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

6 files changed, 39 insertions, 36 deletions

diff --git a/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h b/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h
index 57bed213aad..6e14cefaa0a 100644
--- a/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h
+++ b/llvm/include/llvm/MC/MCWinCOFFObjectWriter.h
@@ -30,8 +30,8 @@ class raw_pwrite_stream;
     virtual ~MCWinCOFFObjectTargetWriter() = default;
 
     unsigned getMachine() const { return Machine; }
-    virtual unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup,
-                                  bool IsCrossSection,
+    virtual unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
+                                  const MCFixup &Fixup, bool IsCrossSection,
                                   const MCAsmBackend &MAB) const = 0;
     virtual bool recordRelocation(const MCFixup &) const { return true; }
   };
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();
diff --git a/llvm/test/MC/COFF/cross-section-relative-err.s b/llvm/test/MC/COFF/cross-section-relative-err.s
new file mode 100644
index 00000000000..e237f60e9a3
--- /dev/null
+++ b/llvm/test/MC/COFF/cross-section-relative-err.s
@@ -0,0 +1,12 @@
+// RUN: not llvm-mc -filetype=obj -triple x86_64-pc-win32 %s -o /dev/null 2>&1 | FileCheck %s
+
+
+// CHECK: [[@LINE+1]]:{{[0-9]+}}: error: Cannot represent this expression
+        .byte foo - .
+
+// CHECK: [[@LINE+1]]:{{[0-9]+}}: error: Cannot represent this expression
+        .short foo - .
+
+// CHECK: [[@LINE+1]]:{{[0-9]+}}: error: Cannot represent this expression
+        .quad foo - .
+
diff --git a/llvm/test/MC/COFF/cross-section-relative.s b/llvm/test/MC/COFF/cross-section-relative.s
index 8d96c8f8df4..6f172922e9b 100644
--- a/llvm/test/MC/COFF/cross-section-relative.s
+++ b/llvm/test/MC/COFF/cross-section-relative.s
@@ -27,17 +27,14 @@ g4:
 	.globl	t1                      # @t1
 	.align	8
 t1:
-	.quad	(g3-t1)+4
 
 	.globl	t2                      # @t2
 	.align	8
 t2:
-	.quad	g3-t2
 
 	.globl	t3                      # @t3
 	.align	8
 t3:
-	.quad	(g3-t3)-4
 
 	.globl	t4                      # @t4
 	.align	4
@@ -78,10 +75,9 @@ t6:
 // READOBJ-NEXT:      IMAGE_SCN_MEM_WRITE (0x80000000)
 // READOBJ-NEXT:    ]
 // READOBJ-NEXT:    SectionData (
-// READOBJ-NEXT:      0000: 08000000 00000000 04000000 00000000  |
-// READOBJ-NEXT:      0010: 00000000 00000000 04000000 00000000  |
-// READOBJ-NEXT:      0020: 01020000 00000000 00010000 00000000  |
-// READOBJ-NEXT:      0030: 04000000 00000000 04000000           |
+// READOBJ-NEXT:      0000: 04000000 00000000 00000000 00000000  |
+// READOBJ-NEXT:      0010: 01020000 00000000 00010000 00000000  |
+// READOBJ-NEXT:      0020: 04000000 00000000 04000000           |
 // READOBJ-NEXT:    )
 // READOBJ-NEXT:  }
 // READOBJ-NEXT:  ]
@@ -93,32 +89,17 @@ t6:
 // READOBJ-NEXT:      Symbol: g3
 // READOBJ-NEXT:    }
 // READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x8
-// READOBJ-NEXT:      Type: IMAGE_REL_AMD64_REL32 (4)
-// READOBJ-NEXT:      Symbol: g3
-// READOBJ-NEXT:    }
-// READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x10
-// READOBJ-NEXT:      Type: IMAGE_REL_AMD64_REL32 (4)
-// READOBJ-NEXT:      Symbol: g3
-// READOBJ-NEXT:    }
-// READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x18
-// READOBJ-NEXT:      Type: IMAGE_REL_AMD64_REL32 (4)
-// READOBJ-NEXT:      Symbol: g3
-// READOBJ-NEXT:    }
-// READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x1C
+// READOBJ-NEXT:      Offset: 0x4
 // READOBJ-NEXT:      Type: IMAGE_REL_AMD64_ADDR32NB (3)
 // READOBJ-NEXT:      Symbol: g3
 // READOBJ-NEXT:    }
 // READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x30
+// READOBJ-NEXT:      Offset: 0x20
 // READOBJ-NEXT:      Type: IMAGE_REL_AMD64_REL32 (4)
 // READOBJ-NEXT:      Symbol: g3
 // READOBJ-NEXT:    }
 // READOBJ-NEXT:    Relocation {
-// READOBJ-NEXT:      Offset: 0x38
+// READOBJ-NEXT:      Offset: 0x28
 // READOBJ-NEXT:      Type: IMAGE_REL_AMD64_REL32 (4)
 // READOBJ-NEXT:      Symbol: foobar
 // READOBJ-NEXT:    }