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//===--- ArgumentCommentCheck.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 "ArgumentCommentCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/Token.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace misc {
ArgumentCommentCheck::ArgumentCommentCheck(StringRef Name,
ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
IdentRE("^(/\\* *)([_A-Za-z][_A-Za-z0-9]*)( *= *\\*/)$") {}
void ArgumentCommentCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
callExpr(unless(cxxOperatorCallExpr()),
// NewCallback's arguments relate to the pointed function, don't
// check them against NewCallback's parameter names.
// FIXME: Make this configurable.
unless(hasDeclaration(functionDecl(anyOf(
hasName("NewCallback"), hasName("NewPermanentCallback"))))))
.bind("expr"),
this);
Finder->addMatcher(cxxConstructExpr().bind("expr"), this);
}
static std::vector<std::pair<SourceLocation, StringRef>>
getCommentsInRange(ASTContext *Ctx, CharSourceRange Range) {
std::vector<std::pair<SourceLocation, StringRef>> Comments;
auto &SM = Ctx->getSourceManager();
std::pair<FileID, unsigned> BeginLoc = SM.getDecomposedLoc(Range.getBegin()),
EndLoc = SM.getDecomposedLoc(Range.getEnd());
if (BeginLoc.first != EndLoc.first)
return Comments;
bool Invalid = false;
StringRef Buffer = SM.getBufferData(BeginLoc.first, &Invalid);
if (Invalid)
return Comments;
const char *StrData = Buffer.data() + BeginLoc.second;
Lexer TheLexer(SM.getLocForStartOfFile(BeginLoc.first), Ctx->getLangOpts(),
Buffer.begin(), StrData, Buffer.end());
TheLexer.SetCommentRetentionState(true);
while (true) {
Token Tok;
if (TheLexer.LexFromRawLexer(Tok))
break;
if (Tok.getLocation() == Range.getEnd() || Tok.getKind() == tok::eof)
break;
if (Tok.getKind() == tok::comment) {
std::pair<FileID, unsigned> CommentLoc =
SM.getDecomposedLoc(Tok.getLocation());
assert(CommentLoc.first == BeginLoc.first);
Comments.emplace_back(
Tok.getLocation(),
StringRef(Buffer.begin() + CommentLoc.second, Tok.getLength()));
}
}
return Comments;
}
bool
ArgumentCommentCheck::isLikelyTypo(llvm::ArrayRef<ParmVarDecl *> Params,
StringRef ArgName, unsigned ArgIndex) {
std::string ArgNameLower = ArgName.lower();
unsigned UpperBound = (ArgName.size() + 2) / 3 + 1;
unsigned ThisED = StringRef(ArgNameLower).edit_distance(
Params[ArgIndex]->getIdentifier()->getName().lower(),
/*AllowReplacements=*/true, UpperBound);
if (ThisED >= UpperBound)
return false;
for (unsigned I = 0, E = Params.size(); I != E; ++I) {
if (I == ArgIndex)
continue;
IdentifierInfo *II = Params[I]->getIdentifier();
if (!II)
continue;
const unsigned Threshold = 2;
// Other parameters must be an edit distance at least Threshold more away
// from this parameter. This gives us greater confidence that this is a typo
// of this parameter and not one with a similar name.
unsigned OtherED = StringRef(ArgNameLower).edit_distance(
II->getName().lower(),
/*AllowReplacements=*/true, ThisED + Threshold);
if (OtherED < ThisED + Threshold)
return false;
}
return true;
}
void ArgumentCommentCheck::checkCallArgs(ASTContext *Ctx,
const FunctionDecl *Callee,
SourceLocation ArgBeginLoc,
llvm::ArrayRef<const Expr *> Args) {
Callee = Callee->getFirstDecl();
for (unsigned i = 0,
e = std::min<unsigned>(Args.size(), Callee->getNumParams());
i != e; ++i) {
const ParmVarDecl *PVD = Callee->getParamDecl(i);
IdentifierInfo *II = PVD->getIdentifier();
if (!II)
continue;
if (auto Template = Callee->getTemplateInstantiationPattern()) {
// Don't warn on arguments for parameters instantiated from template
// parameter packs. If we find more arguments than the template definition
// has, it also means that they correspond to a parameter pack.
if (Template->getNumParams() <= i ||
Template->getParamDecl(i)->isParameterPack()) {
continue;
}
}
CharSourceRange BeforeArgument = CharSourceRange::getCharRange(
i == 0 ? ArgBeginLoc : Args[i - 1]->getLocEnd(),
Args[i]->getLocStart());
BeforeArgument = Lexer::makeFileCharRange(
BeforeArgument, Ctx->getSourceManager(), Ctx->getLangOpts());
for (auto Comment : getCommentsInRange(Ctx, BeforeArgument)) {
llvm::SmallVector<StringRef, 2> Matches;
if (IdentRE.match(Comment.second, &Matches)) {
if (Matches[2] != II->getName()) {
{
DiagnosticBuilder Diag =
diag(Comment.first, "argument name '%0' in comment does not "
"match parameter name %1")
<< Matches[2] << II;
if (isLikelyTypo(Callee->parameters(), Matches[2], i)) {
Diag << FixItHint::CreateReplacement(
Comment.first,
(Matches[1] + II->getName() + Matches[3]).str());
}
}
diag(PVD->getLocation(), "%0 declared here", DiagnosticIDs::Note)
<< II;
}
}
}
}
}
void ArgumentCommentCheck::check(const MatchFinder::MatchResult &Result) {
const Expr *E = Result.Nodes.getNodeAs<Expr>("expr");
if (auto Call = dyn_cast<CallExpr>(E)) {
const FunctionDecl *Callee = Call->getDirectCallee();
if (!Callee)
return;
checkCallArgs(Result.Context, Callee, Call->getCallee()->getLocEnd(),
llvm::makeArrayRef(Call->getArgs(), Call->getNumArgs()));
} else {
auto Construct = cast<CXXConstructExpr>(E);
checkCallArgs(
Result.Context, Construct->getConstructor(),
Construct->getParenOrBraceRange().getBegin(),
llvm::makeArrayRef(Construct->getArgs(), Construct->getNumArgs()));
}
}
} // namespace misc
} // namespace tidy
} // namespace clang
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