coff: fix weak alias to local.

We were creating a weak external that tried to reference a static symbol. That
would always fail to link with link.exe.

We now create an external symbol in the same position as the local and refer
to that. This works with link.exe and matches what gas does.

llvm-svn: 270906

2 files changed, 64 insertions, 1 deletions

diff --git a/llvm/test/MC/COFF/weak-alias-local.s b/llvm/test/MC/COFF/weak-alias-local.s
new file mode 100644
index 00000000000..01f2ac390a5
--- /dev/null
+++ b/llvm/test/MC/COFF/weak-alias-local.s
@@ -0,0 +1,43 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-win32 %s -o %t.o
+// RUN: llvm-readobj -t %t.o | FileCheck %s
+
+// test that we create an external symbol for a to point to.
+
+        .data
+        .long 123
+b:
+        .long   42
+        .weak   a
+a=b
+
+// CHECK:      Symbol {
+// CHECK:        Name: b
+// CHECK-NEXT:   Value: 4
+// CHECK-NEXT:   Section: .data (2)
+// CHECK-NEXT:   BaseType: Null (0x0)
+// CHECK-NEXT:   ComplexType: Null (0x0)
+// CHECK-NEXT:   StorageClass: Static (0x3)
+// CHECK-NEXT:   AuxSymbolCount: 0
+// CHECK-NEXT: }
+// CHECK-NEXT: Symbol {
+// CHECK-NEXT:   Name: a
+// CHECK-NEXT:   Value: 0
+// CHECK-NEXT:   Section: IMAGE_SYM_UNDEFINED (0)
+// CHECK-NEXT:   BaseType: Null (0x0)
+// CHECK-NEXT:   ComplexType: Null (0x0)
+// CHECK-NEXT:   StorageClass: WeakExternal (0x69)
+// CHECK-NEXT:   AuxSymbolCount: 1
+// CHECK-NEXT:   AuxWeakExternal {
+// CHECK-NEXT:     Linked: .weak.a.default (9)
+// CHECK-NEXT:     Search: Library (0x2)
+// CHECK-NEXT:   }
+// CHECK-NEXT: }
+// CHECK-NEXT: Symbol {
+// CHECK-NEXT:   Name: .weak.a.default
+// CHECK-NEXT:   Value: 4
+// CHECK-NEXT:   Section: .data (2)
+// CHECK-NEXT:   BaseType: Null (0x0)
+// CHECK-NEXT:   ComplexType: Null (0x0)
+// CHECK-NEXT:   StorageClass: External (0x2)
+// CHECK-NEXT:   AuxSymbolCount: 0
+// CHECK-NEXT: }
diff --git a/llvm/test/MC/COFF/weak.s b/llvm/test/MC/COFF/weak.s
index 6086749d80d..e0d077840f1 100644
--- a/llvm/test/MC/COFF/weak.s
+++ b/llvm/test/MC/COFF/weak.s
@@ -35,6 +35,16 @@ LBB0_2:                                 # %return
 // CHECK: Symbols [
 
 // CHECK:      Symbol {
+// CHECK:        Name: _main
+// CHECK-NEXT:   Value: 0
+// CHECK-NEXT:   Section: .text
+// CHECK-NEXT:   BaseType: Null
+// CHECK-NEXT:   ComplexType: Function
+// CHECK-NEXT:   StorageClass: External
+// CHECK-NEXT:   AuxSymbolCount: 0
+// CHECK-NEXT: }
+
+// CHECK:      Symbol {
 // CHECK:        Name:           _test_weak
 // CHECK-NEXT:   Value:          0
 // CHECK-NEXT:   Section:        IMAGE_SYM_UNDEFINED (0)
@@ -67,7 +77,17 @@ LBB0_2:                                 # %return
 // CHECK-NEXT:   StorageClass:   WeakExternal
 // CHECK-NEXT:   AuxSymbolCount: 1
 // CHECK-NEXT:   AuxWeakExternal {
-// CHECK-NEXT:     Linked: _main
+// CHECK-NEXT:     Linked: .weak._test_weak_alias.default
 // CHECK-NEXT:      Search: Library
 // CHECK-NEXT:   }
 // CHECK-NEXT: }
+
+// CHECK:      Symbol {
+// CHECK:        Name: .weak._test_weak_alias.default
+// CHECK-NEXT:   Value: 0
+// CHECK-NEXT:   Section: .text
+// CHECK-NEXT:   BaseType: Null
+// CHECK-NEXT:   ComplexType: Null
+// CHECK-NEXT:   StorageClass: External
+// CHECK-NEXT:   AuxSymbolCount: 0
+// CHECK-NEXT: }