1//===- yaml2goff - Convert YAML to a GOFF object file ---------------------===//
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/// \file
10/// The GOFF component of yaml2obj.
11///
12//===----------------------------------------------------------------------===//
13
14#include "llvm/ADT/IndexedMap.h"
15#include "llvm/ObjectYAML/ObjectYAML.h"
16#include "llvm/ObjectYAML/yaml2obj.h"
17#include "llvm/Support/ConvertEBCDIC.h"
18#include "llvm/Support/Endian.h"
19#include "llvm/Support/raw_ostream.h"
20
21using namespace llvm;
22
23namespace {
24
25// Common flag values on records.
26enum {
27 // Flag: This record is continued.
28 Rec_Continued = 1,
29
30 // Flag: This record is a continuation.
31 Rec_Continuation = 1 << (8 - 6 - 1),
32};
33
34template <typename ValueType> struct BinaryBeImpl {
35 ValueType Value;
36 BinaryBeImpl(ValueType V) : Value(V) {}
37};
38
39template <typename ValueType>
40raw_ostream &operator<<(raw_ostream &OS, const BinaryBeImpl<ValueType> &BBE) {
41 char Buffer[sizeof(BBE.Value)];
42 support::endian::write<ValueType, llvm::endianness::big, support::unaligned>(
43 Buffer, BBE.Value);
44 OS.write(Buffer, sizeof(BBE.Value));
45 return OS;
46}
47
48template <typename ValueType> BinaryBeImpl<ValueType> binaryBe(ValueType V) {
49 return BinaryBeImpl<ValueType>(V);
50}
51
52struct ZerosImpl {
53 size_t NumBytes;
54};
55
56raw_ostream &operator<<(raw_ostream &OS, const ZerosImpl &Z) {
57 OS.write_zeros(NumZeros: Z.NumBytes);
58 return OS;
59}
60
61ZerosImpl zeros(const size_t NumBytes) { return ZerosImpl{.NumBytes: NumBytes}; }
62
63// The GOFFOstream is responsible to write the data into the fixed physical
64// records of the format. A user of this class announces the start of a new
65// logical record and the size of its payload. While writing the payload, the
66// physical records are created for the data. Possible fill bytes at the end of
67// a physical record are written automatically.
68class GOFFOstream : public raw_ostream {
69public:
70 explicit GOFFOstream(raw_ostream &OS)
71 : OS(OS), LogicalRecords(0), RemainingSize(0), NewLogicalRecord(false) {
72 SetBufferSize(GOFF::PayloadLength);
73 }
74
75 ~GOFFOstream() { finalize(); }
76
77 void makeNewRecord(GOFF::RecordType Type, size_t Size) {
78 fillRecord();
79 CurrentType = Type;
80 RemainingSize = Size;
81 if (size_t Gap = (RemainingSize % GOFF::PayloadLength))
82 RemainingSize += GOFF::PayloadLength - Gap;
83 NewLogicalRecord = true;
84 ++LogicalRecords;
85 }
86
87 void finalize() { fillRecord(); }
88
89 uint32_t logicalRecords() { return LogicalRecords; }
90
91private:
92 // The underlying raw_ostream.
93 raw_ostream &OS;
94
95 // The number of logical records emitted so far.
96 uint32_t LogicalRecords;
97
98 // The remaining size of this logical record, including fill bytes.
99 size_t RemainingSize;
100
101 // The type of the current (logical) record.
102 GOFF::RecordType CurrentType;
103
104 // Signals start of new record.
105 bool NewLogicalRecord;
106
107 // Return the number of bytes left to write until next physical record.
108 // Please note that we maintain the total number of bytes left, not the
109 // written size.
110 size_t bytesToNextPhysicalRecord() {
111 size_t Bytes = RemainingSize % GOFF::PayloadLength;
112 return Bytes ? Bytes : GOFF::PayloadLength;
113 }
114
115 // Write the record prefix of a physical record, using the current record
116 // type.
117 static void writeRecordPrefix(raw_ostream &OS, GOFF::RecordType Type,
118 size_t RemainingSize,
119 uint8_t Flags = Rec_Continuation) {
120 uint8_t TypeAndFlags = Flags | (Type << 4);
121 if (RemainingSize > GOFF::RecordLength)
122 TypeAndFlags |= Rec_Continued;
123 OS << binaryBe(V: static_cast<unsigned char>(GOFF::PTVPrefix))
124 << binaryBe(V: static_cast<unsigned char>(TypeAndFlags))
125 << binaryBe(V: static_cast<unsigned char>(0));
126 }
127
128 // Fill the last physical record of a logical record with zero bytes.
129 void fillRecord() {
130 assert((GetNumBytesInBuffer() <= RemainingSize) &&
131 "More bytes in buffer than expected");
132 size_t Remains = RemainingSize - GetNumBytesInBuffer();
133 if (Remains) {
134 assert((Remains < GOFF::RecordLength) &&
135 "Attempting to fill more than one physical record");
136 raw_ostream::write_zeros(NumZeros: Remains);
137 }
138 flush();
139 assert(RemainingSize == 0 && "Not fully flushed");
140 assert(GetNumBytesInBuffer() == 0 && "Buffer not fully empty");
141 }
142
143 // See raw_ostream::write_impl.
