ilya updated this revision to Diff 235184.
ilya added a comment.
1. Refactor `CheckArrayAccess()` to take `AllowPastTheEnd` parameter to avoid a
false positive array out-of-bounds warning for `&(cond ? arr1[N] : arr2[N])`.
2. Use `IgnoreParenCasts()` instead of `IgnoreParenImpCasts()` in
`CheckArrayAccess()` to avoid false negatives when explicit cast is involved.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D71714/new/
https://reviews.llvm.org/D71714
Files:
clang/include/clang/Sema/Sema.h
clang/lib/Sema/SemaChecking.cpp
clang/test/Parser/cxx-ambig-decl-expr.cpp
clang/test/SemaCXX/array-bounds.cpp
Index: clang/test/SemaCXX/array-bounds.cpp
===================================================================
--- clang/test/SemaCXX/array-bounds.cpp
+++ clang/test/SemaCXX/array-bounds.cpp
@@ -27,7 +27,7 @@
};
void f1(int a[1]) {
- int val = a[3]; // no warning for function argumnet
+ int val = a[3]; // no warning for function argument
}
void f2(const int (&a)[2]) { // expected-note {{declared here}}
@@ -133,7 +133,7 @@
int test_sizeof_as_condition(int flag) {
int arr[2] = { 0, 0 }; // expected-note {{array 'arr' declared here}}
- if (flag)
+ if (flag)
return sizeof(char) != sizeof(char) ? arr[2] : arr[1];
return sizeof(char) == sizeof(char) ? arr[2] : arr[1]; // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
}
@@ -241,7 +241,7 @@
}
int test_pr11007_aux(const char * restrict, ...);
-
+
// Test checking with varargs.
void test_pr11007() {
double a[5]; // expected-note {{array 'a' declared here}}
@@ -309,3 +309,25 @@
foo<int>(); // expected-note 1{{in instantiation of function template specialization}}
};
}
+
+namespace PR44343 {
+ const unsigned int array[2] = {0, 1}; // expected-note 5{{array 'array' declared here}}
+
+ const int i1 = (const int)array[2]; // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+ const int i2 = static_cast<const int>(array[2]); // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+ const int &i3 = reinterpret_cast<const int&>(array[2]); // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+ unsigned int &i4 = const_cast<unsigned int&>(array[2]); // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+ int i5 = int(array[2]); // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+ const unsigned int *i6 = &(1 > 0 ? array[2] : array[1]); // no warning for one-past-end element's address retrieval
+
+ struct Base {
+ virtual ~Base();
+ };
+
+ struct Derived : Base {
+ };
+
+ Base baseArr[2]; // expected-note {{array 'baseArr' declared here}}
+ Derived *d1 = dynamic_cast<Derived *>(&baseArr[2]); // no warning for one-past-end element's address retrieval
+ Derived &d2 = dynamic_cast<Derived &>(baseArr[2]); // expected-warning {{array index 2 is past the end of the array (which contains 2 elements)}}
+}
Index: clang/test/Parser/cxx-ambig-decl-expr.cpp
===================================================================
--- clang/test/Parser/cxx-ambig-decl-expr.cpp
+++ clang/test/Parser/cxx-ambig-decl-expr.cpp
@@ -24,7 +24,7 @@
// This is array indexing not an array declarator because a comma expression
// is not syntactically a constant-expression.
- int(x[1,1]); // expected-warning 2{{unused}}
+ int(x[1,0]); // expected-warning 2{{unused}}
// This is array indexing not an array declaration because a braced-init-list
// is not syntactically a constant-expression.
