));
+
+ const auto NegativeComparison =
+ anyOf(allOf(hasOperatorName("=="), hasOperands(CountCall, Literal0)),
+ allOf(hasLHS(CountCall), hasOperatorName("<="), hasRHS(Literal0)),
+ allOf(hasLHS(Literal0), hasOperatorName(">="), hasRHS(CountCall)),
+ allOf(hasLHS(CountCall), hasOperatorName("<"), hasRHS(Literal1)),
+ allOf(hasLHS(Literal1), hasOperatorName(">"), hasRHS(CountCall)),
+ allOf(hasOperatorName("=="),
+ hasOperands(FindCall, anyOf(EndCall, StringNpos))));
+
Finder->addMatcher(
- binaryOperation(hasOperatorName("=="),
- hasOperands(FindCall, anyOf(EndCall, StringNpos)))
- .bind("negativeComparison"),
+ binaryOperation(
+ anyOf(allOf(PositiveComparison, expr().bind("positiveComparison")),
+ allOf(NegativeComparison, expr().bind("negativeComparison")))),
this);
}
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