llvm-project/clang-tools-extra/clang-tidy/readability/FunctionSizeCheck.cpp

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//===--- FunctionSize.cpp - clang-tidy ------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "FunctionSizeCheck.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace readability {
FunctionSizeCheck::FunctionSizeCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
LineThreshold(Options.get("LineThreshold", -1U)),
StatementThreshold(Options.get("StatementThreshold", 800U)),
BranchThreshold(Options.get("BranchThreshold", -1U)) {}
void FunctionSizeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "LineThreshold", LineThreshold);
Options.store(Opts, "StatementThreshold", StatementThreshold);
Options.store(Opts, "BranchThreshold", BranchThreshold);
}
void FunctionSizeCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
functionDecl(
unless(isInstantiated()),
forEachDescendant(
stmt(unless(compoundStmt()),
hasParent(stmt(anyOf(compoundStmt(), ifStmt(),
anyOf(whileStmt(), doStmt(),
cxxForRangeStmt(), forStmt())))))
.bind("stmt"))).bind("func"),
this);
}
void FunctionSizeCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
FunctionInfo &FI = FunctionInfos[Func];
// Count the lines including whitespace and comments. Really simple.
if (!FI.Lines) {
if (const Stmt *Body = Func->getBody()) {
SourceManager *SM = Result.SourceManager;
if (SM->isWrittenInSameFile(Body->getLocStart(), Body->getLocEnd())) {
FI.Lines = SM->getSpellingLineNumber(Body->getLocEnd()) -
SM->getSpellingLineNumber(Body->getLocStart());
}
}
}
const auto *Statement = Result.Nodes.getNodeAs<Stmt>("stmt");
++FI.Statements;
// TODO: switch cases, gotos
if (isa<IfStmt>(Statement) || isa<WhileStmt>(Statement) ||
isa<ForStmt>(Statement) || isa<SwitchStmt>(Statement) ||
isa<DoStmt>(Statement) || isa<CXXForRangeStmt>(Statement))
++FI.Branches;
}
void FunctionSizeCheck::onEndOfTranslationUnit() {
// If we're above the limit emit a warning.
for (const auto &P : FunctionInfos) {
const FunctionInfo &FI = P.second;
if (FI.Lines > LineThreshold || FI.Statements > StatementThreshold ||
FI.Branches > BranchThreshold) {
diag(P.first->getLocation(),
"function '%0' exceeds recommended size/complexity thresholds")
<< P.first->getNameAsString();
}
if (FI.Lines > LineThreshold) {
diag(P.first->getLocation(),
"%0 lines including whitespace and comments (threshold %1)",
DiagnosticIDs::Note)
<< FI.Lines << LineThreshold;
}
if (FI.Statements > StatementThreshold) {
diag(P.first->getLocation(), "%0 statements (threshold %1)",
DiagnosticIDs::Note)
<< FI.Statements << StatementThreshold;
}
if (FI.Branches > BranchThreshold) {
diag(P.first->getLocation(), "%0 branches (threshold %1)",
DiagnosticIDs::Note)
<< FI.Branches << BranchThreshold;
}
}
FunctionInfos.clear();
}
} // namespace readability
} // namespace tidy
} // namespace clang