[clang] [BoundsSafety][Clang][Sema][AST] Introduce CThisExpr for C __counted_by attributes (PR #199241)

[Oliver Hunt via cfe-commits]

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@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -fsyntax-only -ast-dump %s | FileCheck %s
+
+// Verifying that CThisExpr generation works for sturct fields
+struct Packet {
+    int size;
+    int *data __attribute__((counted_by(size)));
+};
+
+// CHECK: RecordDecl {{.*}} struct Packet definition
+// CHECK: FieldDecl {{.*}} size 'int'
+// CHECK: FieldDecl {{.*}} data 'int * __counted_by(this->size)':'int *'
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ojhunt wrote:

dumb idea: in C say `{this}` or `"this"` maybe? some indicator that it's not a real keyword

https://github.com/llvm/llvm-project/pull/199241