10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
27 void RedundantStrcatCallsCheck::registerMatchers(MatchFinder* Finder) {
28 const auto CallToStrcat =
29 callExpr(callee(functionDecl(hasName(
"::absl::StrCat"))));
30 const auto CallToStrappend =
31 callExpr(callee(functionDecl(hasName(
"::absl::StrAppend"))));
34 const auto CallToEither = callExpr(
35 callee(functionDecl(hasAnyName(
"::absl::StrCat",
"::absl::StrAppend"))));
37 callExpr(CallToStrcat, unless(hasAncestor(CallToEither))).bind(
"StrCat"),
39 Finder->addMatcher(CallToStrappend.bind(
"StrAppend"),
this);
44 struct StrCatCheckResult {
49 void removeCallLeaveArgs(
const CallExpr *Call, StrCatCheckResult *CheckResult) {
50 if (Call->getNumArgs() == 0)
53 CheckResult->Hints.push_back(
54 FixItHint::CreateRemoval(CharSourceRange::getCharRange(
55 Call->getBeginLoc(), Call->getArg(0)->getBeginLoc())));
57 CheckResult->Hints.push_back(
58 FixItHint::CreateRemoval(CharSourceRange::getCharRange(
59 Call->getRParenLoc(), Call->getEndLoc().getLocWithOffset(1))));
62 const clang::CallExpr *processArgument(
const Expr *Arg,
63 const MatchFinder::MatchResult &Result,
64 StrCatCheckResult *CheckResult) {
65 const auto IsAlphanum = hasDeclaration(cxxMethodDecl(hasName(
"AlphaNum")));
66 static const auto*
const Strcat =
new auto(hasName(
"::absl::StrCat"));
67 const auto IsStrcat = cxxBindTemporaryExpr(
68 has(callExpr(callee(functionDecl(*Strcat))).bind(
"StrCat")));
69 if (
const auto *SubStrcatCall = selectFirst<const CallExpr>(
71 match(stmt(traverse(TK_AsIs,
72 anyOf(cxxConstructExpr(IsAlphanum,
73 hasArgument(0, IsStrcat)),
75 *Arg->IgnoreParenImpCasts(), *Result.Context))) {
76 removeCallLeaveArgs(SubStrcatCall, CheckResult);
82 StrCatCheckResult processCall(
const CallExpr *RootCall,
bool IsAppend,
83 const MatchFinder::MatchResult &Result) {
84 StrCatCheckResult CheckResult;
85 std::deque<const CallExpr*> CallsToProcess = {RootCall};
87 while (!CallsToProcess.empty()) {
88 ++CheckResult.NumCalls;
90 const CallExpr* CallExpr = CallsToProcess.front();
91 CallsToProcess.pop_front();
93 int StartArg = CallExpr == RootCall && IsAppend;
94 for (
const auto *Arg : CallExpr->arguments()) {
97 if (
const clang::CallExpr *Sub =
98 processArgument(Arg, Result, &CheckResult)) {
99 CallsToProcess.push_back(Sub);
110 const CallExpr* RootCall;
111 if ((RootCall = Result.Nodes.getNodeAs<CallExpr>(
"StrCat")))
113 else if ((RootCall = Result.Nodes.getNodeAs<CallExpr>(
"StrAppend")))
118 if (RootCall->getBeginLoc().isMacroID()) {
126 const StrCatCheckResult CheckResult = processCall(RootCall, IsAppend, Result);
127 if (CheckResult.NumCalls == 1) {
132 diag(RootCall->getBeginLoc(),
133 "multiple calls to 'absl::StrCat' can be flattened into a single call")
134 << CheckResult.Hints;