r257357 - [Sema] Issue a warning for integer overflow in struct initializer

[Akira Hatanaka via cfe-commits]

Author: ahatanak
Date: Mon Jan 11 11:22:01 2016
New Revision: 257357

URL: http://llvm.org/viewvc/llvm-project?rev=257357&view=rev
Log:
[Sema] Issue a warning for integer overflow in struct initializer

Clang wasn't issuing a warning when compiling the following code:

struct s {
  unsigned x;
} s = {
  .x = 4 * 1024 * 1024 * 1024
};

rdar://problem/23399683

Differential Revision: http://reviews.llvm.org/D15097

Modified:
    cfe/trunk/lib/Sema/SemaChecking.cpp
    cfe/trunk/test/Sema/integer-overflow.c

Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=257357&r1=257356&r2=257357&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Mon Jan 11 11:22:01 2016
@@ -7853,6 +7853,10 @@ void Sema::CheckBoolLikeConversion(Expr
 void Sema::CheckForIntOverflow (Expr *E) {
   if (isa<BinaryOperator>(E->IgnoreParenCasts()))
     E->IgnoreParenCasts()->EvaluateForOverflow(Context);
+  else if (auto InitList = dyn_cast<InitListExpr>(E))
+    for (Expr *E : InitList->inits())
+      if (isa<BinaryOperator>(E->IgnoreParenCasts()))
+        E->IgnoreParenCasts()->EvaluateForOverflow(Context);
 }
 
 namespace {

Modified: cfe/trunk/test/Sema/integer-overflow.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/integer-overflow.c?rev=257357&r1=257356&r2=257357&view=diff
==============================================================================
--- cfe/trunk/test/Sema/integer-overflow.c (original)
+++ cfe/trunk/test/Sema/integer-overflow.c Mon Jan 11 11:22:01 2016
@@ -145,3 +145,11 @@ uint64_t check_integer_overflows(int i)
 // expected-warning at +1 2{{overflow in expression; result is 536870912 with type 'int'}}
   return ((4608 * 1024 * 1024) + ((uint64_t)(4608 * 1024 * 1024)));
 }
+
+struct s {
+  unsigned x;
+  unsigned y;
+} s = {
+  .y = 5,
+  .x = 4 * 1024 * 1024 * 1024  // expected-warning {{overflow in expression; result is 0 with type 'int'}}
+};