alexey.knyshev created this revision.
alexey.knyshev added a project: clang.
Herald added subscribers: cfe-commits, mgorny.
Implementation of checker "different.LabelInsideSwitch" from potential checkers
list (https://clang-analyzer.llvm.org/potential_checkers.html#different)
Repository:
rC Clang
https://reviews.llvm.org/D40715
Files:
include/clang/StaticAnalyzer/Checkers/Checkers.td
lib/StaticAnalyzer/Checkers/CMakeLists.txt
lib/StaticAnalyzer/Checkers/LabelInsideSwitchChecker.cpp
test/Analysis/label-inside-switch.c
Index: test/Analysis/label-inside-switch.c
===================================================================
--- test/Analysis/label-inside-switch.c
+++ test/Analysis/label-inside-switch.c
@@ -0,0 +1,57 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core.LabelInsideSwitch -w -verify %s
+
+int caseAnddefaultMissprint(unsigned count) {
+ int res = 0;
+ switch(count) {
+ case 1:
+ res = 1;
+ break;
+ cas: // expected-warning {{label inside switch (did you mean 'case'?)}}
+ case 2:
+ res = 5;
+ break;
+ case 3:
+ exit(1);
+ defaul: // expected-warning {{label inside switch (did you mean 'default'?)}}
+ return -1;
+ }
+
+ return res;
+}
+
+int nestedSwitch(unsigned x, unsigned y) {
+ int res = 0;
+ switch (x) {
+ case 1:
+ res = 1;
+ break;
+ case 2:
+ res = 5;
+ break;
+ case 3:
+ switch(y) {
+ case 1:
+ case 2:
+ case 4:
+ res = x * y;
+ break;
+ defaul:; // expected-warning {{label inside switch (did you mean 'default'?)}}
+ }
+ break;
+ default:;
+ }
+
+ return res;
+}
+
+int arbitaryLabelInSwitch(int arg) {
+ switch (arg) {
+ case 1:
+ case 2:
+ label: // expected-warning {{label inside switch}}
+ case 3:
+ break;
+ }
+
+ return 0;
+}
Index: lib/StaticAnalyzer/Checkers/LabelInsideSwitchChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/LabelInsideSwitchChecker.cpp
+++ lib/StaticAnalyzer/Checkers/LabelInsideSwitchChecker.cpp
@@ -0,0 +1,121 @@
+#include "clang/AST/StmtVisitor.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/CommonBugCategories.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+ class LabelInsideSwitchChecker : public Checker< check::ASTCodeBody > {
+ public:
+ void checkASTCodeBody(const Decl *D, AnalysisManager &mgr, BugReporter &BR) const;
+ };
+
+ static std::pair<StringRef, bool> Suggest(const StringRef &Str, StringRef Exp);
+ static std::pair<StringRef, bool> SuggestTypoFix(const StringRef &Str) {
+ const auto S = Suggest(Str, "default");
+ if (S.second)
+ return S;
+
+ return Suggest(Str, "case");
+ }
+
+ class WalkAST : public ConstStmtVisitor<WalkAST, void, bool> {
+ const CheckerBase *Checker;
+ BugReporter &BR;
+ AnalysisDeclContext *AC;
+
+ public:
+ WalkAST(const CheckerBase *Checker, BugReporter &BR, AnalysisDeclContext *AC)
+ : Checker(Checker), BR(BR), AC(AC) {}
+
+ // Statement visitor methods.
