llvm-6502/lib/MC/MCNullStreamer.cpp
Rafael Espindola 5e195a4c8d Remove some really nasty uses of hasRawTextSupport.
When MC was first added, targets could use hasRawTextSupport to keep features
working before they were added to the MC interface.

The design goal of MC is to provide an uniform api for printing assembly and
object files. Short of relaxations and other corner cases, a object file is
just another representation of the assembly.

It was never the intention that targets would keep doing things like

if (hasRawTextSupport())
  Set flags in one way.
else
  Set flags in another way.

When they do that they create two code paths and the object file is no longer
just another representation of the assembly. This also then requires testing
with llc -filetype=obj, which is extremelly brittle.

This patch removes some of these hacks by replacing them with smaller ones.
The ARM flag setting is trivial, so I just moved it to the constructor. For
Mips, the patch adds two temporary hack directives that allow the assembly
to represent the same things as the object file was already able to.

The hope is that the mips developers will replace the hack directives with
the same ones that gas uses and drop the -print-hack-directives flag.

I will also try to implement a target streamer interface, so that we can
move this out of the common code.

In summary, for any new work, two rules of the thumb are
  * Don't use "llc -filetype=obj" in tests.
  * Don't add calls to hasRawTextSupport.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192035 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-05 16:42:21 +00:00

119 lines
4.5 KiB
C++

//===- lib/MC/MCNullStreamer.cpp - Dummy Streamer Implementation ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
using namespace llvm;
namespace {
class MCNullStreamer : public MCStreamer {
public:
MCNullStreamer(MCContext &Context) : MCStreamer(Context) {}
/// @name MCStreamer Interface
/// @{
virtual void InitToTextSection() {
}
virtual void InitSections() {
}
virtual void ChangeSection(const MCSection *Section,
const MCExpr *Subsection) {
}
virtual void EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
assert(getCurrentSection().first &&"Cannot emit before setting section!");
AssignSection(Symbol, getCurrentSection().first);
}
virtual void EmitDebugLabel(MCSymbol *Symbol) {
EmitLabel(Symbol);
}
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
virtual void EmitThumbFunc(MCSymbol *Func) {}
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *LastLabel,
const MCSymbol *Label,
unsigned PointerSize) {}
virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){
return true;
}
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
virtual void EmitCOFFSymbolType(int Type) {}
virtual void EndCOFFSymbolDef() {}
virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {}
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {}
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {}
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
uint64_t Size = 0, unsigned ByteAlignment = 0) {}
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {}
virtual void EmitBytes(StringRef Data) {}
virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
virtual void EmitULEB128Value(const MCExpr *Value) {}
virtual void EmitSLEB128Value(const MCExpr *Value) {}
virtual void EmitGPRel32Value(const MCExpr *Value) {}
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0) {}
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit = 0) {}
virtual bool EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0) { return false; }
virtual void EmitFileDirective(StringRef Filename) {}
virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
StringRef Filename, unsigned CUID = 0) {
return false;
}
virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
unsigned Column, unsigned Flags,
unsigned Isa, unsigned Discriminator,
StringRef FileName) {}
virtual void EmitInstruction(const MCInst &Inst) {}
virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
virtual void EmitBundleLock(bool AlignToEnd) {}
virtual void EmitBundleUnlock() {}
virtual void FinishImpl() {}
virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
RecordProcEnd(Frame);
}
};
}
MCStreamer *llvm::createNullStreamer(MCContext &Context) {
return new MCNullStreamer(Context);
}