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John Bauman89401822014-05-06 15:04:28 -04001//===- AsmWriterInst.h - Classes encapsulating a printable inst -----------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// These classes implement a parser for assembly strings.
11//
12//===----------------------------------------------------------------------===//
13
14#include "AsmWriterInst.h"
15#include "CodeGenTarget.h"
16#include "Record.h"
17#include "llvm/ADT/StringExtras.h"
18
19using namespace llvm;
20
21static bool isIdentChar(char C) {
22 return (C >= 'a' && C <= 'z') ||
23 (C >= 'A' && C <= 'Z') ||
24 (C >= '0' && C <= '9') ||
25 C == '_';
26}
27
28std::string AsmWriterOperand::getCode() 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 (MIOpNo != ~0U)
40 Result += ", " + utostr(MIOpNo);
41 Result += ", O";
42 if (!MiModifier.empty())
43 Result += ", \"" + MiModifier + '"';
44 return Result + "); ";
45}
46
47/// ParseAsmString - Parse the specified Instruction's AsmString into this
48/// AsmWriterInst.
49///
50AsmWriterInst::AsmWriterInst(const CodeGenInstruction &CGI,
51 unsigned Variant,
52 int FirstOperandColumn,
53 int OperandSpacing) {
54 this->CGI = &CGI;
55
56 unsigned CurVariant = ~0U; // ~0 if we are outside a {.|.|.} region, other #.
57
58 // This is the number of tabs we've seen if we're doing columnar layout.
59 unsigned CurColumn = 0;
60
61
62 // NOTE: Any extensions to this code need to be mirrored in the
63 // AsmPrinter::printInlineAsm code that executes as compile time (assuming
64 // that inline asm strings should also get the new feature)!
65 const std::string &AsmString = CGI.AsmString;
66 std::string::size_type LastEmitted = 0;
67 while (LastEmitted != AsmString.size()) {
68 std::string::size_type DollarPos =
69 AsmString.find_first_of("${|}\\", LastEmitted);
70 if (DollarPos == std::string::npos) DollarPos = AsmString.size();
71
72 // Emit a constant string fragment.
73
74 if (DollarPos != LastEmitted) {
75 if (CurVariant == Variant || CurVariant == ~0U) {
76 for (; LastEmitted != DollarPos; ++LastEmitted)
77 switch (AsmString[LastEmitted]) {
78 case '\n':
79 AddLiteralString("\\n");
80 break;
81 case '\t':
82 // If the asm writer is not using a columnar layout, \t is not
83 // magic.
84 if (FirstOperandColumn == -1 || OperandSpacing == -1) {
85 AddLiteralString("\\t");
86 } else {
87 // We recognize a tab as an operand delimeter.
88 unsigned DestColumn = FirstOperandColumn +
89 CurColumn++ * OperandSpacing;
90 Operands.push_back(
91 AsmWriterOperand(
92 "O.PadToColumn(" +
93 utostr(DestColumn) + ");\n",
94 AsmWriterOperand::isLiteralStatementOperand));
95 }
96 break;
97 case '"':
98 AddLiteralString("\\\"");
99 break;
100 case '\\':
101 AddLiteralString("\\\\");
102 break;
103 default:
104 AddLiteralString(std::string(1, AsmString[LastEmitted]));
105 break;
106 }
107 } else {
108 LastEmitted = DollarPos;
109 }
110 } else if (AsmString[DollarPos] == '\\') {
111 if (DollarPos+1 != AsmString.size() &&
112 (CurVariant == Variant || CurVariant == ~0U)) {
113 if (AsmString[DollarPos+1] == 'n') {
114 AddLiteralString("\\n");
115 } else if (AsmString[DollarPos+1] == 't') {
116 // If the asm writer is not using a columnar layout, \t is not
117 // magic.
118 if (FirstOperandColumn == -1 || OperandSpacing == -1) {
119 AddLiteralString("\\t");
120 break;
121 }
122
123 // We recognize a tab as an operand delimeter.
124 unsigned DestColumn = FirstOperandColumn +
125 CurColumn++ * OperandSpacing;
126 Operands.push_back(
127 AsmWriterOperand("O.PadToColumn(" + utostr(DestColumn) + ");\n",
128 AsmWriterOperand::isLiteralStatementOperand));
129 break;
130 } else if (std::string("${|}\\").find(AsmString[DollarPos+1])
131 != std::string::npos) {
132 AddLiteralString(std::string(1, AsmString[DollarPos+1]));
133 } else {
134 throw "Non-supported escaped character found in instruction '" +
135 CGI.TheDef->getName() + "'!";
136 }
137 LastEmitted = DollarPos+2;
138 continue;
139 }
140 } else if (AsmString[DollarPos] == '{') {
141 if (CurVariant != ~0U)
