8f9f8210c1
since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
95 lines
2.8 KiB
C++
95 lines
2.8 KiB
C++
//===-- BPFInstPrinter.cpp - Convert BPF MCInst to asm syntax -------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This class prints an BPF MCInst to a .s file.
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//
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//===----------------------------------------------------------------------===//
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#include "BPF.h"
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#include "BPFInstPrinter.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/FormattedStream.h"
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using namespace llvm;
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#define DEBUG_TYPE "asm-printer"
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// Include the auto-generated portion of the assembly writer.
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#include "BPFGenAsmWriter.inc"
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void BPFInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
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StringRef Annot, const MCSubtargetInfo &STI) {
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printInstruction(MI, O);
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printAnnotation(O, Annot);
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}
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static void printExpr(const MCExpr *Expr, raw_ostream &O) {
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#ifndef NDEBUG
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const MCSymbolRefExpr *SRE;
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if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
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SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
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else
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SRE = dyn_cast<MCSymbolRefExpr>(Expr);
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assert(SRE && "Unexpected MCExpr type.");
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MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
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assert(Kind == MCSymbolRefExpr::VK_None);
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#endif
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O << *Expr;
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}
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void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
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raw_ostream &O, const char *Modifier) {
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assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
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const MCOperand &Op = MI->getOperand(OpNo);
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if (Op.isReg()) {
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O << getRegisterName(Op.getReg());
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} else if (Op.isImm()) {
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O << (int32_t)Op.getImm();
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} else {
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assert(Op.isExpr() && "Expected an expression");
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printExpr(Op.getExpr(), O);
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}
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}
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void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
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const char *Modifier) {
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const MCOperand &RegOp = MI->getOperand(OpNo);
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const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
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// register
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assert(RegOp.isReg() && "Register operand not a register");
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O << getRegisterName(RegOp.getReg());
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// offset
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if (OffsetOp.isImm()) {
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auto Imm = OffsetOp.getImm();
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if (Imm >= 0)
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O << " + " << formatDec(Imm);
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else
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O << " - " << formatDec(-Imm);
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} else {
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assert(0 && "Expected an immediate");
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}
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}
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void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
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raw_ostream &O) {
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const MCOperand &Op = MI->getOperand(OpNo);
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if (Op.isImm())
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O << (uint64_t)Op.getImm();
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else
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O << Op;
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}
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