1 //===- AsmWriterInst.h - Classes encapsulating a printable inst -----------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // These classes implement a parser for assembly strings. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "AsmWriterInst.h" 14 #include "CodeGenTarget.h" 15 #include "llvm/ADT/StringExtras.h" 16 #include "llvm/TableGen/Error.h" 17 #include "llvm/TableGen/Record.h" 18 19 using namespace llvm; 20 21 static bool isIdentChar(char C) { 22 return (C >= 'a' && C <= 'z') || 23 (C >= 'A' && C <= 'Z') || 24 (C >= '0' && C <= '9') || 25 C == '_'; 26 } 27 28 std::string AsmWriterOperand::getCode(bool PassSubtarget) const { 29 if (OperandType == isLiteralTextOperand) { 30 if (Str.size() == 1) 31 return "O << '" + Str + "';"; 32 return "O << \"" + Str + "\";"; 33 } 34 35 if (OperandType == isLiteralStatementOperand) 36 return Str; 37 38 std::string Result = Str + "(MI"; 39 if (PCRel) 40 Result += ", Address"; 41 if (MIOpNo != ~0U) 42 Result += ", " + utostr(MIOpNo); 43 if (PassSubtarget) 44 Result += ", STI"; 45 Result += ", O"; 46 if (!MiModifier.empty()) 47 Result += ", \"" + MiModifier + '"'; 48 return Result + ");"; 49 } 50 51 /// ParseAsmString - Parse the specified Instruction's AsmString into this 52 /// AsmWriterInst. 53 /// 54 AsmWriterInst::AsmWriterInst(const CodeGenInstruction &CGI, unsigned CGIIndex, 55 unsigned Variant) 56 : CGI(&CGI), CGIIndex(CGIIndex) { 57 58 // NOTE: Any extensions to this code need to be mirrored in the 59 // AsmPrinter::printInlineAsm code that executes as compile time (assuming 60 // that inline asm strings should also get the new feature)! 61 std::string AsmString = CGI.FlattenAsmStringVariants(CGI.AsmString, Variant); 62 std::string::size_type LastEmitted = 0; 63 while (LastEmitted != AsmString.size()) { 64 std::string::size_type DollarPos = 65 AsmString.find_first_of("$\\", LastEmitted); 66 if (DollarPos == std::string::npos) DollarPos = AsmString.size(); 67 68 // Emit a constant string fragment. 69 if (DollarPos != LastEmitted) { 70 for (; LastEmitted != DollarPos; ++LastEmitted) 71 switch (AsmString[LastEmitted]) { 72 case '\n': 73 AddLiteralString("\\n"); 74 break; 75 case '\t': 76 AddLiteralString("\\t"); 77 break; 78 case '"': 79 AddLiteralString("\\\""); 80 break; 81 case '\\': 82 AddLiteralString("\\\\"); 83 break; 84 default: 85 AddLiteralString(std::string(1, AsmString[LastEmitted])); 86 break; 87 } 88 } else if (AsmString[DollarPos] == '\\') { 89 if (DollarPos+1 != AsmString.size()) { 90 if (AsmString[DollarPos+1] == 'n') { 91 AddLiteralString("\\n"); 92 } else if (AsmString[DollarPos+1] == 't') { 93 AddLiteralString("\\t"); 94 } else if (std::string("${|}\\").find(AsmString[DollarPos+1]) 95 != std::string::npos) { 96 AddLiteralString(std::string(1, AsmString[DollarPos+1])); 97 } else { 98 PrintFatalError( 99 CGI.TheDef->getLoc(), 100 "Non-supported escaped character found in instruction '" + 101 CGI.TheDef->getName() + "'!"); 102 } 103 LastEmitted = DollarPos+2; 104 continue; 105 } 106 } else if (DollarPos+1 != AsmString.size() && 107 AsmString[DollarPos+1] == '$') { 108 AddLiteralString("$"); // "$$" -> $ 109 LastEmitted = DollarPos+2; 110 } else { 111 // Get the name of the variable. 112 std::string::size_type VarEnd = DollarPos+1; 113 114 // handle ${foo}bar as $foo by detecting whether the character following 115 // the dollar sign is a curly brace. If so, advance VarEnd and DollarPos 116 // so the variable name does not contain the leading curly brace. 