144 void write_impl(const char *Ptr, size_t Size) override {
145 assert((RemainingSize >= Size) && "Attempt to write too much data");
146 assert(RemainingSize && "Logical record overflow");
147 if (!(RemainingSize % GOFF::PayloadLength)) {
148 writeRecordPrefix(OS, Type: CurrentType, RemainingSize,
149 Flags: NewLogicalRecord ? 0 : Rec_Continuation);
150 NewLogicalRecord = false;
151 }
152 assert(!NewLogicalRecord &&
153 "New logical record not on physical record boundary");
154
155 size_t Idx = 0;
156 while (Size > 0) {
157 size_t BytesToWrite = bytesToNextPhysicalRecord();
158 if (BytesToWrite > Size)
159 BytesToWrite = Size;
160 OS.write(Ptr: Ptr + Idx, Size: BytesToWrite);
161 Idx += BytesToWrite;
162 Size -= BytesToWrite;
163 RemainingSize -= BytesToWrite;
164 if (Size) {
165 writeRecordPrefix(OS, Type: CurrentType, RemainingSize);
166 }
167 }
168 }
169
170 // Return the current position within the stream, not counting the bytes
171 // currently in the buffer.
172 uint64_t current_pos() const override { return OS.tell(); }
173};
174
175class GOFFState {
176 void writeHeader(GOFFYAML::FileHeader &FileHdr);
177 void writeEnd();
178
179 void reportError(const Twine &Msg) {
180 ErrHandler(Msg);
181 HasError = true;
182 }
183
184 GOFFState(raw_ostream &OS, GOFFYAML::Object &Doc,
185 yaml::ErrorHandler ErrHandler)
186 : GW(OS), Doc(Doc), ErrHandler(ErrHandler), HasError(false) {}
187
188 ~GOFFState() { GW.finalize(); }
189
190 bool writeObject();
191
192public:
193 static bool writeGOFF(raw_ostream &OS, GOFFYAML::Object &Doc,
194 yaml::ErrorHandler ErrHandler);
195
196private:
197 GOFFOstream GW;
198 GOFFYAML::Object &Doc;
199 yaml::ErrorHandler ErrHandler;
200 bool HasError;
201};
202
203void GOFFState::writeHeader(GOFFYAML::FileHeader &FileHdr) {
204 SmallString<16> CCSIDName;
205 if (std::error_code EC =
206 ConverterEBCDIC::convertToEBCDIC(Source: FileHdr.CharacterSetName, Result&: CCSIDName))
207 reportError(Msg: "Conversion error on " + FileHdr.CharacterSetName);
208 if (CCSIDName.size() > 16) {
209 reportError(Msg: "CharacterSetName too long");
210 CCSIDName.resize(N: 16);
211 }
212 SmallString<16> LangProd;
213 if (std::error_code EC = ConverterEBCDIC::convertToEBCDIC(
214 Source: FileHdr.LanguageProductIdentifier, Result&: LangProd))
215 reportError(Msg: "Conversion error on " + FileHdr.LanguageProductIdentifier);
216 if (LangProd.size() > 16) {
217 reportError(Msg: "LanguageProductIdentifier too long");
218 LangProd.resize(N: 16);
219 }
220
221 GW.makeNewRecord(Type: GOFF::RT_HDR, Size: GOFF::PayloadLength);
222 GW << binaryBe(V: FileHdr.TargetEnvironment) // TargetEnvironment
223 << binaryBe(V: FileHdr.TargetOperatingSystem) // TargetOperatingSystem
224 << zeros(NumBytes: 2) // Reserved
225 << binaryBe(V: FileHdr.CCSID) // CCSID
226 << CCSIDName // CharacterSetName
227 << zeros(NumBytes: 16 - CCSIDName.size()) // Fill bytes
228 << LangProd // LanguageProductIdentifier
229 << zeros(NumBytes: 16 - LangProd.size()) // Fill bytes
230 << binaryBe(V: FileHdr.ArchitectureLevel); // ArchitectureLevel
231 // The module propties are optional. Figure out if we need to write them.
232 uint16_t ModPropLen = 0;
233 if (FileHdr.TargetSoftwareEnvironment)
234 ModPropLen = 3;
235 else if (FileHdr.InternalCCSID)
236 ModPropLen = 2;
237 if (ModPropLen) {
238 GW << binaryBe(V: ModPropLen) << zeros(NumBytes: 6);
239 if (ModPropLen >= 2)
240 GW << binaryBe(V: FileHdr.InternalCCSID ? *FileHdr.InternalCCSID : 0);
241 if (ModPropLen >= 3)
242 GW << binaryBe(V: FileHdr.TargetSoftwareEnvironment
243 ? *FileHdr.TargetSoftwareEnvironment
244 : 0);
245 }
246}
247
248void GOFFState::writeEnd() {
249 GW.makeNewRecord(Type: GOFF::RT_END, Size: GOFF::PayloadLength);
250 GW << binaryBe(V: uint8_t(0)) // No entry point
251 << binaryBe(V: uint8_t(0)) // No AMODE
252 << zeros(NumBytes: 3) // Reserved
253 << binaryBe(V: GW.logicalRecords());
254 // No entry point yet. Automatically fill remaining space with zero bytes.
255 GW.finalize();
256}
257
258bool GOFFState::writeObject() {
259 writeHeader(FileHdr&: Doc.Header);
260 if (HasError)
261 return false;
262 writeEnd();
263 return true;
264}
265
266bool GOFFState::writeGOFF(raw_ostream &OS, GOFFYAML::Object &Doc,
267 yaml::ErrorHandler ErrHandler) {
268 GOFFState State(OS, Doc, ErrHandler);
269 return State.writeObject();
270}
271} // namespace
272
273namespace llvm {
274namespace yaml {
275
276bool yaml2goff(llvm::GOFFYAML::Object &Doc, raw_ostream &Out,
277 ErrorHandler ErrHandler) {
278 return GOFFState::writeGOFF(OS&: Out, Doc, ErrHandler);
279}
280
281} // namespace yaml
282} // namespace llvm
283