1 //===- AsmWriterEmitter.cpp - Generate an assembly writer -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This tablegen backend is emits an assembly printer for the current target.
11 // Note that this is currently fairly skeletal, but will grow over time.
13 //===----------------------------------------------------------------------===//
15 #include "AsmWriterEmitter.h"
16 #include "CodeGenTarget.h"
21 static bool isIdentChar(char C) {
22 return (C >= 'a' && C <= 'z') ||
23 (C >= 'A' && C <= 'Z') ||
24 (C >= '0' && C <= '9') ||
28 void AsmWriterEmitter::run(std::ostream &O) {
29 EmitSourceFileHeader("Assembly Writer Source Fragment", O);
30 O << "namespace llvm {\n\n";
34 Record *AsmWriter = Target.getAsmWriter();
36 std::string AsmWriterClassName =
37 AsmWriter->getValueAsString("AsmWriterClassName");
40 "/// printInstruction - This method is automatically generated by tablegen\n"
41 "/// from the instruction set description. This method returns true if the\n"
42 "/// machine instruction was sufficiently described to print it, otherwise\n"
43 "/// it returns false.\n"
44 "bool " << Target.getName() << AsmWriterClassName
45 << "::printInstruction(const MachineInstr *MI) {\n";
46 O << " switch (MI->getOpcode()) {\n"
47 " default: return false;\n";
49 std::string Namespace = Target.inst_begin()->second.Namespace;
51 for (CodeGenTarget::inst_iterator I = Target.inst_begin(),
52 E = Target.inst_end(); I != E; ++I)
53 if (!I->second.AsmString.empty()) {
54 const std::string &AsmString = I->second.AsmString;
55 O << " case " << Namespace << "::" << I->first << ": O ";
57 std::string::size_type LastEmitted = 0;
58 while (LastEmitted != AsmString.size()) {
59 std::string::size_type DollarPos = AsmString.find('$', LastEmitted);
60 if (DollarPos == std::string::npos) DollarPos = AsmString.size();
62 // Emit a constant string fragment.
63 if (DollarPos != LastEmitted) {
64 // TODO: this should eventually handle escaping.
65 O << " << \"" << std::string(AsmString.begin()+LastEmitted,
66 AsmString.begin()+DollarPos) << "\"";
67 LastEmitted = DollarPos;
68 } else if (DollarPos+1 != AsmString.size() &&
69 AsmString[DollarPos+1] == '$') {
70 O << " << '$'"; // "$$" -> $
72 // Get the name of the variable.
73 // TODO: should eventually handle ${foo}bar as $foo
74 std::string::size_type VarEnd = DollarPos+1;
75 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
77 std::string VarName(AsmString.begin()+DollarPos+1,
78 AsmString.begin()+VarEnd);
80 throw "Stray '$' in '" + I->first +
81 "' asm string, maybe you want $$?";
82 unsigned OpNo = I->second.getOperandNamed(VarName);
84 // If this is a two-address instruction and we are not accessing the
85 // 0th operand, remove an operand.
86 unsigned MIOp = I->second.OperandList[OpNo].MIOperandNo;
87 if (I->second.isTwoAddress && MIOp != 0) {
89 throw "Should refer to operand #0 instead of #1 for two-address"
90 " instruction '" + I->first + "'!";
94 O << "; " << I->second.OperandList[OpNo].PrinterMethodName
95 << "(MI, " << MIOp << ", MVT::"
96 << getName(I->second.OperandList[OpNo].Ty) << "); O ";
101 O << " << '\\n'; break;\n";
107 O << "} // End llvm namespace \n";