Treat aliases as definitions.

This fixes pr17639.

Before this patch clang would consider

void foo(void) __attribute((alias("__foo")));

a declaration. It now correctly handles it as a definition.

Initial patch by Alp Toker. I added support for variables.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193200 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 55 insertions, 0 deletions

diff --git a/test/Sema/alias-redefinition.c b/test/Sema/alias-redefinition.c
new file mode 100644
index 0000000000..6c6ebf8025
--- /dev/null
+++ b/test/Sema/alias-redefinition.c
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -verify %s
+
+void f0() {}
+void fun0(void) __attribute((alias("f0")));
+
+void f1() {}
+void fun1() {} // expected-note {{previous definition}}
+void fun1(void) __attribute((alias("f1"))); // expected-error {{redefinition of 'fun1'}}
+
+void f2() {}
+void fun2(void) __attribute((alias("f2"))); // expected-note {{previous definition}}
+void fun2() {} // expected-error {{redefinition of 'fun2'}}
+
+void f3() {}
+void fun3(void) __attribute((alias("f3"))); // expected-note {{previous definition}}
+void fun3(void) __attribute((alias("f3"))); // expected-error {{redefinition of 'fun3'}}
+
+void f4() {}
+void fun4(void) __attribute((alias("f4")));
+void fun4(void);
+
+// FIXME: We should produce a special case error for this.
+void f5() {}
+void __attribute((alias("f5"))) fun5(void) {} // expected-error {{redefinition of 'fun5'}} // expected-note {{previous definition}}
+
+int v1;
+int var1 __attribute((alias("v1"))); // expected-note {{previous definition}}
+int var1 __attribute((alias("v1"))); // expected-error {{redefinition of 'var1'}}
+
+int v2;
+int var2 = 2; // expected-note {{previous definition}}
+int var2 __attribute((alias("v2"))); // expected-error {{redefinition of 'var2'}}
+
+int v3;
+int var3 __attribute((alias("v3"))); // expected-note {{previous definition}}
+int var3 = 2; // expected-error {{redefinition of 'var3'}}
+
+int v4;
+int var4; // expected-note {{previous definition}}
+int var4 __attribute((alias("v4"))); // expected-error {{alias definition of 'var4' after tentative definition}}
+
+int v5;
+int var5 __attribute((alias("v5"))); // expected-note {{previous definition}}
+int var5; // expected-error {{tentative definition of 'var5' after alias definition}}
diff --git a/test/Sema/pragma-weak.c b/test/Sema/pragma-weak.c
new file mode 100644
index 0000000000..c14125eac9
--- /dev/null
+++ b/test/Sema/pragma-weak.c
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -verify %s
+
+void __both3(void);
+#pragma weak both3 = __both3 // expected-note {{previous definition}}
+void both3(void) __attribute((alias("__both3"))); // expected-error {{redefinition of 'both3'}}
+void __both3(void) {}
+
+void __a3(void) __attribute((noinline));
+#pragma weak a3 = __a3 // expected-note {{previous definition}}
+void a3(void) __attribute((alias("__a3"))); // expected-error {{redefinition of 'a3'}}
+void __a3(void) {}