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[analyzer] Fix an assertion fail in CStringSyntaxChecker. 

Differential Revision: https://reviews.llvm.org/D29384

llvm-svn: 293874
This commit is contained in:
Gabor Horvath 2017-02-02 08:20:54 +00:00
parent 047a8be18a
commit 3b008536f3
2 changed files with 17 additions and 17 deletions
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32
clang/lib/StaticAnalyzer/Checkers/CStringSyntaxChecker.cpp
View File

@ -36,25 +36,24 @@ class WalkAST: public StmtVisitor<WalkAST> {
AnalysisDeclContext* AC;
/// Check if two expressions refer to the same declaration.
inline bool sameDecl(const Expr *A1, const Expr *A2) {
if (const DeclRefExpr *D1 = dyn_cast<DeclRefExpr>(A1->IgnoreParenCasts()))
if (const DeclRefExpr *D2 = dyn_cast<DeclRefExpr>(A2->IgnoreParenCasts()))
bool sameDecl(const Expr *A1, const Expr *A2) {
if (const auto *D1 = dyn_cast<DeclRefExpr>(A1->IgnoreParenCasts()))
if (const auto *D2 = dyn_cast<DeclRefExpr>(A2->IgnoreParenCasts()))
return D1->getDecl() == D2->getDecl();
return false;
}
/// Check if the expression E is a sizeof(WithArg).
inline bool isSizeof(const Expr *E, const Expr *WithArg) {
if (const UnaryExprOrTypeTraitExpr *UE =
dyn_cast<UnaryExprOrTypeTraitExpr>(E))
if (UE->getKind() == UETT_SizeOf)
bool isSizeof(const Expr *E, const Expr *WithArg) {
if (const auto *UE = dyn_cast<UnaryExprOrTypeTraitExpr>(E))
if (UE->getKind() == UETT_SizeOf && !UE->isArgumentType())
return sameDecl(UE->getArgumentExpr(), WithArg);
return false;
}
/// Check if the expression E is a strlen(WithArg).
inline bool isStrlen(const Expr *E, const Expr *WithArg) {
if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
bool isStrlen(const Expr *E, const Expr *WithArg) {
if (const auto *CE = dyn_cast<CallExpr>(E)) {
const FunctionDecl *FD = CE->getDirectCallee();
if (!FD)
return false;
@ -65,14 +64,14 @@ class WalkAST: public StmtVisitor<WalkAST> {
}
/// Check if the expression is an integer literal with value 1.
inline bool isOne(const Expr *E) {
if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
bool isOne(const Expr *E) {
if (const auto *IL = dyn_cast<IntegerLiteral>(E))
return (IL->getValue().isIntN(1));
return false;
}
inline StringRef getPrintableName(const Expr *E) {
if (const DeclRefExpr *D = dyn_cast<DeclRefExpr>(E->IgnoreParenCasts()))
StringRef getPrintableName(const Expr *E) {
if (const auto *D = dyn_cast<DeclRefExpr>(E->IgnoreParenCasts()))
return D->getDecl()->getName();
return StringRef();
}
@ -82,8 +81,8 @@ class WalkAST: public StmtVisitor<WalkAST> {
bool containsBadStrncatPattern(const CallExpr *CE);
public:
WalkAST(const CheckerBase *checker, BugReporter &br, AnalysisDeclContext *ac)
: Checker(checker), BR(br), AC(ac) {}
WalkAST(const CheckerBase *Checker, BugReporter &BR, AnalysisDeclContext *AC)
: Checker(Checker), BR(BR), AC(AC) {}
// Statement visitor methods.
void VisitChildren(Stmt *S);
@ -108,8 +107,7 @@ bool WalkAST::containsBadStrncatPattern(const CallExpr *CE) {
const Expr *LenArg = CE->getArg(2);
// Identify wrong size expressions, which are commonly used instead.
if (const BinaryOperator *BE =
dyn_cast<BinaryOperator>(LenArg->IgnoreParenCasts())) {
if (const auto *BE = dyn_cast<BinaryOperator>(LenArg->IgnoreParenCasts())) {
// - sizeof(dst) - strlen(dst)
if (BE->getOpcode() == BO_Sub) {
const Expr *L = BE->getLHS();

2
clang/test/Analysis/cstring-syntax.c
View File

@ -10,4 +10,6 @@ void testStrncat(const char *src) {
strncat(dest, "AAAAAAAAAAAAAAAAAAAAAAAAAAA", sizeof(dest)); // expected-warning {{Potential buffer overflow. Replace with}}
strncat(dest, "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", sizeof(dest) - strlen(dest)); // expected-warning {{Potential buffer overflow. Replace with}}
strncat(dest, src, sizeof(src)); // expected-warning {{Potential buffer overflow. Replace with}}
// Should not crash when sizeof has a type argument.
strncat(dest, "AAAAAAAAAAAAAAAAAAAAAAAAAAA", sizeof(char));
}