[PATCH] D126578: [clang] Add tests for (const) weak variables

[Anders Waldenborg via Phabricator via cfe-commits]

wanders created this revision.
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This adds tests checking the behavior of const variables declared with
weak attribute.

Both checking that they can not be used in places where a constant
expression is required and that a dynamic initializer is emitted when
used as an initializer expression.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D126578

Files:
  clang/test/CodeGenCXX/weak-init.cpp
  clang/test/SemaCXX/weak-init.cpp


Index: clang/test/SemaCXX/weak-init.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/weak-init.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+
+extern const int W1 __attribute__ ((weak)) = 10; // expected-note {{declared here}}
+
+static_assert(W1 == 10, ""); // expected-error   {{static_assert expression is not an integral constant expression}}
+                             // expected-note at -1 {{initializer of weak variable 'W1' is not considered constant because it may be different at runtime}}
+
+
+extern const int W2 __attribute__ ((weak)) = 20;
+
+int S2[W2];  // expected-error {{variable length array declaration not allowed at file scope}}
+
+
+extern const int W3 __attribute__ ((weak)) = 30; // expected-note {{declared here}}
+
+constexpr int S3 = W3; // expected-error   {{constexpr variable 'S3' must be initialized by a constant expression}}
+                       // expected-note at -1 {{initializer of weak variable 'W3' is not considered constant because it may be different at runtime}}
Index: clang/test/CodeGenCXX/weak-init.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/weak-init.cpp
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
+
+extern const int W __attribute__ ((weak)) = 99;
+const int S = 77;
+
+// CHECK: @C1 = {{.*}} 77
+extern const int C1 = S;
+
+// CHECK: %0 = load {{.*}} @W
+// CHECK-NEXT: store {{.*}} %0, {{.*}} @C2
+extern const int C2 = W;


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