1 //===--- Diagnostics.cpp - Helper class for error diagnostics ---*- C++ -*-===//
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 #include "clang/ASTMatchers/Dynamic/Diagnostics.h"
10 
11 namespace clang {
12 namespace ast_matchers {
13 namespace dynamic {
14 Diagnostics::ArgStream Diagnostics::pushContextFrame(ContextType Type,
15                                                      SourceRange Range) {
16   ContextStack.emplace_back();
17   ContextFrame& data = ContextStack.back();
18   data.Type = Type;
19   data.Range = Range;
20   return ArgStream(&data.Args);
21 }
22 
23 Diagnostics::Context::Context(ConstructMatcherEnum, Diagnostics *Error,
24                               StringRef MatcherName,
25                               SourceRange MatcherRange)
26     : Error(Error) {
27   Error->pushContextFrame(CT_MatcherConstruct, MatcherRange) << MatcherName;
28 }
29 
30 Diagnostics::Context::Context(MatcherArgEnum, Diagnostics *Error,
31                               StringRef MatcherName,
32                               SourceRange MatcherRange,
33                               unsigned ArgNumber)
34     : Error(Error) {
35   Error->pushContextFrame(CT_MatcherArg, MatcherRange) << ArgNumber
36                                                        << MatcherName;
37 }
38 
39 Diagnostics::Context::~Context() { Error->ContextStack.pop_back(); }
40 
41 Diagnostics::OverloadContext::OverloadContext(Diagnostics *Error)
42     : Error(Error), BeginIndex(Error->Errors.size()) {}
43 
44 Diagnostics::OverloadContext::~OverloadContext() {
45   // Merge all errors that happened while in this context.
46   if (BeginIndex < Error->Errors.size()) {
47     Diagnostics::ErrorContent &Dest = Error->Errors[BeginIndex];
48     for (size_t i = BeginIndex + 1, e = Error->Errors.size(); i < e; ++i) {
49       Dest.Messages.push_back(Error->Errors[i].Messages[0]);
50     }
51     Error->Errors.resize(BeginIndex + 1);
52   }
53 }
54 
55 void Diagnostics::OverloadContext::revertErrors() {
56   // Revert the errors.
57   Error->Errors.resize(BeginIndex);
58 }
59 
60 Diagnostics::ArgStream &Diagnostics::ArgStream::operator<<(const Twine &Arg) {
61   Out->push_back(Arg.str());
62   return *this;
63 }
64 
65 Diagnostics::ArgStream Diagnostics::addError(SourceRange Range,
66                                              ErrorType Error) {
67   Errors.emplace_back();
68   ErrorContent &Last = Errors.back();
69   Last.ContextStack = ContextStack;
70   Last.Messages.emplace_back();
71   Last.Messages.back().Range = Range;
72   Last.Messages.back().Type = Error;
73   return ArgStream(&Last.Messages.back().Args);
74 }
75 
76 static StringRef contextTypeToFormatString(Diagnostics::ContextType Type) {
77   switch (Type) {
78     case Diagnostics::CT_MatcherConstruct:
79       return "Error building matcher $0.";
80     case Diagnostics::CT_MatcherArg:
81       return "Error parsing argument $0 for matcher $1.";
82   }
83   llvm_unreachable("Unknown ContextType value.");
84 }
85 
86 static StringRef errorTypeToFormatString(Diagnostics::ErrorType Type) {
87   switch (Type) {
88   case Diagnostics::ET_RegistryMatcherNotFound:
89     return "Matcher not found: $0";
90   case Diagnostics::ET_RegistryWrongArgCount:
91     return "Incorrect argument count. (Expected = $0) != (Actual = $1)";
92   case Diagnostics::ET_RegistryWrongArgType:
93     return "Incorrect type for arg $0. (Expected = $1) != (Actual = $2)";
94   case Diagnostics::ET_RegistryNotBindable:
95     return "Matcher does not support binding.";
96   case Diagnostics::ET_RegistryAmbiguousOverload:
97     // TODO: Add type info about the overload error.
