From 1ac7fe0f4dae8a9266fa6ff31ea4939ec64a3e5e Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 21 Apr 2011 18:36:50 +0000
Subject: [PATCH] Fix relative relocations. This is sufficient for running the
 rust testsuite with MC :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129923 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/MC/WinCOFFObjectWriter.cpp |  7 ++++++-
 test/MC/COFF/diff.s            | 24 +++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index fe3342c886b..101237aabb0 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -656,8 +656,13 @@ void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
     const MCSymbol *B = &Target.getSymB()->getSymbol();
     MCSymbolData &B_SD = Asm.getSymbolData(*B);
 
-    FixedValue = Layout.getSymbolOffset(&A_SD) - Layout.getSymbolOffset(&B_SD);
+    // Offset of the symbol in the section
+    int64_t a = Layout.getSymbolOffset(&B_SD);
 
+    // Ofeset of the relocation in the section
+    int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
+
+    FixedValue = b - a;
     // In the case where we have SymbA and SymB, we just need to store the delta
     // between the two symbols.  Update FixedValue to account for the delta, and
     // skip recording the relocation.
diff --git a/test/MC/COFF/diff.s b/test/MC/COFF/diff.s
index b7db5097fd6..aa683f26a7b 100644
--- a/test/MC/COFF/diff.s
+++ b/test/MC/COFF/diff.s
@@ -5,6 +5,7 @@
 	.type	32;
 	.endef
 	.text
+	.long   0
 	.globl	_foobar
 	.align	16, 0x90
 _foobar:                                # @foobar
@@ -15,13 +16,30 @@ _foobar:                                # @foobar
 	.globl	_rust_crate             # @rust_crate
 	.align	4
 _rust_crate:
+	.long   0
+	.long   _foobar
+	.long	_foobar-_rust_crate
 	.long	_foobar-_rust_crate
 
-
-// CHECK:       Relocations              = [
+// CHECK:      Name                     = .data
+// CHECK:      SectionData              =
+// CHECK-NEXT:   00 00 00 00 00 00 00 00 - 1C 00 00 00 20 00 00 00 |............ ...|
+// CHECK:        Relocations              = [
 // CHECK-NEXT:   0 = {
-// CHECK-NEXT:     VirtualAddress           = 0x0
+// CHECK-NEXT:     VirtualAddress           = 0x4
 // CHECK-NEXT:     SymbolTableIndex         =
+// CHECK-NEXT:     Type                     = IMAGE_REL_I386_DIR32 (6)
+// CHECK-NEXT:     SymbolName               = _foobar
+// CHECK-NEXT:   }
+// CHECK-NEXT:   1 = {
+// CHECK-NEXT:     VirtualAddress           = 0x8
+// CHECK-NEXT:     SymbolTableIndex         = 0
+// CHECK-NEXT:     Type                     = IMAGE_REL_I386_REL32 (20)
+// CHECK-NEXT:     SymbolName               = .text
+// CHECK-NEXT:   }
+// CHECK-NEXT:   2 = {
+// CHECK-NEXT:     VirtualAddress           = 0xC
+// CHECK-NEXT:     SymbolTableIndex         = 0
 // CHECK-NEXT:     Type                     = IMAGE_REL_I386_REL32 (20)
 // CHECK-NEXT:     SymbolName               = .text
 // CHECK-NEXT:   }
-- 
2.34.1