Perform array bounds checking in more situations and properly handle special

case situations with the unary operators & and *. Also extend the array bounds
checking to work with pointer arithmetic; the pointer arithemtic checking can
be turned on using -Warray-bounds-pointer-arithmetic.

The changes to where CheckArrayAccess gets called is based on some trial &
error and a bunch of digging through source code and gdb backtraces in order
to have the check performed under as many situations as possible (such as for
variable initializers, arguments to function calls, and within conditional in
addition to the simpler cases of the operands to binary and unary operator)
while not being called--and triggering warnings--more than once for a given
ArraySubscriptExpr.

llvm-svn: 136997

1 files changed, 18 insertions, 3 deletions

diff --git a/clang/test/SemaCXX/array-bounds.cpp b/clang/test/SemaCXX/array-bounds.cpp
index e8156320db4..2bbb4776ada 100644
--- a/clang/test/SemaCXX/array-bounds.cpp
+++ b/clang/test/SemaCXX/array-bounds.cpp
@@ -37,11 +37,16 @@ void test() {
   s2.a[3] = 0; // no warning for 0-sized array
 
   union {
-    short a[2]; // expected-note {{declared here}}
+    short a[2]; // expected-note 4 {{declared here}}
     char c[4];
   } u;
   u.a[3] = 1; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}}
   u.c[3] = 1; // no warning
+  short *p = &u.a[2]; // no warning
+  p = &u.a[3]; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}}
+  *(&u.a[2]) = 1; // expected-warning {{array index of '2' indexes past the end of an array (that contains 2 elements)}}
+  *(&u.a[3]) = 1; // expected-warning {{array index of '3' indexes past the end of an array (that contains 2 elements)}}
+  *(&u.c[3]) = 1; // no warning
 
   const int const_subscript = 3;
   int array[2]; // expected-note {{declared here}}
@@ -153,8 +158,7 @@ void test_switch() {
 enum enumA { enumA_A, enumA_B, enumA_C, enumA_D, enumA_E };
 enum enumB { enumB_X, enumB_Y, enumB_Z };
 static enum enumB myVal = enumB_X;
-void test_nested_switch()
-{
+void test_nested_switch() {
   switch (enumA_E) { // expected-warning {{no case matching constant}}
     switch (myVal) { // expected-warning {{enumeration values 'enumB_X' and 'enumB_Z' not handled in switch}}
       case enumB_Y: ;
@@ -199,3 +203,14 @@ namespace metaprogramming {
            B->c[3]; // expected-warning {{array index of '3' indexes past the end of an array (that contains 1 element)}}
   }
 }
+
+void bar(int x) {}
+int test_more() {
+  int foo[5]; // expected-note 5 {{array 'foo' declared here}}
+  bar(foo[5]); // expected-warning {{array index of '5' indexes past the end of an array (that contains 5 elements)}}
+  ++foo[5]; // expected-warning {{array index of '5' indexes past the end of an array (that contains 5 elements)}}
+  if (foo[6]) // expected-warning {{array index of '6' indexes past the end of an array (that contains 5 elements)}}
+    return --foo[6]; // expected-warning {{array index of '6' indexes past the end of an array (that contains 5 elements)}}
+  else
+    return foo[5]; // expected-warning {{array index of '5' indexes past the end of an array (that contains 5 elements)}}
+}