Add simple support for keeping MCFixup source information.

Can be used to issue more user friendly diagnostics for faulty
relocation constructs and such.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149092 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCContext.h

@@ -15,6 +15,8 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Allocator.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/SMLoc.h"
 #include "llvm/Support/raw_ostream.h"
 #include <vector> // FIXME: Shouldn't be needed.
 
@@ -319,6 +321,11 @@ namespace llvm {
     }
     void Deallocate(void *Ptr) {
     }
+
+    // Unrecoverable error has occured. Display the best diagnostic we can
+    // and bail via exit(1). For now, most MC backend errors are unrecoverable.
+    // FIXME: We should really do something about that.
+    LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg);
   };
 
 } // end namespace llvm

include/llvm/MC/MCFixup.h

@@ -11,6 +11,7 @@
 #define LLVM_MC_MCFIXUP_H
 
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/SMLoc.h"
 #include <cassert>
 
 namespace llvm {
@@ -69,14 +70,17 @@ class MCFixup {
   /// determine how the operand value should be encoded into the instruction.
   unsigned Kind;
 
+  /// The source location which gave rise to the fixup, if any.
+  SMLoc Loc;
 public:
   static MCFixup Create(uint32_t Offset, const MCExpr *Value,
-                        MCFixupKind Kind) {
+                        MCFixupKind Kind, SMLoc Loc = SMLoc()) {
     assert(unsigned(Kind) < MaxTargetFixupKind && "Kind out of range!");
     MCFixup FI;
     FI.Value = Value;
     FI.Offset = Offset;
     FI.Kind = unsigned(Kind);
+    FI.Loc = Loc;
     return FI;
   }
 
@@ -98,6 +102,8 @@ public:
     case 8: return isPCRel ? FK_PCRel_8 : FK_Data_8;
     }
   }
+
+  SMLoc getLoc() const { return Loc; }
 };
 
 } // End llvm namespace

include/llvm/MC/MCInst.h

@@ -19,6 +19,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/SMLoc.h"
 
 namespace llvm {
 class raw_ostream;
@@ -148,14 +149,17 @@ template <> struct isPodLike<MCOperand> { static const bool value = true; };
 /// instruction.
 class MCInst {
   unsigned Opcode;
+  SMLoc Loc;
   SmallVector<MCOperand, 8> Operands;
 public:
   MCInst() : Opcode(0) {}
 
   void setOpcode(unsigned Op) { Opcode = Op; }
-
   unsigned getOpcode() const { return Opcode; }
 
+  void setLoc(SMLoc loc) { Loc = loc; }
+  SMLoc getLoc() const { return Loc; }
+
   const MCOperand &getOperand(unsigned i) const { return Operands[i]; }
   MCOperand &getOperand(unsigned i) { return Operands[i]; }
   unsigned getNumOperands() const { return Operands.size(); }

lib/MC/MCContext.cpp

@@ -20,6 +20,9 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/ELF.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/Signals.h"
 using namespace llvm;
 
 typedef StringMap<const MCSectionMachO*> MachOUniqueMapTy;
@@ -321,3 +324,19 @@ bool MCContext::isValidDwarfFileNumber(unsigned FileNumber) {
 
   return MCDwarfFiles[FileNumber] != 0;
 }
+
+void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
+  // If we have a source manager and a location, use it. Otherwise just
+  // use the generic report_fatal_error().
+  if (!SrcMgr || Loc == SMLoc())
+    report_fatal_error(Msg);
+
+  // Use the source manager to print the message.
+  SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
+
+  // If we reached here, we are failing ungracefully. Run the interrupt handlers
+  // to make sure any special cleanups get done, in particular that we remove
+  // files registered with RemoveFileOnSignal.
+  sys::RunInterruptHandlers();
+  exit(1);
+}