1//===--- PrettyPrinter.h - Classes for aiding with AST printing -*- 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// This file defines helper types for AST pretty-printing.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_PRETTYPRINTER_H
14#define LLVM_CLANG_AST_PRETTYPRINTER_H
15
16#include "clang/Basic/LLVM.h"
17#include "clang/Basic/LangOptions.h"
18
19namespace clang {
20
21class DeclContext;
22class LangOptions;
23class Stmt;
24
25class PrinterHelper {
26public:
27 virtual ~PrinterHelper();
28 virtual bool handledStmt(Stmt* E, raw_ostream& OS) = 0;
29};
30
31/// Callbacks to use to customize the behavior of the pretty-printer.
32class PrintingCallbacks {
33protected:
34 ~PrintingCallbacks() = default;
35
36public:
37 /// Remap a path to a form suitable for printing.
38 virtual std::string remapPath(StringRef Path) const {
39 return std::string(Path);
40 }
41
42 /// When printing type to be inserted into code in specific context, this
43 /// callback can be used to avoid printing the redundant part of the
44 /// qualifier. For example, when inserting code inside namespace foo, we
45 /// should print bar::SomeType instead of foo::bar::SomeType.
46 /// To do this, shouldPrintScope should return true on "foo" NamespaceDecl.
47 /// The printing stops at the first isScopeVisible() == true, so there will
48 /// be no calls with outer scopes.
49 virtual bool isScopeVisible(const DeclContext *DC) const { return false; }
50};
51
52/// Describes how types, statements, expressions, and declarations should be
53/// printed.
54///
55/// This type is intended to be small and suitable for passing by value.
56/// It is very frequently copied.
57struct PrintingPolicy {
58 /// Create a default printing policy for the specified language.
59 PrintingPolicy(const LangOptions &LO)
60 : Indentation(2), SuppressSpecifiers(false),
61 SuppressTagKeyword(LO.CPlusPlus), IncludeTagDefinition(false),
62 SuppressScope(false), SuppressUnwrittenScope(false),
63 SuppressInlineNamespace(true), SuppressElaboration(false),
64 SuppressInitializers(false), ConstantArraySizeAsWritten(false),
65 AnonymousTagLocations(true), SuppressStrongLifetime(false),
66 SuppressLifetimeQualifiers(false),
67 SuppressTemplateArgsInCXXConstructors(false),
68 SuppressDefaultTemplateArgs(true), Bool(LO.Bool),
69 Nullptr(LO.CPlusPlus11 || LO.C23), NullptrTypeInNamespace(LO.CPlusPlus),
70 Restrict(LO.C99), Alignof(LO.CPlusPlus11), UnderscoreAlignof(LO.C11),
71 UseVoidForZeroParams(!LO.CPlusPlus),
72 SplitTemplateClosers(!LO.CPlusPlus11), TerseOutput(false),
73 PolishForDeclaration(false), Half(LO.Half),
74 MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
75 MSVCFormatting(false), ConstantsAsWritten(false),
76 SuppressImplicitBase(false), FullyQualifiedName(false),
77 PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true),
78 UsePreferredNames(true), AlwaysIncludeTypeForTemplateArgument(false),
79 CleanUglifiedParameters(false), EntireContentsOfLargeArray(true),
80 UseEnumerators(true) {}
81
82 /// Adjust this printing policy for cases where it's known that we're
83 /// printing C++ code (for instance, if AST dumping reaches a C++-only
84 /// construct). This should not be used if a real LangOptions object is
85 /// available.
86 void adjustForCPlusPlus() {
87 SuppressTagKeyword = true;
88 Bool = true;
89 UseVoidForZeroParams = false;
90 }
91
92 /// The number of spaces to use to indent each line.
93 unsigned Indentation : 8;
94
95 /// Whether we should suppress printing of the actual specifiers for
96 /// the given type or declaration.
97 ///
98 /// This flag is only used when we are printing declarators beyond
99 /// the first declarator within a declaration group. For example, given:
100 ///
101 /// \code
102 /// const int *x, *y;
103 /// \endcode
104 ///
105 /// SuppressSpecifiers will be false when printing the
106 /// declaration for "x", so that we will print "int *x"; it will be
107 /// \c true when we print "y", so that we suppress printing the
108 /// "const int" type specifier and instead only print the "*y".
109 LLVM_PREFERRED_TYPE(bool)
110 unsigned SuppressSpecifiers : 1;
111
112 /// Whether type printing should skip printing the tag keyword.
113 ///
114 /// This is used when printing the inner type of elaborated types,
115 /// (as the tag keyword is part of the elaborated type):
116 ///
117 /// \code
118 /// struct Geometry::Point;
119 /// \endcode
120 LLVM_PREFERRED_TYPE(bool)
121 unsigned SuppressTagKeyword : 1;
122
123 /// When true, include the body of a tag definition.