+ void VisitChildren(const Stmt *S, bool InSwitch) {
+ for (const Stmt *Child : S->children())
+ if (Child)
+ Visit(Child, InSwitch);
+ }
+
+ void VisitStmt(const Stmt *S, bool InSwitch) {
+ if (!InSwitch && isa<SwitchStmt>(S)) {
+ InSwitch = true;
+ } else if (InSwitch && isa<LabelStmt>(S)) {
+ const LabelStmt *L = cast<LabelStmt>(S);
+ const auto Sug = SuggestTypoFix(L->getName());
+
+ SmallString<256> SBuf;
+ llvm::raw_svector_ostream OS(SBuf);
+ OS << "label inside switch";
+ if (Sug.second) {
+ OS << " (did you mean '" << Sug.first << "'?)";
+ }
+
+ PathDiagnosticLocation Loc =
+ PathDiagnosticLocation::createBegin(S, BR.getSourceManager(), AC);
+ SourceRange Sr[1];
+ Sr[0] = S->getSourceRange();
+ BR.EmitBasicReport(AC->getDecl(), Checker, "Labeled statement inside switch",
+ categories::LogicError, OS.str(), Loc, Sr);
+ }
+ VisitChildren(S, InSwitch);
+ }
+ };
+
+ std::pair<StringRef, bool> Suggest(const StringRef &Str, StringRef Exp) {
+ const size_t StrSize = Str.size();
+ const size_t ExpSize = Exp.size();
+
+ assert(StrSize);
+ assert(ExpSize);
+
+ size_t SizeDelta = 0;
+ size_t MinSize = StrSize;
+
+ if (StrSize < ExpSize) {
+ SizeDelta = ExpSize - StrSize;
+ } else if (StrSize > ExpSize) {
+ SizeDelta = StrSize - ExpSize;
+ MinSize = ExpSize;
+ }
+
+ // We only accept size delta <= 1
+ if (SizeDelta > 1)
+ return std::make_pair("", false);
+
+ size_t SameSymCount = 0;
+ for (size_t i = 0; i < MinSize; i++)
+ if (Str[i] == Exp[i])
+ SameSymCount++;
+
+ if (SameSymCount > 0 && SameSymCount - SizeDelta >= ExpSize / 2)
+ return std::make_pair(Exp, true);
+
+ // Str & Exp have the same size. No sence to check from back to front
+ if (SizeDelta == 0)
+ return std::make_pair("", false);
+
+ SameSymCount = 0;
+ for (size_t i = StrSize, j = ExpSize; i > 0 && j > 0; i--, j--)
+ if (Str[i - 1] == Exp[j - 1])
+ SameSymCount++;
+
+ if (SameSymCount > 0 && SameSymCount - SizeDelta >= ExpSize / 2)
+ return std::make_pair(Exp, true);
+
+ return std::make_pair("", false);
+ }
+} // end anonymous namespace
+
+void LabelInsideSwitchChecker::checkASTCodeBody(const Decl *D, AnalysisManager &mgr, BugReporter &BR) const {
+ WalkAST walker(this, BR, mgr.getAnalysisDeclContext(D));
+ walker.Visit(D->getBody(), /*InSwitch=*/ false);
+}
+
+namespace clang {
+ namespace ento {
+ void registerLabelInsideSwitchChecker(CheckerManager &mgr) {
+ mgr.registerChecker<LabelInsideSwitchChecker>();
+ }
+ } // end ento namespace
+} // end clang namespace
Index: lib/StaticAnalyzer/Checkers/CMakeLists.txt
===================================================================
--- lib/StaticAnalyzer/Checkers/CMakeLists.txt
+++ lib/StaticAnalyzer/Checkers/CMakeLists.txt
@@ -43,6 +43,7 @@
IteratorChecker.cpp
IvarInvalidationChecker.cpp
LLVMConventionsChecker.cpp
+ LabelInsideSwitchChecker.cpp
LocalizationChecker.cpp
MacOSKeychainAPIChecker.cpp
MacOSXAPIChecker.cpp
Index: include/clang/StaticAnalyzer/Checkers/Checkers.td
===================================================================
--- include/clang/StaticAnalyzer/Checkers/Checkers.td
+++ include/clang/StaticAnalyzer/Checkers/Checkers.td
@@ -160,6 +160,10 @@
HelpText<"Warn about unintended use of identical expressions in operators">,
DescFile<"IdenticalExprChecker.cpp">;
+def LabelInsideSwitchChecker : Checker<"LabelInsideSwitch">,
+ HelpText<"Warn about labeled statements inside switch">,
+ DescFile<"LabelInsideSwitchChecker.cpp">;
+
def FixedAddressChecker : Checker<"FixedAddr">,
HelpText<"Check for assignment of a fixed address to a pointer">,
DescFile<"FixedAddressChecker.cpp">;
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