xref: /llvm-project/llvm/tools/llvm-rc/ResourceScriptParser.h (revision 72aa937ed8cf9a0478bc9908f80ce51e372e8ef4)
1 //===-- ResourceScriptParser.h ----------------------------------*- C++-*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===---------------------------------------------------------------------===//
9 //
10 // This defines the RC scripts parser. It takes a sequence of RC tokens
11 // and then provides the method to parse the resources one by one.
12 //
13 //===---------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TOOLS_LLVMRC_RESOURCESCRIPTPARSER_H
16 #define LLVM_TOOLS_LLVMRC_RESOURCESCRIPTPARSER_H
17 
18 #include "ResourceScriptStmt.h"
19 #include "ResourceScriptToken.h"
20 
21 #include "llvm/Support/Compiler.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 #include <system_error>
25 #include <vector>
26 
27 namespace llvm {
28 namespace rc {
29 
30 class RCParser {
31 public:
32   using LocIter = std::vector<RCToken>::iterator;
33   using ParseType = Expected<std::unique_ptr<RCResource>>;
34   using ParseOptionType = Expected<std::unique_ptr<OptionalStmt>>;
35 
36   // Class describing a single failure of parser.
37   class ParserError : public ErrorInfo<ParserError> {
38   public:
39     ParserError(Twine Expected, const LocIter CurLoc, const LocIter End);
40 
41     void log(raw_ostream &OS) const override { OS << CurMessage; }
42     std::error_code convertToErrorCode() const override {
43       return std::make_error_code(std::errc::invalid_argument);
44     }
45     const std::string &getMessage() const { return CurMessage; }
46 
47     static char ID; // Keep llvm::Error happy.
48 
49   private:
50     std::string CurMessage;
51     LocIter ErrorLoc, FileEnd;
52   };
53 
54   RCParser(const std::vector<RCToken> &TokenList);
55   RCParser(std::vector<RCToken> &&TokenList);
56 
57   // Reads and returns a single resource definition, or error message if any
58   // occurred.
59   ParseType parseSingleResource();
60 
61   bool isEof() const;
62 
63 private:
64   using Kind = RCToken::Kind;
65 
66   // Checks if the current parser state points to the token of type TokenKind.
67   bool isNextTokenKind(Kind TokenKind) const;
68 
69   // These methods assume that the parser is not in EOF state.
70 
71   // Take a look at the current token. Do not fetch it.
72   const RCToken &look() const;
73   // Read the current token and advance the state by one token.
74   const RCToken &read();
75   // Advance the state by one token, discarding the current token.
76   void consume();
77 
78   // The following methods try to read a single token, check if it has the
79   // correct type and then parse it.
80   Expected<uint32_t> readInt();           // Parse an integer.
81   Expected<StringRef> readString();       // Parse a string.
82   Expected<StringRef> readIdentifier();   // Parse an identifier.
83   Expected<IntOrString> readTypeOrName(); // Parse an integer or an identifier.
84 
85   // Advance the state by one, discarding the current token.
86   // If the discarded token had an incorrect type, fail.
87   Error consumeType(Kind TokenKind);
88 
89   // Check the current token type. If it's TokenKind, discard it.
90   // Return true if the parser consumed this token successfully.
91   bool consumeOptionalType(Kind TokenKind);
92 
93   // Read at least MinCount, and at most MaxCount integers separated by
94   // commas. The parser stops reading after fetching MaxCount integers
95   // or after an error occurs. Whenever the parser reads a comma, it
96   // expects an integer to follow.
97   Expected<SmallVector<uint32_t, 8>> readIntsWithCommas(size_t MinCount,
98                                                         size_t MaxCount);
99 
100   // Reads a set of optional statements. These can change the behavior of
101   // a number of resource types (e.g. STRINGTABLE, MENU or DIALOG) if provided
102   // before the main block with the contents of the resource.
103   // Usually, resources use a basic set of optional statements:
104   //    CHARACTERISTICS, LANGUAGE, VERSION
105   // However, DIALOG and DIALOGEX extend this list by the following items:
106   //    CAPTION, CLASS, EXSTYLE, FONT, MENU, STYLE
107   // UseExtendedStatements flag (off by default) allows the parser to read
108   // the additional types of statements.
109   //
110   // Ref (to the list of all optional statements):
111   //    msdn.microsoft.com/en-us/library/windows/desktop/aa381002(v=vs.85).aspx
112   Expected<OptionalStmtList>
113   parseOptionalStatements(bool UseExtendedStatements = false);
114 
115   // Read a single optional statement.
116   Expected<std::unique_ptr<OptionalStmt>>
117   parseSingleOptionalStatement(bool UseExtendedStatements = false);
118 
119   // Top-level resource parsers.
120   ParseType parseLanguageResource();
121   ParseType parseCursorResource();
122   ParseType parseIconResource();
123   ParseType parseHTMLResource();
124   ParseType parseStringTableResource();
125 
126   // Optional statement parsers.
127   ParseOptionType parseLanguageStmt();
128   ParseOptionType parseCharacteristicsStmt();
129   ParseOptionType parseVersionStmt();
130 
131   // Raises an error. If IsAlreadyRead = false (default), this complains about
132   // the token that couldn't be parsed. If the flag is on, this complains about
133   // the correctly read token that makes no sense (that is, the current parser
134   // state is beyond the erroneous token.)
135   Error getExpectedError(const Twine Message, bool IsAlreadyRead = false);
136 
137   std::vector<RCToken> Tokens;
138   LocIter CurLoc;
139   const LocIter End;
140 };
141 
142 } // namespace rc
143 } // namespace llvm
144 
145 #endif
146