117 bool hasCurlyBraces = false; 118 if (VarEnd < AsmString.size() && '{' == AsmString[VarEnd]) { 119 hasCurlyBraces = true; 120 ++DollarPos; 121 ++VarEnd; 122 } 123 124 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd])) 125 ++VarEnd; 126 StringRef VarName(AsmString.data()+DollarPos+1, VarEnd-DollarPos-1); 127 128 // Modifier - Support ${foo:modifier} syntax, where "modifier" is passed 129 // into printOperand. Also support ${:feature}, which is passed into 130 // PrintSpecial. 131 std::string Modifier; 132 133 // In order to avoid starting the next string at the terminating curly 134 // brace, advance the end position past it if we found an opening curly 135 // brace. 136 if (hasCurlyBraces) { 137 if (VarEnd >= AsmString.size()) 138 PrintFatalError( 139 CGI.TheDef->getLoc(), 140 "Reached end of string before terminating curly brace in '" + 141 CGI.TheDef->getName() + "'"); 142 143 // Look for a modifier string. 144 if (AsmString[VarEnd] == ':') { 145 ++VarEnd; 146 if (VarEnd >= AsmString.size()) 147 PrintFatalError( 148 CGI.TheDef->getLoc(), 149 "Reached end of string before terminating curly brace in '" + 150 CGI.TheDef->getName() + "'"); 151 152 std::string::size_type ModifierStart = VarEnd; 153 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd])) 154 ++VarEnd; 155 Modifier = std::string(AsmString.begin()+ModifierStart, 156 AsmString.begin()+VarEnd); 157 if (Modifier.empty()) 158 PrintFatalError(CGI.TheDef->getLoc(), 159 "Bad operand modifier name in '" + 160 CGI.TheDef->getName() + "'"); 161 } 162 163 if (AsmString[VarEnd] != '}') 164 PrintFatalError( 165 CGI.TheDef->getLoc(), 166 "Variable name beginning with '{' did not end with '}' in '" + 167 CGI.TheDef->getName() + "'"); 168 ++VarEnd; 169 } 170 if (VarName.empty() && Modifier.empty()) 171 PrintFatalError(CGI.TheDef->getLoc(), 172 "Stray '$' in '" + CGI.TheDef->getName() + 173 "' asm string, maybe you want $$?"); 174 175 if (VarName.empty()) { 176 // Just a modifier, pass this into PrintSpecial. 177 Operands.emplace_back("PrintSpecial", ~0U, Modifier); 178 } else { 179 // Otherwise, normal operand. 180 unsigned OpNo = CGI.Operands.getOperandNamed(VarName); 181 CGIOperandList::OperandInfo OpInfo = CGI.Operands[OpNo]; 182 183 unsigned MIOp = OpInfo.MIOperandNo; 184 Operands.emplace_back(OpInfo.PrinterMethodName, MIOp, Modifier, 185 AsmWriterOperand::isMachineInstrOperand, 186 OpInfo.OperandType == "MCOI::OPERAND_PCREL"); 187 } 188 LastEmitted = VarEnd; 189 } 190 } 191 192 Operands.emplace_back("return;", AsmWriterOperand::isLiteralStatementOperand); 193 } 194 195 /// MatchesAllButOneOp - If this instruction is exactly identical to the 196 /// specified instruction except for one differing operand, return the differing 197 /// operand number. If more than one operand mismatches, return ~1, otherwise 198 /// if the instructions are identical return ~0. 199 unsigned AsmWriterInst::MatchesAllButOneOp(const AsmWriterInst &Other)const{ 200 if (Operands.size() != Other.Operands.size()) return ~1; 201 202 unsigned MismatchOperand = ~0U; 203 for (unsigned i = 0, e = Operands.size(); i != e; ++i) { 204 if (Operands[i] != Other.Operands[i]) { 205 if (MismatchOperand != ~0U) // Already have one mismatch? 206 return ~1U; 207 MismatchOperand = i; 208 } 209 } 210 return MismatchOperand; 211 } 212