diff options
| -rw-r--r-- | clang/lib/Sema/SemaChecking.cpp | 4 | ||||
| -rw-r--r-- | clang/test/SemaCXX/array-bounds.cpp | 23 |
2 files changed, 20 insertions, 7 deletions
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 28085ef6eab..81ae7b3afb0 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -3491,7 +3491,9 @@ static void CheckArrayAccess_Check(Sema &S, else if (size.getBitWidth() < index.getBitWidth()) size = size.sext(index.getBitWidth()); - if (index.slt(size)) + // Don't warn for valid indexes, or arrays of size 1 (which are often + // tail-allocated arrays that are emulating flexible arrays in C89 code). + if (index.slt(size) || size == 1) return; S.DiagRuntimeBehavior(E->getBase()->getLocStart(), BaseExpr, diff --git a/clang/test/SemaCXX/array-bounds.cpp b/clang/test/SemaCXX/array-bounds.cpp index 3bd6c35420d..044949200e0 100644 --- a/clang/test/SemaCXX/array-bounds.cpp +++ b/clang/test/SemaCXX/array-bounds.cpp @@ -24,8 +24,8 @@ void f1(int a[1]) { int val = a[3]; // no warning for function argumnet } -void f2(const int (&a)[1]) { // expected-note {{declared here}} - int val = a[3]; // expected-warning {{array index of '3' indexes past the end of an array (that contains 1 elements)}} +void f2(const int (&a)[2]) { // expected-note {{declared here}} + int val = a[3]; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}} } void test() { @@ -42,8 +42,8 @@ void test() { u.c[3] = 1; // no warning const int const_subscript = 3; - int array[1]; // expected-note {{declared here}} - array[const_subscript] = 0; // expected-warning {{array index of '3' indexes past the end of an array (that contains 1 elements)}} + int array[2]; // expected-note {{declared here}} + array[const_subscript] = 0; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}} int *ptr; ptr[3] = 0; // no warning for pointer references @@ -58,8 +58,8 @@ void test() { const char str2[] = "foo"; // expected-note {{declared here}} char c2 = str2[5]; // expected-warning {{array index of '5' indexes past the end of an array (that contains 4 elements)}} - int (*array_ptr)[1]; - (*array_ptr)[3] = 1; // expected-warning {{array index of '3' indexes past the end of an array (that contains 1 elements)}} + int (*array_ptr)[2]; + (*array_ptr)[3] = 1; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}} } template <int I> struct S { @@ -173,3 +173,14 @@ void test_all_enums_covered(enum Values v) { } x[2] = 0; // no-warning } + +namespace tailpad { + struct foo { + int x; + char c[1]; + }; + + char bar(struct foo *F) { + return F->c[3]; // no warning, foo could have tail padding allocated. + } +} |
