[clang-tidy] readability-function-size: add NestingThreshold param.
Summary:
Finds compound statements which create next nesting level after `NestingThreshold` and emits a warning.
Do note that it warns about each compound statement that breaches the threshold, but not any of it's sub-statements, to have readable warnings.
I was able to find only one coding style referencing nesting:
- https://www.kernel.org/doc/html/v4.10/process/coding-style.html#indentation
> In short, 8-char indents make things easier to read, and have the added benefit of warning you when you’re nesting your functions too deep.
This seems too basic, i'm not sure what else to test. Are more tests needed?
Reviewers: alexfh, aaron.ballman, sbenza
Reviewed By: alexfh, aaron.ballman
Subscribers: xazax.hun
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32942
llvm-svn: 305082
diff --git a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
index c48b513..51b1684 100644
--- a/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp
@@ -38,6 +38,13 @@
++Info.Branches;
// fallthrough
case Stmt::CompoundStmtClass:
+ // If this new compound statement is located in a compound statement,
+ // which is already nested NestingThreshold levels deep, record the start
+ // location of this new compound statement
+ if (CurrentNestingLevel == Info.NestingThreshold)
+ Info.NestingThresholders.push_back(Node->getLocStart());
+
+ ++CurrentNestingLevel;
TrackedParent.push_back(true);
break;
default:
@@ -47,7 +54,10 @@
Base::TraverseStmt(Node);
+ if (TrackedParent.back())
+ --CurrentNestingLevel;
TrackedParent.pop_back();
+
return true;
}
@@ -59,13 +69,15 @@
}
struct FunctionInfo {
- FunctionInfo() : Lines(0), Statements(0), Branches(0) {}
- unsigned Lines;
- unsigned Statements;
- unsigned Branches;
+ unsigned Lines = 0;
+ unsigned Statements = 0;
+ unsigned Branches = 0;
+ unsigned NestingThreshold = 0;
+ std::vector<SourceLocation> NestingThresholders;
};
FunctionInfo Info;
std::vector<bool> TrackedParent;
+ unsigned CurrentNestingLevel = 0;
};
FunctionSizeCheck::FunctionSizeCheck(StringRef Name, ClangTidyContext *Context)
@@ -73,13 +85,15 @@
LineThreshold(Options.get("LineThreshold", -1U)),
StatementThreshold(Options.get("StatementThreshold", 800U)),
BranchThreshold(Options.get("BranchThreshold", -1U)),
- ParameterThreshold(Options.get("ParameterThreshold", -1U)) {}
+ ParameterThreshold(Options.get("ParameterThreshold", -1U)),
+ NestingThreshold(Options.get("NestingThreshold", -1U)) {}
void FunctionSizeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "LineThreshold", LineThreshold);
Options.store(Opts, "StatementThreshold", StatementThreshold);
Options.store(Opts, "BranchThreshold", BranchThreshold);
Options.store(Opts, "ParameterThreshold", ParameterThreshold);
+ Options.store(Opts, "NestingThreshold", NestingThreshold);
}
void FunctionSizeCheck::registerMatchers(MatchFinder *Finder) {
@@ -90,6 +104,7 @@
const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
FunctionASTVisitor Visitor;
+ Visitor.Info.NestingThreshold = NestingThreshold;
Visitor.TraverseDecl(const_cast<FunctionDecl *>(Func));
auto &FI = Visitor.Info;
@@ -109,7 +124,8 @@
if (FI.Lines > LineThreshold || FI.Statements > StatementThreshold ||
FI.Branches > BranchThreshold ||
- ActualNumberParameters > ParameterThreshold) {
+ ActualNumberParameters > ParameterThreshold ||
+ !FI.NestingThresholders.empty()) {
diag(Func->getLocation(),
"function %0 exceeds recommended size/complexity thresholds")
<< Func;
@@ -138,6 +154,12 @@
DiagnosticIDs::Note)
<< ActualNumberParameters << ParameterThreshold;
}
+
+ for (const auto &CSPos : FI.NestingThresholders) {
+ diag(CSPos, "nesting level %0 starts here (threshold %1)",
+ DiagnosticIDs::Note)
+ << NestingThreshold + 1 << NestingThreshold;
+ }
}
} // namespace readability