PR3679: add #pragma weak test file

llvm-svn: 78016

clang/test/Sema/pragma-weak.c

@@ -0,0 +1,158 @@
+// RUN: clang-cc -emit-llvm -o %t %s &&
+
+#pragma weak weakvar
+int weakvar;
+// RUN: grep '@weakvar = weak global' %t | count 1 &&
+
+#pragma weak weakdef
+void weakdef(void) {}
+// RUN: grep 'define weak void @weakdef() nounwind {' %t | count 1 &&
+
+#pragma weak param // expected-warning {{weak identifier 'param' never declared}}
+#pragma weak correct_linkage
+void f(int param) {
+  int correct_linkage;
+}
+int correct_linkage;
+// RUN: grep '@correct_linkage = weak global' %t | count 1 &&
+
+#pragma weak weakvar_alias = __weakvar_alias
+int __weakvar_alias;
+// RUN: grep '@__weakvar_alias = common global' %t | count 1 &&
+// RUN: grep '@weakvar_alias = alias weak i32\* @__weakvar_alias' %t | count 1 &&
+//@weakvar_alias = alias weak i32* @__weakvar_alias
+
+#pragma weak foo = __foo
+void __foo(void) {}
+// RUN: grep '@foo = alias weak void ()\* @__foo\>' %t | count 1 &&
+// RUN: grep 'define void @__foo() nounwind {' %t | count 1 &&
+
+
+void __foo2(void) {}
+#pragma weak foo2 = __foo2
+// RUN: grep '@foo2 = alias weak void ()\* @__foo2\>' %t | count 1 &&
+// RUN: grep 'define void @__foo2() nounwind {' %t | count 1 &&
+
+
+///// test errors
+
+#pragma weak unused // expected-warning {{weak identifier 'unused' never declared}}
+#pragma weak unused_alias = __unused_alias  // expected-warning {{weak identifier '__unused_alias' never declared}}
+
+#pragma weak td // expected-warning {{weak identifier 'td' never declared}}
+typedef int td;
+
+#pragma weak td2 = __td2 // expected-warning {{weak identifier '__td2' never declared}}
+typedef int __td2;
+
+
+///// test weird cases
+
+// test repeats
+
+#pragma weak stutter = __stutter
+#pragma weak stutter = __stutter
+void __stutter(void) {}
+// RUN: grep '@stutter = alias weak void ()\* @__stutter\>' %t | count 1 &&
+// RUN: grep 'define void @__stutter() nounwind {' %t | count 1 &&
+
+void __stutter2(void) {}
+#pragma weak stutter2 = __stutter2
+#pragma weak stutter2 = __stutter2
+// RUN: grep '@stutter2 = alias weak void ()\* @__stutter2\>' %t | count 1 &&
+// RUN: grep 'define void @__stutter2() nounwind {' %t | count 1 &&
+
+
+// test decl/pragma weak order
+
+void __declfirst(void);
+#pragma weak declfirst = __declfirst
+void __declfirst(void) {}
+// RUN: grep '@declfirst = alias weak void ()\* @__declfirst\>' %t | count 1 &&
+// RUN: grep 'define void @__declfirst() nounwind {' %t | count 1 &&
+
+void __declfirstattr(void) __attribute((noinline));
+#pragma weak declfirstattr = __declfirstattr
+void __declfirstattr(void) {}
+// RUN: grep '@declfirstattr = alias weak void ()\* @__declfirstattr\>' %t | count 1 &&
+// RUN: grep 'define void @__declfirstattr() nounwind noinline {' %t | count 1 &&
+
+//// test that other attributes are preserved
+
+//// ensure that pragma weak/__attribute((weak)) play nice
+
+void mix(void);
+#pragma weak mix
+__attribute((weak)) void mix(void) { }
+// RUN: grep 'define weak void @mix() nounwind {' %t | count 1 &&
+
+// ensure following __attributes are preserved and that only a single
+// alias is generated
+#pragma weak mix2 = __mix2
+void __mix2(void) __attribute((noinline));
+void __mix2(void) __attribute((noinline));
+void __mix2(void) {}
+// RUN: grep '@mix2 = alias weak void ()\* @__mix2\>' %t | count 1 &&
+// RUN: grep 'define void @__mix2() nounwind noinline {' %t | count 1 &&
+
+////////////// test #pragma weak/__attribute combinations
+
+// if the SAME ALIAS is already declared then it overrides #pragma weak
+// resulting in a non-weak alias in this case
+void both(void) __attribute((alias("__both")));
+#pragma weak both = __both
+void __both(void) {}
+// RUN: grep '@both = alias void ()\* @__both\>' %t | count 1 &&
+// RUN: grep 'define void @__both() nounwind {' %t | count 1 &&
+
+// if the TARGET is previously declared then whichever aliasing method
+// comes first applies and subsequent aliases are discarded.
+// TODO: warn about this
+
+void __both2(void);
+void both2(void) __attribute((alias("__both2"))); // first, wins
+#pragma weak both2 = __both2
+void __both2(void) {}
+// RUN: grep '@both2 = alias void ()\* @__both2\>' %t | count 1 &&
+// RUN: grep 'define void @__both2() nounwind {' %t | count 1 &&
+
+void __both3(void);
+#pragma weak both3 = __both3 // first, wins
+void both3(void) __attribute((alias("__both3")));
+void __both3(void) {}
+// RUN: grep '@both3 = alias weak void ()\* @__both3\>' %t | count 1 &&
+// RUN: grep 'define void @__both3() nounwind {' %t | count 1 &&
+
+///////////// ensure that #pragma weak does not alter existing __attributes()
+
+void __a1(void) __attribute((noinline));
+#pragma weak a1 = __a1
+void __a1(void) {}
+// RUN: grep '@a1 = alias weak void ()\* @__a1\>' %t | count 1 &&
+// RUN: grep 'define void @__a1() nounwind noinline {' %t | count 1 &&
+
+// attributes introduced BEFORE a combination of #pragma weak and alias()
+// hold...
+void __a3(void) __attribute((noinline));
+#pragma weak a3 = __a3
+void a3(void) __attribute((alias("__a3")));
+void __a3(void) {}
+// RUN: grep '@a3 = alias weak void ()\* @__a3\>' %t | count 1 &&
+// RUN: grep 'define void @__a3() nounwind noinline {' %t | count 1 &&
+
+#pragma weak xxx = __xxx
+__attribute((pure,noinline,const,fastcall)) void __xxx(void) { }
+// RUN: grep '@xxx = alias weak void ()\* @__xxx\>' %t | count 1 &&
+// RUN: grep 'define .*fastcall.* void @__xxx() nounwind readnone noinline {' %t | count 1 &&
+
+/// TODO: stuff that still doesn't work
+
+// due to the fact that disparate TopLevelDecls cannot affect each other
+// (due to clang's Parser and ASTConsumer behavior, and quite reasonable)
+// #pragma weak must appear before or within the same TopLevelDecl as it
+// references.
+void yyy(void){}
+void zzz(void){}
+#pragma weak yyy
+// NOTE: weak doesn't apply, not before or in same TopLevelDec(!)
+// RUN: grep 'define void @yyy() nounwind {' %t | count 1