PreprocessorLexer.h source code [clang_source_code/include/clang/Lex/PreprocessorLexer.h]

1	//===- PreprocessorLexer.h - C Language Family Lexer ------------- 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	/// \file
10	/// Defines the PreprocessorLexer interface.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#ifndef LLVM_CLANG_LEX_PREPROCESSORLEXER_H
15	#define LLVM_CLANG_LEX_PREPROCESSORLEXER_H
16
17	#include "clang/Lex/MultipleIncludeOpt.h"
18	#include "clang/Lex/Token.h"
19	#include "clang/Basic/SourceLocation.h"
20	#include "llvm/ADT/ArrayRef.h"
21	#include "llvm/ADT/SmallVector.h"
22	#include <cassert>
23
24	namespace clang {
25
26	class FileEntry;
27	class Preprocessor;
28
29	class PreprocessorLexer {
30	virtual void anchor();
31
32	protected:
33	friend class Preprocessor;
34
35	// Preprocessor object controlling lexing.
36	Preprocessor *PP = nullptr;
37
38	/// The SourceManager FileID corresponding to the file being lexed.
39	const FileID FID;
40
41	/// Number of SLocEntries before lexing the file.
42	unsigned InitialNumSLocEntries = 0;
43
44	//===--------------------------------------------------------------------===//
45	// Context-specific lexing flags set by the preprocessor.
46	//===--------------------------------------------------------------------===//
47
48	/// True when parsing \#XXX; turns '\\n' into a tok::eod token.
49	bool ParsingPreprocessorDirective = false;
50
51	/// True after \#include; turns \<xx> or "xxx" into a tok::header_name token.
52	bool ParsingFilename = false;
53
54	/// True if in raw mode.
55	///
56	/// Raw mode disables interpretation of tokens and is a far faster mode to
57	/// lex in than non-raw-mode. This flag:
58	/// 1. If EOF of the current lexer is found, the include stack isn't popped.
59	/// 2. Identifier information is not looked up for identifier tokens. As an
60	/// effect of this, implicit macro expansion is naturally disabled.
61	/// 3. "#" tokens at the start of a line are treated as normal tokens, not
62	/// implicitly transformed by the lexer.
63	/// 4. All diagnostic messages are disabled.
64	/// 5. No callbacks are made into the preprocessor.
65	///
66	/// Note that in raw mode that the PP pointer may be null.
67	bool LexingRawMode = false;
68
69	/// A state machine that detects the \#ifndef-wrapping a file
70	/// idiom for the multiple-include optimization.
71	MultipleIncludeOpt MIOpt;
72
73	/// Information about the set of \#if/\#ifdef/\#ifndef blocks
74	/// we are currently in.
75	SmallVector<PPConditionalInfo, 4> ConditionalStack;
76
77	PreprocessorLexer() : FID() {}
78	PreprocessorLexer(Preprocessor *pp, FileID fid);
79	virtual ~PreprocessorLexer() = default;
80
81	virtual void IndirectLex(Token& Result) = 0;
82
83	/// Return the source location for the next observable location.
84	virtual SourceLocation getSourceLocation() = 0;
85
86	//===--------------------------------------------------------------------===//
87	// #if directive handling.
88
89	/// pushConditionalLevel - When we enter a \#if directive, this keeps track of
90	/// what we are currently in for diagnostic emission (e.g. \#if with missing
91	/// \#endif).
92	void pushConditionalLevel(SourceLocation DirectiveStart, bool WasSkipping,
93	bool FoundNonSkip, bool FoundElse) {
94	PPConditionalInfo CI;
95	CI.IfLoc = DirectiveStart;
96	CI.WasSkipping = WasSkipping;
97	CI.FoundNonSkip = FoundNonSkip;
98	CI.FoundElse = FoundElse;
99	ConditionalStack.push_back(CI);
100	}
101	void pushConditionalLevel(const PPConditionalInfo &CI) {
102	ConditionalStack.push_back(CI);
103	}
104
105	/// popConditionalLevel - Remove an entry off the top of the conditional
106	/// stack, returning information about it. If the conditional stack is empty,
107	/// this returns true and does not fill in the arguments.
108	bool popConditionalLevel(PPConditionalInfo &CI) {
109	if (ConditionalStack.empty())
110	return true;
111	CI = ConditionalStack.pop_back_val();
112	return false;
113	}
114
115	/// Return the top of the conditional stack.
116	/// \pre This requires that there be a conditional active.
117	PPConditionalInfo &peekConditionalLevel() {
118	(0) . __assert_fail ("!ConditionalStack.empty() && \"No conditionals active!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/PreprocessorLexer.h", 118, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!ConditionalStack.empty() && "No conditionals active!");
119	return ConditionalStack.back();
120	}
121
122	unsigned getConditionalStackDepth() const { return ConditionalStack.size(); }
123
124	public:
125	PreprocessorLexer(const PreprocessorLexer &) = delete;
126	PreprocessorLexer &operator=(const PreprocessorLexer &) = delete;
127
128	//===--------------------------------------------------------------------===//
129	// Misc. lexing methods.
130
131	/// Lex a token, producing a header-name token if possible.
132	void LexIncludeFilename(Token &FilenameTok);
133
134	/// Inform the lexer whether or not we are currently lexing a
135	/// preprocessor directive.
136	void setParsingPreprocessorDirective(bool f) {
137	ParsingPreprocessorDirective = f;
138	}
139
140	/// Return true if this lexer is in raw mode or not.
141	bool isLexingRawMode() const { return LexingRawMode; }
142
143	/// Return the preprocessor object for this lexer.
144	Preprocessor *getPP() const { return PP; }
145
146	FileID getFileID() const {
147	(0) . __assert_fail ("PP && \"PreprocessorLexer..getFileID() should only be used with a Preprocessor\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/PreprocessorLexer.h", 148, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(PP &&
148	(0) . __assert_fail ("PP && \"PreprocessorLexer..getFileID() should only be used with a Preprocessor\"", "/home/seafit/code_projects/clang_source/clang/include/clang/Lex/PreprocessorLexer.h", 148, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true"> "PreprocessorLexer::getFileID() should only be used with a Preprocessor");
149	return FID;
150	}
151
152	/// Number of SLocEntries before lexing the file.
153	unsigned getInitialNumSLocEntries() const {
154	return InitialNumSLocEntries;
155	}
156
157	/// getFileEntry - Return the FileEntry corresponding to this FileID. Like
158	/// getFileID(), this only works for lexers with attached preprocessors.
159	const FileEntry *getFileEntry() const;
160
161	/// Iterator that traverses the current stack of preprocessor
162	/// conditional directives (\#if/\#ifdef/\#ifndef).
163	using conditional_iterator =
164	SmallVectorImpl<PPConditionalInfo>::const_iterator;
165
166	conditional_iterator conditional_begin() const {
167	return ConditionalStack.begin();
168	}
169
170	conditional_iterator conditional_end() const {
171	return ConditionalStack.end();
172	}
173
174	void setConditionalLevels(ArrayRef<PPConditionalInfo> CL) {
175	ConditionalStack.clear();
176	ConditionalStack.append(CL.begin(), CL.end());
177	}
178	};
179
180	} // namespace clang
181
182	#endif // LLVM_CLANG_LEX_PREPROCESSORLEXER_H
183