[analyzer] Add a CFG node for the allocator call in a C++ 'new' expression.

In an expression like "new (a, b) Foo(x, y)", two things happen:
- Memory is allocated by calling a function named 'operator new'.
- The memory is initialized using the constructor for 'Foo'.

Currently the analyzer only models the second event, though it has special
cases for both the default and placement forms of operator new. This patch
is the first step towards properly modeling both events: it changes the CFG
so that the above expression now generates the following elements.

1. a
2. b
3. (CFGNewAllocator)
4. x
5. y
6. Foo::Foo

The analyzer currently ignores the CFGNewAllocator element, but the next
step is to treat that as a call like any other.

The CFGNewAllocator element is not added to the CFG for analysis-based
warnings, since none of them take advantage of it yet.

llvm-svn: 199123

1 files changed, 78 insertions, 15 deletions

diff --git a/clang/test/Analysis/cfg.cpp b/clang/test/Analysis/cfg.cpp
index 9da220e8c32..40bc3138b66 100644
--- a/clang/test/Analysis/cfg.cpp
+++ b/clang/test/Analysis/cfg.cpp
@@ -110,13 +110,14 @@ public:
 // CHECK: [B2 (ENTRY)]
 // CHECK-NEXT:   Succs (1): B1
 // CHECK: [B1]
-// CHECK-NEXT:   1:  (CXXConstructExpr, class A)
-// CHECK-NEXT:   2: new A([B1.1])
-// CHECK-NEXT:   3: A *a = new A();
-// CHECK-NEXT:   4: a
-// CHECK-NEXT:   5: [B1.4] (ImplicitCastExpr, LValueToRValue, class A *)
-// CHECK-NEXT:   6: [B1.5]->~A() (Implicit destructor)
-// CHECK-NEXT:   7: delete [B1.5]
+// CHECK-NEXT:   1:  CFGNewAllocator(A *)
+// CHECK-NEXT:   2:  (CXXConstructExpr, class A)
+// CHECK-NEXT:   3: new A([B1.2])
+// CHECK-NEXT:   4: A *a = new A();
+// CHECK-NEXT:   5: a
+// CHECK-NEXT:   6: [B1.5] (ImplicitCastExpr, LValueToRValue, class A *)
+// CHECK-NEXT:   7: [B1.6]->~A() (Implicit destructor)
+// CHECK-NEXT:   8: delete [B1.6]
 // CHECK-NEXT:   Preds (1): B2
 // CHECK-NEXT:   Succs (1): B0
 // CHECK: [B0 (EXIT)]
@@ -130,13 +131,14 @@ void test_deletedtor() {
 // CHECK-NEXT:   Succs (1): B1
 // CHECK: [B1]
 // CHECK-NEXT:   1: 5
-// CHECK-NEXT:   2:  (CXXConstructExpr, class A)
-// CHECK-NEXT:   3: new A {{\[\[}}B1.1]]
-// CHECK-NEXT:   4: A *a = new A [5];
-// CHECK-NEXT:   5: a
-// CHECK-NEXT:   6: [B1.5] (ImplicitCastExpr, LValueToRValue, class A *)
-// CHECK-NEXT:   7: [B1.6]->~A() (Implicit destructor)
-// CHECK-NEXT:   8: delete [] [B1.6]
+// CHECK-NEXT:   2: CFGNewAllocator(A *)
+// CHECK-NEXT:   3:  (CXXConstructExpr, class A)
+// CHECK-NEXT:   4: new A {{\[\[}}B1.1]]
+// CHECK-NEXT:   5: A *a = new A [5];
+// CHECK-NEXT:   6: a
+// CHECK-NEXT:   7: [B1.6] (ImplicitCastExpr, LValueToRValue, class A *)
+// CHECK-NEXT:   8: [B1.7]->~A() (Implicit destructor)
+// CHECK-NEXT:   9: delete [] [B1.7]
 // CHECK-NEXT:   Preds (1): B2
 // CHECK-NEXT:   Succs (1): B0
 // CHECK: [B0 (EXIT)]
@@ -308,4 +310,65 @@ int test_enum_with_extension_default(enum MyEnum value) {
     default: x = 4; break;
   }
   return x;
-}
\ No newline at end of file
+}
+
+
+// CHECK:  [B1 (ENTRY)]
+// CHECK-NEXT:  Succs (1): B0
+// CHECK:  [B0 (EXIT)]
+// CHECK-NEXT:  Preds (1): B1
+// CHECK:  [B1 (ENTRY)]
+// CHECK-NEXT:  Succs (1): B0
+// CHECK:  [B0 (EXIT)]
+// CHECK-NEXT:  Preds (1): B1
+// CHECK:  [B2 (ENTRY)]
+// CHECK-NEXT:  Succs (1): B1
+// CHECK:  [B1]
+// CHECK-NEXT:  1: int buffer[16];
+// CHECK-NEXT:  2: buffer
+// CHECK-NEXT:  3: [B1.2] (ImplicitCastExpr, ArrayToPointerDecay, int *)
+// CHECK-NEXT:  4: [B1.3] (ImplicitCastExpr, BitCast, void *)
+// CHECK-NEXT:  5: CFGNewAllocator(MyClass *)
+// CHECK-NEXT:  6:  (CXXConstructExpr, class MyClass)
+// CHECK-NEXT:  7: new ([B1.4]) MyClass([B1.6])
+// CHECK-NEXT:  8: MyClass *obj = new (buffer) MyClass();
+// CHECK-NEXT:  Preds (1): B2
+// CHECK-NEXT:  Succs (1): B0
+// CHECK: [B0 (EXIT)]
+// CHECK-NEXT:  Preds (1): B1
+
+extern void* operator new (unsigned long sz, void* v);
+extern void* operator new[] (unsigned long sz, void* ptr);
+
+class MyClass {
+public:
+  MyClass() {}
+  ~MyClass() {}
+};
+
+void test_placement_new() {
+  int buffer[16];
+  MyClass* obj = new (buffer) MyClass();
+}
+
+// CHECK:  [B2 (ENTRY)]
+// CHECK-NEXT:  Succs (1): B1
+// CHECK: [B1]
+// CHECK-NEXT:  1: int buffer[16];
+// CHECK-NEXT:  2: buffer
+// CHECK-NEXT:  3: [B1.2] (ImplicitCastExpr, ArrayToPointerDecay, int *)
+// CHECK-NEXT:  4: [B1.3] (ImplicitCastExpr, BitCast, void *)
+// CHECK-NEXT:  5: 5
+// CHECK-NEXT:  6: CFGNewAllocator(MyClass *)
+// CHECK-NEXT:  7:  (CXXConstructExpr, class MyClass)
+// CHECK-NEXT:  8: new ([B1.4]) MyClass {{\[\[}}B1.5]]
+// CHECK-NEXT:  9: MyClass *obj = new (buffer) MyClass [5];
+// CHECK-NEXT:  Preds (1): B2
+// CHECK-NEXT:  Succs (1): B0
+// CHECK: [B0 (EXIT)]
+// CHECK-NEXT:  Preds (1): B1
+
+void test_placement_new_array() {
+  int buffer[16];
+  MyClass* obj = new (buffer) MyClass[5];
+}