[PATCH] D52750: [Diagnostics] Check for integer overflow in array size expressions

[Dávid Bolvanský via Phabricator via cfe-commits]

xbolva00 created this revision.
xbolva00 added a reviewer: rsmith.
Herald added a subscriber: cfe-commits.

Fixes PR27439


Repository:
  rC Clang

https://reviews.llvm.org/D52750

Files:
  lib/Sema/SemaType.cpp
  test/Sema/integer-overflow.c


Index: test/Sema/integer-overflow.c
===================================================================
--- test/Sema/integer-overflow.c
+++ test/Sema/integer-overflow.c
@@ -172,6 +172,9 @@
 // expected-warning@+1 {{overflow in expression; result is 536870912 with type 
'int'}}
   (void)f2(0, f0(4608 * 1024 * 1024));
 }
+void check_integer_overflows_in_array_size() {
+  int arr[4608 * 1024 * 1024]; // expected-warning {{overflow in expression; 
result is 536870912 with type 'int'}}
+}
 
 struct s {
   unsigned x;
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -2082,7 +2082,7 @@
 QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
                               Expr *ArraySize, unsigned Quals,
                               SourceRange Brackets, DeclarationName Entity) {
-
+  ArraySize->EvaluateForOverflow(Context);
   SourceLocation Loc = Brackets.getBegin();
   if (getLangOpts().CPlusPlus) {
     // C++ [dcl.array]p1:



Index: test/Sema/integer-overflow.c
===================================================================
--- test/Sema/integer-overflow.c
+++ test/Sema/integer-overflow.c
@@ -172,6 +172,9 @@
 // expected-warning@+1 {{overflow in expression; result is 536870912 with type 'int'}}
   (void)f2(0, f0(4608 * 1024 * 1024));
 }
+void check_integer_overflows_in_array_size() {
+  int arr[4608 * 1024 * 1024]; // expected-warning {{overflow in expression; result is 536870912 with type 'int'}}
+}
 
 struct s {
   unsigned x;
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -2082,7 +2082,7 @@
 QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
                               Expr *ArraySize, unsigned Quals,
                               SourceRange Brackets, DeclarationName Entity) {
-
+  ArraySize->EvaluateForOverflow(Context);
   SourceLocation Loc = Brackets.getBegin();
   if (getLangOpts().CPlusPlus) {
     // C++ [dcl.array]p1:

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