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