[Sema] Detecting more array index out of bounds

[danielmarjamaki]

Summary

Diagnose array index out of bounds when there is overloaded C++ operators also.

[aaron.ballman]

A few minor nits that can be resolved when you commit, but aside from those, LGTM.

lib/Sema/SemaChecking.cpp

10613 ↗

(On Diff #89183)

You can use const auto * here.

10614 ↗

(On Diff #89183)

const auto * instead of just auto.

cfe/trunk/lib/Sema/SemaChecking.cpp

switch (expr->getStmtClass()) {
       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;
     }
   }
 }
 
 //===--- CHECK: Objective-C retain cycles ----------------------------------//
 

cfe/trunk/test/SemaCXX/array-bounds.cpp

-// RUN: %clang_cc1 -verify %s
+// RUN: %clang_cc1 -verify -std=c++11 %s
 
 int foo() {
   int x[2]; // expected-note 4 {{array 'x' declared here}}
   int y[2]; // expected-note 2 {{array 'y' declared here}}
   int z[1]; // expected-note {{array 'z' declared here}}
   int w[1][1]; // expected-note {{array 'w' declared here}}
   int v[1][1][1]; // expected-note {{array 'v' declared here}}
   int *p = &y[2]; // no-warning
void test_pr11007() {
   test_pr11007_aux("foo", a[1000]); // expected-warning {{array index 1000 is past the end of the array}}
 }
 
 void test_rdar10916006(void)
 {
   int a[128]; // expected-note {{array 'a' declared here}}
   a[(unsigned char)'\xA1'] = 1; // expected-warning {{array index 161 is past the end of the array}}
 }
+
+struct P {
+  int a;
+  int b;
+};
+
+void test_struct_array_index() {
+  struct P p[10]; // expected-note {{array 'p' declared here}}
+  p[11] = {0, 1}; // expected-warning {{array index 11 is past the end of the array (which contains 10 elements)}}
+}
+
+int operator+(const struct P &s1, const struct P &s2);
+int test_operator_overload_struct_array_index() {
+  struct P x[10] = {0}; // expected-note {{array 'x' declared here}}
+  return x[1] + x[11]; // expected-warning {{array index 11 is past the end of the array (which contains 10 elements)}}
+}