124 ///
125 /// This is used to place the definition of a struct
126 /// in the middle of another declaration as with:
127 ///
128 /// \code
129 /// typedef struct { int x, y; } Point;
130 /// \endcode
131 LLVM_PREFERRED_TYPE(bool)
132 unsigned IncludeTagDefinition : 1;
133
134 /// Suppresses printing of scope specifiers.
135 LLVM_PREFERRED_TYPE(bool)
136 unsigned SuppressScope : 1;
137
138 /// Suppress printing parts of scope specifiers that are never
139 /// written, e.g., for anonymous namespaces.
140 LLVM_PREFERRED_TYPE(bool)
141 unsigned SuppressUnwrittenScope : 1;
142
143 /// Suppress printing parts of scope specifiers that correspond
144 /// to inline namespaces, where the name is unambiguous with the specifier
145 /// removed.
146 LLVM_PREFERRED_TYPE(bool)
147 unsigned SuppressInlineNamespace : 1;
148
149 /// Ignore qualifiers and tag keywords as specified by elaborated type sugar,
150 /// instead letting the underlying type print as normal.
151 LLVM_PREFERRED_TYPE(bool)
152 unsigned SuppressElaboration : 1;
153
154 /// Suppress printing of variable initializers.
155 ///
156 /// This flag is used when printing the loop variable in a for-range
157 /// statement. For example, given:
158 ///
159 /// \code
160 /// for (auto x : coll)
161 /// \endcode
162 ///
163 /// SuppressInitializers will be true when printing "auto x", so that the
164 /// internal initializer constructed for x will not be printed.
165 LLVM_PREFERRED_TYPE(bool)
166 unsigned SuppressInitializers : 1;
167
168 /// Whether we should print the sizes of constant array expressions as written
169 /// in the sources.
170 ///
171 /// This flag determines whether array types declared as
172 ///
173 /// \code
174 /// int a[4+10*10];
175 /// char a[] = "A string";
176 /// \endcode
177 ///
178 /// will be printed as written or as follows:
179 ///
180 /// \code
181 /// int a[104];
182 /// char a[9] = "A string";
183 /// \endcode
184 LLVM_PREFERRED_TYPE(bool)
185 unsigned ConstantArraySizeAsWritten : 1;
186
187 /// When printing an anonymous tag name, also print the location of that
188 /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints
189 /// "(anonymous)" for the name.
190 LLVM_PREFERRED_TYPE(bool)
191 unsigned AnonymousTagLocations : 1;
192
193 /// When true, suppress printing of the __strong lifetime qualifier in ARC.
194 LLVM_PREFERRED_TYPE(bool)
195 unsigned SuppressStrongLifetime : 1;
196
197 /// When true, suppress printing of lifetime qualifier in ARC.
198 LLVM_PREFERRED_TYPE(bool)
199 unsigned SuppressLifetimeQualifiers : 1;
200
201 /// When true, suppresses printing template arguments in names of C++
202 /// constructors.
203 LLVM_PREFERRED_TYPE(bool)
204 unsigned SuppressTemplateArgsInCXXConstructors : 1;
205
206 /// When true, attempt to suppress template arguments that match the default
207 /// argument for the parameter.
208 LLVM_PREFERRED_TYPE(bool)
209 unsigned SuppressDefaultTemplateArgs : 1;
210
211 /// Whether we can use 'bool' rather than '_Bool' (even if the language
212 /// doesn't actually have 'bool', because, e.g., it is defined as a macro).
213 LLVM_PREFERRED_TYPE(bool)
214 unsigned Bool : 1;
215
216 /// Whether we should use 'nullptr' rather than '0' as a null pointer
217 /// constant.
218 LLVM_PREFERRED_TYPE(bool)
219 unsigned Nullptr : 1;
220
221 /// Whether 'nullptr_t' is in namespace 'std' or not.
222 LLVM_PREFERRED_TYPE(bool)
223 unsigned NullptrTypeInNamespace : 1;
224
225 /// Whether we can use 'restrict' rather than '__restrict'.
226 LLVM_PREFERRED_TYPE(bool)
227 unsigned Restrict : 1;
228
229 /// Whether we can use 'alignof' rather than '__alignof'.
230 LLVM_PREFERRED_TYPE(bool)
231 unsigned Alignof : 1;
232
233 /// Whether we can use '_Alignof' rather than '__alignof'.
234 LLVM_PREFERRED_TYPE(bool)
235 unsigned UnderscoreAlignof : 1;
236
237 /// Whether we should use '(void)' rather than '()' for a function prototype
238 /// with zero parameters.
