nlewycky created this revision.
Make the integer overflow evaluator continue into expressions with non-literal
types, notably void.
In passing it fixes a crash attempting to codegen:
struct A { char x; };
struct B : virtual A {};
A = ((A&)*(B*)0);
which we nearly have a test for except that it casted to void and therefore was
ignored instead of being evaluated. The existing test
(test/SemaCXX/cstyle-cast.cpp) is sufficient to cover this case now that we
don't stop at a void cast.
https://reviews.llvm.org/D32675
Files:
lib/AST/ExprConstant.cpp
test/Sema/integer-overflow.c
Index: test/Sema/integer-overflow.c
===
--- test/Sema/integer-overflow.c
+++ test/Sema/integer-overflow.c
@@ -149,16 +149,16 @@
// expected-warning@+2 {{overflow in expression; result is 536870912 with type
'int'}}
uint64_t *b;
- uint64_t b2 = b[4608 * 1024 * 1024] + 1;
+ (void)b[4608 * 1024 * 1024];
// expected-warning@+1 2{{overflow in expression; result is 536870912 with
type 'int'}}
- int j1 = i ? (4608 * 1024 * 1024) : (4608 * 1024 * 1024);
+ (void)(i ? (4608 * 1024 * 1024) : (4608 * 1024 * 1024));
// expected-warning@+1 {{overflow in expression; result is 536870912 with type
'int'}}
- int j2 = -(4608 * 1024 * 1024);
+ (void)(-(4608 * 1024 * 1024));
// expected-warning@+1 {{overflow in expression; result is 536870912 with type
'int'}}
- uint64_t j3 = b[4608 * 1024 * 1024];
+ (void)b[4608 * 1024 * 1024];
// expected-warning@+1 2{{overflow in expression; result is 536870912 with
type 'int'}}
return ((4608 * 1024 * 1024) + ((uint64_t)(4608 * 1024 * 1024)));
Index: lib/AST/ExprConstant.cpp
===
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -2169,6 +2169,9 @@
if (!Base->isVirtual())
return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
+ if (!Obj.checkNullPointer(Info, E, CSK_Base))
+return false;
+
SubobjectDesignator = Obj.Designator;
if (D.Invalid)
return false;
@@ -9913,8 +9916,11 @@
if (E->getType().isNull())
return false;
- if (!CheckLiteralType(Info, E))
+ if (!CheckLiteralType(Info, E)) {
+if (Info.noteFailure())
+ EvaluateIgnoredValue(Info, E);
return false;
+ }
if (!::Evaluate(Result, Info, E))
return false;
Index: test/Sema/integer-overflow.c
===
--- test/Sema/integer-overflow.c
+++ test/Sema/integer-overflow.c
@@ -149,16 +149,16 @@
// expected-warning@+2 {{overflow in expression; result is 536870912 with type 'int'}}
uint64_t *b;
- uint64_t b2 = b[4608 * 1024 * 1024] + 1;
+ (void)b[4608 * 1024 * 1024];
// expected-warning@+1 2{{overflow in expression; result is 536870912 with type 'int'}}
- int j1 = i ? (4608 * 1024 * 1024) : (4608 * 1024 * 1024);
+ (void)(i ? (4608 * 1024 * 1024) : (4608 * 1024 * 1024));
// expected-warning@+1 {{overflow in expression; result is 536870912 with type 'int'}}
- int j2 = -(4608 * 1024 * 1024);
+ (void)(-(4608 * 1024 * 1024));
// expected-warning@+1 {{overflow in expression; result is 536870912 with type 'int'}}
- uint64_t j3 = b[4608 * 1024 * 1024];
+ (void)b[4608 * 1024 * 1024];
// expected-warning@+1 2{{overflow in expression; result is 536870912 with type 'int'}}
return ((4608 * 1024 * 1024) + ((uint64_t)(4608 * 1024 * 1024)));
Index: lib/AST/ExprConstant.cpp
===
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -2169,6 +2169,9 @@
if (!Base->isVirtual())
return HandleLValueDirectBase(Info, E, Obj, DerivedDecl, BaseDecl);
+ if (!Obj.checkNullPointer(Info, E, CSK_Base))
+return false;
+
SubobjectDesignator = Obj.Designator;
if (D.Invalid)
return false;
@@ -9913,8 +9916,11 @@
if (E->getType().isNull())
return false;
- if (!CheckLiteralType(Info, E))
+ if (!CheckLiteralType(Info, E)) {
+if (Info.noteFailure())
+ EvaluateIgnoredValue(Info, E);
return false;
+ }
if (!::Evaluate(Result, Info, E))
return false;
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