clang/test/AST/ByteCode/weak.cpp

   1 // RUN: %clang_cc1 -std=c++20 -fexperimental-new-constant-interpreter -verify=expected,both %s
   2 // RUN: %clang_cc1 -std=c++20 -verify=ref,both %s
   3
   4 [[gnu::weak]] extern int a;
   5 int ha[(bool)&a]; // both-warning {{variable length arrays in C++ are a Clang extension}} \
   6                   // both-error {{variable length array declaration not allowed at file scope}}
   7 int ha2[&a == nullptr]; // both-warning {{variable length arrays in C++ are a Clang extension}} \
   8                         // both-note {{comparison against address of weak declaration '&a' can only be performed at runtime}} \
   9                         // both-error {{variable length array declaration not allowed at file scope}}
  10
  11 extern const int W1 __attribute__((weak)) = 10; // both-note {{declared here}}
  12 static_assert(W1 == 10, ""); // both-error {{static assertion expression is not an integral constant expression}} \
  13                              // both-note {{initializer of weak variable 'W1' is not considered constant because it may be different at runtime}}
  14
  15 extern const int W2 __attribute__((weak)); // both-note {{declared here}}
  16 static_assert(W2 == 10, ""); // both-error {{static assertion expression is not an integral constant expression}} \
  17                              // both-note {{initializer of 'W2' is unknown}}