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -13368,62 +13368,63 @@
<< ND->getDeclName());
}
-void Sema::CheckArrayAccess(const Expr *expr) {
- int AllowOnePastEnd = 0;
- while (expr) {
- expr = expr->IgnoreParenImpCasts();
- switch (expr->getStmtClass()) {
- case Stmt::ArraySubscriptExprClass: {
- const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
- CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE,
- AllowOnePastEnd > 0);
- expr = ASE->getBase();
- break;
- }
- case Stmt::MemberExprClass: {
- expr = cast<MemberExpr>(expr)->getBase();
- break;
- }
- case Stmt::OMPArraySectionExprClass: {
- const OMPArraySectionExpr *ASE = cast<OMPArraySectionExpr>(expr);
- if (ASE->getLowerBound())
- CheckArrayAccess(ASE->getBase(), ASE->getLowerBound(),
- /*ASE=*/nullptr, AllowOnePastEnd > 0);
- return;
- }
- case Stmt::UnaryOperatorClass: {
- // Only unwrap the * and & unary operators
- const UnaryOperator *UO = cast<UnaryOperator>(expr);
- expr = UO->getSubExpr();
- switch (UO->getOpcode()) {
- case UO_AddrOf:
- AllowOnePastEnd++;
- break;
- case UO_Deref:
- AllowOnePastEnd--;
- break;
- default:
- return;
- }
- break;
- }
- case Stmt::ConditionalOperatorClass: {
- const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
- if (const Expr *lhs = cond->getLHS())
- CheckArrayAccess(lhs);
- if (const Expr *rhs = cond->getRHS())
- CheckArrayAccess(rhs);
- return;
- }
- case Stmt::CXXOperatorCallExprClass: {
- const auto *OCE = cast<CXXOperatorCallExpr>(expr);
- for (const auto *Arg : OCE->arguments())
- CheckArrayAccess(Arg);
- return;
- }
- default:
- return;
+void Sema::CheckArrayAccess(const Expr *expr, int AllowOnePastEnd) {
+ if (!expr)
+ return;
+
+ expr = expr->IgnoreParenCasts();
+ switch (expr->getStmtClass()) {
+ case Stmt::ArraySubscriptExprClass: {
+ const ArraySubscriptExpr *ASE = cast<ArraySubscriptExpr>(expr);
+ CheckArrayAccess(ASE->getBase(), ASE->getIdx(), ASE, AllowOnePastEnd > 0);
+ CheckArrayAccess(ASE->getBase(), AllowOnePastEnd);
+ return;
+ }
+ case Stmt::MemberExprClass: {
+ expr = cast<MemberExpr>(expr)->getBase();
+ CheckArrayAccess(expr, AllowOnePastEnd);
+ return;
+ }
+ case Stmt::OMPArraySectionExprClass: {
+ const OMPArraySectionExpr *ASE = cast<OMPArraySectionExpr>(expr);
+ if (ASE->getLowerBound())
+ CheckArrayAccess(ASE->getBase(), ASE->getLowerBound(),
+ /*ASE=*/nullptr, AllowOnePastEnd > 0);
+ return;
+ }
+ case Stmt::UnaryOperatorClass: {
+ // Only unwrap the * and & unary operators
+ const UnaryOperator *UO = cast<UnaryOperator>(expr);
+ expr = UO->getSubExpr();
+ switch (UO->getOpcode()) {
+ case UO_AddrOf:
+ AllowOnePastEnd++;
+ break;
+ case UO_Deref:
+ AllowOnePastEnd--;
+ break;
+ default:
+ return;
}
+ CheckArrayAccess(expr, AllowOnePastEnd);
+ return;
+ }
+ case Stmt::ConditionalOperatorClass: {
+ const ConditionalOperator *cond = cast<ConditionalOperator>(expr);
+ if (const Expr *lhs = cond->getLHS())
+ CheckArrayAccess(lhs, AllowOnePastEnd);
+ if (const Expr *rhs = cond->getRHS())
+ CheckArrayAccess(rhs, AllowOnePastEnd);
+ return;
+ }
+ case Stmt::CXXOperatorCallExprClass: {
+ const auto *OCE = cast<CXXOperatorCallExpr>(expr);
+ for (const auto *Arg : OCE->arguments())
+ CheckArrayAccess(Arg);
+ return;
+ }
+ default:
+ return;
}
}
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -11390,7 +11390,7 @@
void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
const ArraySubscriptExpr *ASE=nullptr,
bool AllowOnePastEnd=true, bool IndexNegated=false);
- void CheckArrayAccess(const Expr *E);
+ void CheckArrayAccess(const Expr *E, int AllowOnePastEnd=0);
// Used to grab the relevant information from a FormatAttr and a
// FunctionDeclaration.
struct FormatStringInfo {
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