239 LLVM_PREFERRED_TYPE(bool)
240 unsigned UseVoidForZeroParams : 1;
241
242 /// Whether nested templates must be closed like 'a\<b\<c\> \>' rather than
243 /// 'a\<b\<c\>\>'.
244 LLVM_PREFERRED_TYPE(bool)
245 unsigned SplitTemplateClosers : 1;
246
247 /// Provide a 'terse' output.
248 ///
249 /// For example, in this mode we don't print function bodies, class members,
250 /// declarations inside namespaces etc. Effectively, this should print
251 /// only the requested declaration.
252 LLVM_PREFERRED_TYPE(bool)
253 unsigned TerseOutput : 1;
254
255 /// When true, do certain refinement needed for producing proper declaration
256 /// tag; such as, do not print attributes attached to the declaration.
257 ///
258 LLVM_PREFERRED_TYPE(bool)
259 unsigned PolishForDeclaration : 1;
260
261 /// When true, print the half-precision floating-point type as 'half'
262 /// instead of '__fp16'
263 LLVM_PREFERRED_TYPE(bool)
264 unsigned Half : 1;
265
266 /// When true, print the built-in wchar_t type as __wchar_t. For use in
267 /// Microsoft mode when wchar_t is not available.
268 LLVM_PREFERRED_TYPE(bool)
269 unsigned MSWChar : 1;
270
271 /// When true, include newlines after statements like "break", etc.
272 LLVM_PREFERRED_TYPE(bool)
273 unsigned IncludeNewlines : 1;
274
275 /// Use whitespace and punctuation like MSVC does. In particular, this prints
276 /// anonymous namespaces as `anonymous namespace' and does not insert spaces
277 /// after template arguments.
278 LLVM_PREFERRED_TYPE(bool)
279 unsigned MSVCFormatting : 1;
280
281 /// Whether we should print the constant expressions as written in the
282 /// sources.
283 ///
284 /// This flag determines whether constants expressions like
285 ///
286 /// \code
287 /// 0x10
288 /// 2.5e3
289 /// \endcode
290 ///
291 /// will be printed as written or as follows:
292 ///
293 /// \code
294 /// 0x10
295 /// 2.5e3
296 /// \endcode
297 LLVM_PREFERRED_TYPE(bool)
298 unsigned ConstantsAsWritten : 1;
299
300 /// When true, don't print the implicit 'self' or 'this' expressions.
301 LLVM_PREFERRED_TYPE(bool)
302 unsigned SuppressImplicitBase : 1;
303
304 /// When true, print the fully qualified name of function declarations.
305 /// This is the opposite of SuppressScope and thus overrules it.
306 LLVM_PREFERRED_TYPE(bool)
307 unsigned FullyQualifiedName : 1;
308
309 /// Whether to print types as written or canonically.
310 LLVM_PREFERRED_TYPE(bool)
311 unsigned PrintCanonicalTypes : 1;
312
313 /// Whether to print an InjectedClassNameType with template arguments or as
314 /// written. When a template argument is unnamed, printing it results in
315 /// invalid C++ code.
316 LLVM_PREFERRED_TYPE(bool)
317 unsigned PrintInjectedClassNameWithArguments : 1;
318
319 /// Whether to use C++ template preferred_name attributes when printing
320 /// templates.
321 LLVM_PREFERRED_TYPE(bool)
322 unsigned UsePreferredNames : 1;
323
324 /// Whether to use type suffixes (eg: 1U) on integral non-type template
325 /// parameters.
326 LLVM_PREFERRED_TYPE(bool)
327 unsigned AlwaysIncludeTypeForTemplateArgument : 1;
328
329 /// Whether to strip underscores when printing reserved parameter names.
330 /// e.g. std::vector<class _Tp> becomes std::vector<class Tp>.
331 /// This only affects parameter names, and so describes a compatible API.
332 LLVM_PREFERRED_TYPE(bool)
333 unsigned CleanUglifiedParameters : 1;
334
335 /// Whether to print the entire array initializers, especially on non-type
336 /// template parameters, no matter how many elements there are.
337 LLVM_PREFERRED_TYPE(bool)
338 unsigned EntireContentsOfLargeArray : 1;
339
340 /// Whether to print enumerator non-type template parameters with a matching
341 /// enumerator name or via cast of an integer.
342 LLVM_PREFERRED_TYPE(bool)
343 unsigned UseEnumerators : 1;
344
345 /// Callbacks to use to allow the behavior of printing to be customized.
346 const PrintingCallbacks *Callbacks = nullptr;
347};
348
349} // end namespace clang
350
351#endif
352

source code of clang/include/clang/AST/PrettyPrinter.h