COFF: Produce an error on invalid pcrel relocs.

X86_64 COFF only has support for 32 bit pcrel relocations. Produce an
error on all others.

Note that gnu as has extended the relocation values to support
this. It is not clear if we should support the gnu extension.

llvm-svn: 306082

3 files changed, 19 insertions, 9 deletions

diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index 8d8c5ff9b60..fc523495039 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -781,8 +781,8 @@ void WinCOFFObjectWriter::recordRelocation(
   ++Reloc.Symb->Relocations;
 
   Reloc.Data.VirtualAddress += Fixup.getOffset();
-  Reloc.Data.Type =
-      TargetObjectWriter->getRelocType(Target, Fixup, SymB, Asm.getBackend());
+  Reloc.Data.Type = TargetObjectWriter->getRelocType(
+      Asm.getContext(), Target, Fixup, SymB, Asm.getBackend());
 
   // FIXME: Can anyone explain what this does other than adjust for the size
   // of the offset?
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFObjectWriter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFObjectWriter.cpp
index 00505a103e0..f74fb2e20b5 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFObjectWriter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMWinCOFFObjectWriter.cpp
@@ -33,8 +33,8 @@ public:
 
   ~ARMWinCOFFObjectWriter() override = default;
 
-  unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup,
-                        bool IsCrossSection,
+  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
+                        const MCFixup &Fixup, bool IsCrossSection,
                         const MCAsmBackend &MAB) const override;
 
   bool recordRelocation(const MCFixup &) const override;
@@ -42,7 +42,8 @@ public:
 
 } // end anonymous namespace
 
-unsigned ARMWinCOFFObjectWriter::getRelocType(const MCValue &Target,
+unsigned ARMWinCOFFObjectWriter::getRelocType(MCContext &Ctx,
+                                              const MCValue &Target,
                                               const MCFixup &Fixup,
                                               bool IsCrossSection,
                                               const MCAsmBackend &MAB) const {
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
index 105580c913a..5892f1de33e 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
@@ -10,6 +10,7 @@
 #include "MCTargetDesc/X86FixupKinds.h"
 #include "MCTargetDesc/X86MCTargetDesc.h"
 #include "llvm/BinaryFormat/COFF.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixup.h"
 #include "llvm/MC/MCValue.h"
@@ -25,8 +26,8 @@ public:
   X86WinCOFFObjectWriter(bool Is64Bit);
   ~X86WinCOFFObjectWriter() override = default;
 
-  unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup,
-                        bool IsCrossSection,
+  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
+                        const MCFixup &Fixup, bool IsCrossSection,
                         const MCAsmBackend &MAB) const override;
 };
 
@@ -36,11 +37,19 @@ X86WinCOFFObjectWriter::X86WinCOFFObjectWriter(bool Is64Bit)
     : MCWinCOFFObjectTargetWriter(Is64Bit ? COFF::IMAGE_FILE_MACHINE_AMD64
                                           : COFF::IMAGE_FILE_MACHINE_I386) {}
 
-unsigned X86WinCOFFObjectWriter::getRelocType(const MCValue &Target,
+unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx,
+                                              const MCValue &Target,
                                               const MCFixup &Fixup,
                                               bool IsCrossSection,
                                               const MCAsmBackend &MAB) const {
-  unsigned FixupKind = IsCrossSection ? FK_PCRel_4 : Fixup.getKind();
+  unsigned FixupKind = Fixup.getKind();
+  if (IsCrossSection) {
+    if (FixupKind != FK_Data_4) {
+      Ctx.reportError(Fixup.getLoc(), "Cannot represent this expression");
+      return COFF::IMAGE_REL_AMD64_ADDR32;
+    }
+    FixupKind = FK_PCRel_4;
+  }
 
   MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
     MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();