1 //===- AsmWriterInst.h - Classes encapsulating a printable inst -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // These classes implement a parser for assembly strings.
12 //===----------------------------------------------------------------------===//
14 #include "AsmWriterInst.h"
15 #include "CodeGenTarget.h"
17 #include "llvm/ADT/StringExtras.h"
21 static bool isIdentChar(char C) {
22 return (C >= 'a' && C <= 'z') ||
23 (C >= 'A' && C <= 'Z') ||
24 (C >= '0' && C <= '9') ||
28 std::string AsmWriterOperand::getCode() const {
29 if (OperandType == isLiteralTextOperand) {
31 return "O << '" + Str + "'; ";
32 return "O << \"" + Str + "\"; ";
35 if (OperandType == isLiteralStatementOperand)
38 std::string Result = Str + "(MI";
40 Result += ", " + utostr(MIOpNo);
41 if (!MiModifier.empty())
42 Result += ", \"" + MiModifier + '"';
43 return Result + "); ";
46 /// ParseAsmString - Parse the specified Instruction's AsmString into this
49 AsmWriterInst::AsmWriterInst(const CodeGenInstruction &CGI,
51 int FirstOperandColumn,
55 unsigned CurVariant = ~0U; // ~0 if we are outside a {.|.|.} region, other #.
57 // This is the number of tabs we've seen if we're doing columnar layout.
58 unsigned CurColumn = 0;
61 // NOTE: Any extensions to this code need to be mirrored in the
62 // AsmPrinter::printInlineAsm code that executes as compile time (assuming
63 // that inline asm strings should also get the new feature)!
64 const std::string &AsmString = CGI.AsmString;
65 std::string::size_type LastEmitted = 0;
66 while (LastEmitted != AsmString.size()) {
67 std::string::size_type DollarPos =
68 AsmString.find_first_of("${|}\\", LastEmitted);
69 if (DollarPos == std::string::npos) DollarPos = AsmString.size();
71 // Emit a constant string fragment.
73 if (DollarPos != LastEmitted) {
74 if (CurVariant == Variant || CurVariant == ~0U) {
75 for (; LastEmitted != DollarPos; ++LastEmitted)
76 switch (AsmString[LastEmitted]) {
78 AddLiteralString("\\n");
81 // If the asm writer is not using a columnar layout, \t is not
83 if (FirstOperandColumn == -1 || OperandSpacing == -1) {
84 AddLiteralString("\\t");
86 // We recognize a tab as an operand delimeter.
87 unsigned DestColumn = FirstOperandColumn +
88 CurColumn++ * OperandSpacing;
92 utostr(DestColumn) + ");\n",
93 AsmWriterOperand::isLiteralStatementOperand));
97 AddLiteralString("\\\"");
100 AddLiteralString("\\\\");
103 AddLiteralString(std::string(1, AsmString[LastEmitted]));
107 LastEmitted = DollarPos;
109 } else if (AsmString[DollarPos] == '\\') {
110 if (DollarPos+1 != AsmString.size() &&
111 (CurVariant == Variant || CurVariant == ~0U)) {
112 if (AsmString[DollarPos+1] == 'n') {
113 AddLiteralString("\\n");
114 } else if (AsmString[DollarPos+1] == 't') {
115 // If the asm writer is not using a columnar layout, \t is not
117 if (FirstOperandColumn == -1 || OperandSpacing == -1) {
118 AddLiteralString("\\t");
122 // We recognize a tab as an operand delimeter.
123 unsigned DestColumn = FirstOperandColumn +
124 CurColumn++ * OperandSpacing;
126 AsmWriterOperand("O.PadToColumn(" + utostr(DestColumn) + ");\n",
127 AsmWriterOperand::isLiteralStatementOperand));
129 } else if (std::string("${|}\\").find(AsmString[DollarPos+1])
130 != std::string::npos) {
131 AddLiteralString(std::string(1, AsmString[DollarPos+1]));
133 throw "Non-supported escaped character found in instruction '" +
134 CGI.TheDef->getName() + "'!";
136 LastEmitted = DollarPos+2;
139 } else if (AsmString[DollarPos] == '{') {
140 if (CurVariant != ~0U)