142 throw "Nested variants found for instruction '" +
143 CGI.TheDef->getName() + "'!";
144 LastEmitted = DollarPos+1;
145 CurVariant = 0; // We are now inside of the variant!
146 } else if (AsmString[DollarPos] == '|') {
147 if (CurVariant == ~0U)
148 throw "'|' character found outside of a variant in instruction '"
149 + CGI.TheDef->getName() + "'!";
150 ++CurVariant;
151 ++LastEmitted;
152 } else if (AsmString[DollarPos] == '}') {
153 if (CurVariant == ~0U)
154 throw "'}' character found outside of a variant in instruction '"
155 + CGI.TheDef->getName() + "'!";
156 ++LastEmitted;
157 CurVariant = ~0U;
158 } else if (DollarPos+1 != AsmString.size() &&
159 AsmString[DollarPos+1] == '$') {
160 if (CurVariant == Variant || CurVariant == ~0U) {
161 AddLiteralString("$"); // "$$" -> $
162 }
163 LastEmitted = DollarPos+2;
164 } else {
165 // Get the name of the variable.
166 std::string::size_type VarEnd = DollarPos+1;
167
168 // handle ${foo}bar as $foo by detecting whether the character following
169 // the dollar sign is a curly brace. If so, advance VarEnd and DollarPos
170 // so the variable name does not contain the leading curly brace.
171 bool hasCurlyBraces = false;
172 if (VarEnd < AsmString.size() && '{' == AsmString[VarEnd]) {
173 hasCurlyBraces = true;
174 ++DollarPos;
175 ++VarEnd;
176 }
177
178 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
179 ++VarEnd;
180 std::string VarName(AsmString.begin()+DollarPos+1,
181 AsmString.begin()+VarEnd);
182
183 // Modifier - Support ${foo:modifier} syntax, where "modifier" is passed
184 // into printOperand. Also support ${:feature}, which is passed into
185 // PrintSpecial.
186 std::string Modifier;
187
188 // In order to avoid starting the next string at the terminating curly
189 // brace, advance the end position past it if we found an opening curly
190 // brace.
191 if (hasCurlyBraces) {
192 if (VarEnd >= AsmString.size())
193 throw "Reached end of string before terminating curly brace in '"
194 + CGI.TheDef->getName() + "'";
195
196 // Look for a modifier string.
197 if (AsmString[VarEnd] == ':') {
198 ++VarEnd;
199 if (VarEnd >= AsmString.size())
200 throw "Reached end of string before terminating curly brace in '"
201 + CGI.TheDef->getName() + "'";
202
203 unsigned ModifierStart = VarEnd;
204 while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
205 ++VarEnd;
206 Modifier = std::string(AsmString.begin()+ModifierStart,
207 AsmString.begin()+VarEnd);
208 if (Modifier.empty())
209 throw "Bad operand modifier name in '"+ CGI.TheDef->getName() + "'";
210 }
211
212 if (AsmString[VarEnd] != '}')
213 throw "Variable name beginning with '{' did not end with '}' in '"
214 + CGI.TheDef->getName() + "'";
215 ++VarEnd;
216 }
217 if (VarName.empty() && Modifier.empty())
218 throw "Stray '$' in '" + CGI.TheDef->getName() +
219 "' asm string, maybe you want $$?";
220
221 if (VarName.empty()) {
222 // Just a modifier, pass this into PrintSpecial.
223 Operands.push_back(AsmWriterOperand("PrintSpecial",
224 ~0U,
225 ~0U,
226 Modifier));
227 } else {
228 // Otherwise, normal operand.
229 unsigned OpNo = CGI.getOperandNamed(VarName);
230 CodeGenInstruction::OperandInfo OpInfo = CGI.OperandList[OpNo];
231
232 if (CurVariant == Variant || CurVariant == ~0U) {
233 unsigned MIOp = OpInfo.MIOperandNo;
234 Operands.push_back(AsmWriterOperand(OpInfo.PrinterMethodName,
235 OpNo,
236 MIOp,
237 Modifier));
238 }
239 }
240 LastEmitted = VarEnd;
241 }
242 }
243
244 Operands.push_back(AsmWriterOperand("return;",
245 AsmWriterOperand::isLiteralStatementOperand));
246}
247
248/// MatchesAllButOneOp - If this instruction is exactly identical to the
249/// specified instruction except for one differing operand, return the differing
250/// operand number. If more than one operand mismatches, return ~1, otherwise
251/// if the instructions are identical return ~0.
252unsigned AsmWriterInst::MatchesAllButOneOp(const AsmWriterInst &Other)const{
253 if (Operands.size() != Other.Operands.size()) return ~1;
254
255 unsigned MismatchOperand = ~0U;
256 for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
257 if (Operands[i] != Other.Operands[i]) {
258 if (MismatchOperand != ~0U) // Already have one mismatch?
259 return ~1U;
260 else
261 MismatchOperand = i;
262 }
263 }
264 return MismatchOperand;
265}