1 //===- RemarkParser.cpp --------------------------------------------------===//
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 // This file provides utility methods used by clients that want to use the
10 // parser for remark diagnostics in LLVM.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Remarks/RemarkParser.h"
15 #include "BitstreamRemarkParser.h"
16 #include "YAMLRemarkParser.h"
17 #include "llvm-c/Remarks.h"
18 #include "llvm/Support/CBindingWrapping.h"
19 
20 using namespace llvm;
21 using namespace llvm::remarks;
22 
23 char EndOfFileError::ID = 0;
24 
25 ParsedStringTable::ParsedStringTable(StringRef InBuffer) : Buffer(InBuffer) {
26   while (!InBuffer.empty()) {
27     // Strings are separated by '\0' bytes.
28     std::pair<StringRef, StringRef> Split = InBuffer.split('\0');
29     // We only store the offset from the beginning of the buffer.
30     Offsets.push_back(Split.first.data() - Buffer.data());
31     InBuffer = Split.second;
32   }
33 }
34 
35 Expected<StringRef> ParsedStringTable::operator[](size_t Index) const {
36   if (Index >= Offsets.size())
37     return createStringError(
38         std::make_error_code(std::errc::invalid_argument),
39         "String with index %u is out of bounds (size = %u).", Index,
40         Offsets.size());
41 
42   size_t Offset = Offsets[Index];
43   // If it's the last offset, we can't use the next offset to know the size of
44   // the string.
45   size_t NextOffset =
46       (Index == Offsets.size() - 1) ? Buffer.size() : Offsets[Index + 1];
47   return StringRef(Buffer.data() + Offset, NextOffset - Offset - 1);
48 }
49 
50 Expected<std::unique_ptr<RemarkParser>>
51 llvm::remarks::createRemarkParser(Format ParserFormat, StringRef Buf) {
52   switch (ParserFormat) {
53   case Format::YAML:
54     return std::make_unique<YAMLRemarkParser>(Buf);
55   case Format::YAMLStrTab:
56     return createStringError(
57         std::make_error_code(std::errc::invalid_argument),
58         "The YAML with string table format requires a parsed string table.");
59   case Format::Bitstream:
60     return std::make_unique<BitstreamRemarkParser>(Buf);
61   case Format::Unknown:
62     return createStringError(std::make_error_code(std::errc::invalid_argument),
63                              "Unknown remark parser format.");
64   }
65   llvm_unreachable("unhandled ParseFormat");
66 }
67 
68 Expected<std::unique_ptr<RemarkParser>>
69 llvm::remarks::createRemarkParser(Format ParserFormat, StringRef Buf,
70                                   ParsedStringTable StrTab) {
71   switch (ParserFormat) {
72   case Format::YAML:
73     return createStringError(std::make_error_code(std::errc::invalid_argument),
74                              "The YAML format can't be used with a string "
75                              "table. Use yaml-strtab instead.");
76   case Format::YAMLStrTab:
77     return std::make_unique<YAMLStrTabRemarkParser>(Buf, std::move(StrTab));
78   case Format::Bitstream:
79     return std::make_unique<BitstreamRemarkParser>(Buf, std::move(StrTab));
80   case Format::Unknown:
81     return createStringError(std::make_error_code(std::errc::invalid_argument),
82                              "Unknown remark parser format.");
83   }
84   llvm_unreachable("unhandled ParseFormat");
85 }
86 
87 Expected<std::unique_ptr<RemarkParser>>
88 llvm::remarks::createRemarkParserFromMeta(
89     Format ParserFormat, StringRef Buf, Optional<ParsedStringTable> StrTab,
90     Optional<StringRef> ExternalFilePrependPath) {
91   switch (ParserFormat) {
92   // Depending on the metadata, the format can be either yaml or yaml-strtab,
93   // regardless of the input argument.
94   case Format::YAML:
95   case Format::YAMLStrTab:
96     return createYAMLParserFromMeta(Buf, std::move(StrTab),
97                                     std::move(ExternalFilePrependPath));
98   case Format::Bitstream:
99     return createBitstreamParserFromMeta(Buf, std::move(StrTab),
100                                          std::move(ExternalFilePrependPath));
101   case Format::Unknown:
102     return createStringError(std::make_error_code(std::errc::invalid_argument),
103                              "Unknown remark parser format.");
104   }
105   llvm_unreachable("unhandled ParseFormat");
106 }
107 
108 namespace {
109 // Wrapper that holds the state needed to interact with the C API.
110 struct CParser {
111   std::unique_ptr<RemarkParser> TheParser;
112   Optional<std::string> Err;
113 
114   CParser(Format ParserFormat, StringRef Buf,
115           Optional<ParsedStringTable> StrTab = None)
116       : TheParser(cantFail(
117             StrTab ? createRemarkParser(ParserFormat, Buf, std::move(*StrTab))
118                    : createRemarkParser(ParserFormat, Buf))) {}
119 
120   void handleError(Error E) { Err.emplace(toString(std::move(E))); }
121   bool hasError() const { return Err.hasValue(); }
122   const char *getMessage() const { return Err ? Err->c_str() : nullptr; };
123 };
124 } // namespace
125 
126 // Create wrappers for C Binding types (see CBindingWrapping.h).
127 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(CParser, LLVMRemarkParserRef)
128 
129 extern "C" LLVMRemarkParserRef LLVMRemarkParserCreateYAML(const void *Buf,
130                                                           uint64_t Size) {
131   return wrap(new CParser(Format::YAML,
132                           StringRef(static_cast<const char *>(Buf), Size)));
133 }
134 
135 extern "C" LLVMRemarkParserRef LLVMRemarkParserCreateBitstream(const void *Buf,
136                                                                uint64_t Size) {
137   return wrap(new CParser(Format::Bitstream,
138                           StringRef(static_cast<const char *>(Buf), Size)));
139 }
140 
141 extern "C" LLVMRemarkEntryRef
142 LLVMRemarkParserGetNext(LLVMRemarkParserRef Parser) {
143   CParser &TheCParser = *unwrap(Parser);
144   remarks::RemarkParser &TheParser = *TheCParser.TheParser;
145 
146   Expected<std::unique_ptr<Remark>> MaybeRemark = TheParser.next();
147   if (Error E = MaybeRemark.takeError()) {
148     if (E.isA<EndOfFileError>()) {
149       consumeError(std::move(E));
150       return nullptr;
151     }
152 
153     // Handle the error. Allow it to be checked through HasError and
154     // GetErrorMessage.
155     TheCParser.handleError(std::move(E));
156     return nullptr;
157   }
158 
159   // Valid remark.
160   return wrap(MaybeRemark->release());
161 }
162 
163 extern "C" LLVMBool LLVMRemarkParserHasError(LLVMRemarkParserRef Parser) {
164   return unwrap(Parser)->hasError();
165 }
166 
167 extern "C" const char *
168 LLVMRemarkParserGetErrorMessage(LLVMRemarkParserRef Parser) {
169   return unwrap(Parser)->getMessage();
170 }
171 
172 extern "C" void LLVMRemarkParserDispose(LLVMRemarkParserRef Parser) {
173   delete unwrap(Parser);
174 }
175