98     return "Ambiguous matcher overload.";
99   case Diagnostics::ET_RegistryValueNotFound:
100     return "Value not found: $0";
101   case Diagnostics::ET_RegistryUnknownEnumWithReplace:
102     return "Unknown value '$1' for arg $0; did you mean '$2'";
103 
104   case Diagnostics::ET_ParserStringError:
105     return "Error parsing string token: <$0>";
106   case Diagnostics::ET_ParserNoOpenParen:
107     return "Error parsing matcher. Found token <$0> while looking for '('.";
108   case Diagnostics::ET_ParserNoCloseParen:
109     return "Error parsing matcher. Found end-of-code while looking for ')'.";
110   case Diagnostics::ET_ParserNoComma:
111     return "Error parsing matcher. Found token <$0> while looking for ','.";
112   case Diagnostics::ET_ParserNoCode:
113     return "End of code found while looking for token.";
114   case Diagnostics::ET_ParserNotAMatcher:
115     return "Input value is not a matcher expression.";
116   case Diagnostics::ET_ParserInvalidToken:
117     return "Invalid token <$0> found when looking for a value.";
118   case Diagnostics::ET_ParserMalformedBindExpr:
119     return "Malformed bind() expression.";
120   case Diagnostics::ET_ParserTrailingCode:
121     return "Expected end of code.";
122   case Diagnostics::ET_ParserNumberError:
123     return "Error parsing numeric literal: <$0>";
124   case Diagnostics::ET_ParserOverloadedType:
125     return "Input value has unresolved overloaded type: $0";
126 
127   case Diagnostics::ET_None:
128     return "<N/A>";
129   }
130   llvm_unreachable("Unknown ErrorType value.");
131 }
132 
133 static void formatErrorString(StringRef FormatString,
134                               ArrayRef<std::string> Args,
135                               llvm::raw_ostream &OS) {
136   while (!FormatString.empty()) {
137     std::pair<StringRef, StringRef> Pieces = FormatString.split("$");
138     OS << Pieces.first.str();
139     if (Pieces.second.empty()) break;
140 
141     const char Next = Pieces.second.front();
142     FormatString = Pieces.second.drop_front();
143     if (Next >= '0' && Next <= '9') {
144       const unsigned Index = Next - '0';
145       if (Index < Args.size()) {
146         OS << Args[Index];
147       } else {
148         OS << "<Argument_Not_Provided>";
149       }
150     }
151   }
152 }
153 
154 static void maybeAddLineAndColumn(SourceRange Range,
155                                   llvm::raw_ostream &OS) {
156   if (Range.Start.Line > 0 && Range.Start.Column > 0) {
157     OS << Range.Start.Line << ":" << Range.Start.Column << ": ";
158   }
159 }
160 
161 static void printContextFrameToStream(const Diagnostics::ContextFrame &Frame,
162                                       llvm::raw_ostream &OS) {
163   maybeAddLineAndColumn(Frame.Range, OS);
164   formatErrorString(contextTypeToFormatString(Frame.Type), Frame.Args, OS);
165 }
166 
167 static void
168 printMessageToStream(const Diagnostics::ErrorContent::Message &Message,
169                      const Twine Prefix, llvm::raw_ostream &OS) {
170   maybeAddLineAndColumn(Message.Range, OS);
171   OS << Prefix;
172   formatErrorString(errorTypeToFormatString(Message.Type), Message.Args, OS);
173 }
174 
175 static void printErrorContentToStream(const Diagnostics::ErrorContent &Content,
176                                       llvm::raw_ostream &OS) {
177   if (Content.Messages.size() == 1) {
178     printMessageToStream(Content.Messages[0], "", OS);
179   } else {
180     for (size_t i = 0, e = Content.Messages.size(); i != e; ++i) {
181       if (i != 0) OS << "\n";
182       printMessageToStream(Content.Messages[i],
183                            "Candidate " + Twine(i + 1) + ": ", OS);
184     }
185   }
186 }
187 
188 void Diagnostics::printToStream(llvm::raw_ostream &OS) const {
189   for (size_t i = 0, e = Errors.size(); i != e; ++i) {
190     if (i != 0) OS << "\n";
191     printErrorContentToStream(Errors[i], OS);
192   }
193 }
194 
195 std::string Diagnostics::toString() const {
196   std::string S;
197   llvm::raw_string_ostream OS(S);
198   printToStream(OS);
199   return OS.str();
200 }
201 
202 void Diagnostics::printToStreamFull(llvm::raw_ostream &OS) const {
203   for (size_t i = 0, e = Errors.size(); i != e; ++i) {
204     if (i != 0) OS << "\n";
205     const ErrorContent &Error = Errors[i];
206     for (size_t i = 0, e = Error.ContextStack.size(); i != e; ++i) {
207       printContextFrameToStream(Error.ContextStack[i], OS);
208       OS << "\n";
209     }
210     printErrorContentToStream(Error, OS);
211   }
212 }
213 
214 std::string Diagnostics::toStringFull() const {
215   std::string S;
216   llvm::raw_string_ostream OS(S);
217   printToStreamFull(OS);
218   return OS.str();
219 }
220 
221 }  // namespace dynamic
222 }  // namespace ast_matchers
223 }  // namespace clang
224