From b77f8919bc1d246ebce0affe7f81eaf1ebeac725 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 1 May 2014 00:10:17 +0000
Subject: [PATCH] Start fixing pr19147.

This makes the coff writer compute the correct symbol value for the test in
pr19147. The section is still incorrect, that will be fixed in a followup patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207728 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/MC/WinCOFFObjectWriter.cpp | 23 +++++++++++++----------
 test/MC/COFF/offset.s          | 19 +++++++++++++++++++
 2 files changed, 32 insertions(+), 10 deletions(-)
 create mode 100644 test/MC/COFF/offset.s

diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index fc0d51ca076..be7a9c8c0d3 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -385,6 +385,18 @@ void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
   SectionMap[&SectionData.getSection()] = coff_section;
 }
 
+static uint64_t getSymbolValue(const MCSymbolData &Data,
+                               const MCAsmLayout &Layout) {
+  if (Data.isCommon() && Data.isExternal())
+    return Data.getCommonSize();
+
+  uint64_t Res;
+  if (!Layout.getSymbolOffset(&Data, Res))
+    return 0;
+
+  return Res;
+}
+
 /// This function takes a symbol data object from the assembler
 /// and creates the associated COFF symbol staging object.
 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
@@ -429,14 +441,7 @@ void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
   } else {
     const MCSymbolData &ResSymData =
       Assembler.getSymbolData(Symbol.AliasedSymbol());
-
-    if (Symbol.isVariable()) {
-      int64_t Addr;
-      if (Symbol.getVariableValue()->EvaluateAsAbsolute(Addr, Layout))
-        coff_symbol->Data.Value = Addr;
-    } else if (SymbolData.isExternal() && SymbolData.isCommon()) {
-      coff_symbol->Data.Value = SymbolData.getCommonSize();
-    }
+    coff_symbol->Data.Value = getSymbolValue(ResSymData, Layout);
 
     coff_symbol->Data.Type         = (ResSymData.getFlags() & 0x0000FFFF) >>  0;
     coff_symbol->Data.StorageClass = (ResSymData.getFlags() & 0x00FF0000) >> 16;
@@ -828,8 +833,6 @@ void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
       assert(Symbol->Section != nullptr);
 
       Symbol->Data.SectionNumber = Symbol->Section->Number;
-      Symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
-                         + SymbolData->Offset;
     }
 
     if (Symbol->should_keep()) {
diff --git a/test/MC/COFF/offset.s b/test/MC/COFF/offset.s
new file mode 100644
index 00000000000..9e6f42c4ddd
--- /dev/null
+++ b/test/MC/COFF/offset.s
@@ -0,0 +1,19 @@
+// RUN: llvm-mc -filetype=obj -triple i686-pc-win32 %s -o - | llvm-readobj -t -r | FileCheck %s
+
+	.data
+	.globl	test1_foo
+test1_foo:
+        .long 42
+
+        .globl test1_zed
+test1_zed = test1_foo + 1
+
+// CHECK:      Symbol {
+// CHECK:        Name: test1_zed
+// CHECK-NEXT:   Value: 1
+// CHECK-NEXT:   Section:
+// CHECK-NEXT:   BaseType: Null
+// CHECK-NEXT:   ComplexType: Null
+// CHECK-NEXT:   StorageClass: External
+// CHECK-NEXT:   AuxSymbolCount: 0
+// CHECK-NEXT: }