141 throw "Nested variants found for instruction '" +
142 CGI.TheDef->getName() + "'!";
143 LastEmitted = DollarPos+1;
144 CurVariant = 0; // We are now inside of the variant!
145 } else if (AsmString[DollarPos] == '|') {
146 if (CurVariant == ~0U)
147 throw "'|' character found outside of a variant in instruction '"
148 + CGI.TheDef->getName() + "'!";
151 } else if (AsmString[DollarPos] == '}') {
152 if (CurVariant == ~0U)
153 throw "'}' character found outside of a variant in instruction '"
154 + CGI.TheDef->getName() + "'!";
157 } else if (DollarPos+1 != AsmString.size() &&
158 AsmString[DollarPos+1] == '$') {
159 if (CurVariant == Variant || CurVariant == ~0U) {
160 AddLiteralString("$"); // "$$" -> $
162 LastEmitted = DollarPos+2;
164 // Get the name of the variable.
165 std::string::size_type VarEnd = DollarPos+1;
167 // handle ${foo}bar as $foo by detecting whether the character following
168 // the dollar sign is a curly brace. If so, advance VarEnd and DollarPos
169 // so the variable name does not contain the leading curly brace.
170 bool hasCurlyBraces = false;
171 if (VarEnd < AsmString.size() && '{' == AsmString[VarEnd]) {
172 hasCurlyBraces = true;
177 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
179 std::string VarName(AsmString.begin()+DollarPos+1,
180 AsmString.begin()+VarEnd);
182 // Modifier - Support ${foo:modifier} syntax, where "modifier" is passed
183 // into printOperand. Also support ${:feature}, which is passed into
185 std::string Modifier;
187 // In order to avoid starting the next string at the terminating curly
188 // brace, advance the end position past it if we found an opening curly
190 if (hasCurlyBraces) {
191 if (VarEnd >= AsmString.size())
192 throw "Reached end of string before terminating curly brace in '"
193 + CGI.TheDef->getName() + "'";
195 // Look for a modifier string.
196 if (AsmString[VarEnd] == ':') {
198 if (VarEnd >= AsmString.size())
199 throw "Reached end of string before terminating curly brace in '"
200 + CGI.TheDef->getName() + "'";
202 unsigned ModifierStart = VarEnd;
203 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
205 Modifier = std::string(AsmString.begin()+ModifierStart,
206 AsmString.begin()+VarEnd);
207 if (Modifier.empty())
208 throw "Bad operand modifier name in '"+ CGI.TheDef->getName() + "'";
211 if (AsmString[VarEnd] != '}')
212 throw "Variable name beginning with '{' did not end with '}' in '"
213 + CGI.TheDef->getName() + "'";
216 if (VarName.empty() && Modifier.empty())
217 throw "Stray '$' in '" + CGI.TheDef->getName() +
218 "' asm string, maybe you want $$?";
220 if (VarName.empty()) {
221 // Just a modifier, pass this into PrintSpecial.
222 Operands.push_back(AsmWriterOperand("PrintSpecial",
227 // Otherwise, normal operand.
228 unsigned OpNo = CGI.getOperandNamed(VarName);
229 CodeGenInstruction::OperandInfo OpInfo = CGI.OperandList[OpNo];
231 if (CurVariant == Variant || CurVariant == ~0U) {
232 unsigned MIOp = OpInfo.MIOperandNo;
233 Operands.push_back(AsmWriterOperand(OpInfo.PrinterMethodName,
239 LastEmitted = VarEnd;
243 Operands.push_back(AsmWriterOperand("return;",
244 AsmWriterOperand::isLiteralStatementOperand));
247 /// MatchesAllButOneOp - If this instruction is exactly identical to the
248 /// specified instruction except for one differing operand, return the differing
249 /// operand number. If more than one operand mismatches, return ~1, otherwise
250 /// if the instructions are identical return ~0.
251 unsigned AsmWriterInst::MatchesAllButOneOp(const AsmWriterInst &Other)const{
252 if (Operands.size() != Other.Operands.size()) return ~1;
254 unsigned MismatchOperand = ~0U;
255 for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
256 if (Operands[i] != Other.Operands[i]) {
257 if (MismatchOperand != ~0U) // Already have one mismatch?
263 return MismatchOperand;