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 "YAMLRemarkParser.h"
16 #include "llvm-c/Remarks.h"
17 #include "llvm/ADT/STLExtras.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 llvm::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 createStringError(std::make_error_code(std::errc::invalid_argument),
61                              "Parsing bitstream remarks is not supported.");
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 llvm::make_unique<YAMLStrTabRemarkParser>(Buf, std::move(StrTab));
79   case Format::Bitstream:
80     return createStringError(std::make_error_code(std::errc::invalid_argument),
81                              "Parsing bitstream remarks is not supported.");
82   case Format::Unknown:
83     return createStringError(std::make_error_code(std::errc::invalid_argument),
84                              "Unknown remark parser format.");
85   }
86   llvm_unreachable("unhandled ParseFormat");
87 }
88 
89 Expected<std::unique_ptr<RemarkParser>>
90 llvm::remarks::createRemarkParserFromMeta(Format ParserFormat, StringRef Buf,
91                                           Optional<ParsedStringTable> StrTab) {
92   switch (ParserFormat) {
93   // Depending on the metadata, the format can be either yaml or yaml-strtab,
94   // regardless of the input argument.
95   case Format::YAML:
96   case Format::YAMLStrTab:
97     return createYAMLParserFromMeta(Buf, std::move(StrTab));
98   case Format::Bitstream:
99     return createStringError(std::make_error_code(std::errc::invalid_argument),
100                              "Parsing bitstream remarks is not supported.");
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 // Wrapper that holds the state needed to interact with the C API.
109 struct CParser {
110   std::unique_ptr<RemarkParser> TheParser;
111   Optional<std::string> Err;
112 
113   CParser(Format ParserFormat, StringRef Buf,
114           Optional<ParsedStringTable> StrTab = None)
115       : TheParser(cantFail(
116             StrTab ? createRemarkParser(ParserFormat, Buf, std::move(*StrTab))
117                    : createRemarkParser(ParserFormat, Buf))) {}
118 
119   void handleError(Error E) { Err.emplace(toString(std::move(E))); }
120   bool hasError() const { return Err.hasValue(); }
121   const char *getMessage() const { return Err ? Err->c_str() : nullptr; };
122 };
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" LLVMRemarkEntryRef
134 LLVMRemarkParserGetNext(LLVMRemarkParserRef Parser) {
135   CParser &TheCParser = *unwrap(Parser);
136   remarks::RemarkParser &TheParser = *TheCParser.TheParser;
137 
138   Expected<std::unique_ptr<Remark>> MaybeRemark = TheParser.next();
139   if (Error E = MaybeRemark.takeError()) {
140     if (E.isA<EndOfFileError>()) {
141       consumeError(std::move(E));
142       return nullptr;
143     }
144 
145     // Handle the error. Allow it to be checked through HasError and
146     // GetErrorMessage.
147     TheCParser.handleError(std::move(E));
148     return nullptr;
149   }
150 
151   // Valid remark.
152   return wrap(MaybeRemark->release());
153 }
154 
155 extern "C" LLVMBool LLVMRemarkParserHasError(LLVMRemarkParserRef Parser) {
156   return unwrap(Parser)->hasError();
157 }
158 
159 extern "C" const char *
160 LLVMRemarkParserGetErrorMessage(LLVMRemarkParserRef Parser) {
161   return unwrap(Parser)->getMessage();
162 }
163 
164 extern "C" void LLVMRemarkParserDispose(LLVMRemarkParserRef Parser) {
165   delete unwrap(Parser);
166 }
167