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), SuppressInitializers(false),
64        ConstantArraySizeAsWritten(false), AnonymousTagLocations(true),
65        SuppressStrongLifetime(false), SuppressLifetimeQualifiers(false),
66        SuppressTemplateArgsInCXXConstructors(false),
67        SuppressDefaultTemplateArgs(true), Bool(LO.Bool),
68        Nullptr(LO.CPlusPlus11 || LO.C2x), NullptrTypeInNamespace(LO.CPlusPlus),
69        Restrict(LO.C99), Alignof(LO.CPlusPlus11),
70        UnderscoreAlignof(LO.C11), UseVoidForZeroParams(!LO.CPlusPlus),
71        SplitTemplateClosers(!LO.CPlusPlus11), TerseOutput(false),
72        PolishForDeclaration(false), Half(LO.Half),
73        MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
74        MSVCFormatting(false), ConstantsAsWritten(false),
75        SuppressImplicitBase(false), FullyQualifiedName(false),
76        PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true),
77        UsePreferredNames(true), AlwaysIncludeTypeForTemplateArgument(false),
78        CleanUglifiedParameters(false), EntireContentsOfLargeArray(true),
79        UseEnumerators(true) {}
80
81  /// Adjust this printing policy for cases where it's known that we're
82  /// printing C++ code (for instance, if AST dumping reaches a C++-only
83  /// construct). This should not be used if a real LangOptions object is
84  /// available.
85  void adjustForCPlusPlus() {
86    SuppressTagKeyword = true;
87    Bool = true;
88    UseVoidForZeroParams = false;
89  }
90
91  /// The number of spaces to use to indent each line.
92  unsigned Indentation : 8;
93
94  /// Whether we should suppress printing of the actual specifiers for
95  /// the given type or declaration.
96  ///
97  /// This flag is only used when we are printing declarators beyond
98  /// the first declarator within a declaration group. For example, given:
99  ///
100  /// \code
101  /// const int *x, *y;
102  /// \endcode
103  ///
104  /// SuppressSpecifiers will be false when printing the
105  /// declaration for "x", so that we will print "int *x"; it will be
106  /// \c true when we print "y", so that we suppress printing the
107  /// "const int" type specifier and instead only print the "*y".
108  unsigned SuppressSpecifiers : 1;
109
110  /// Whether type printing should skip printing the tag keyword.
111  ///
112  /// This is used when printing the inner type of elaborated types,
113  /// (as the tag keyword is part of the elaborated type):
114  ///
115  /// \code
116  /// struct Geometry::Point;
117  /// \endcode
118  unsigned SuppressTagKeyword : 1;
119
120  /// When true, include the body of a tag definition.
121  ///
122  /// This is used to place the definition of a struct
123  /// in the middle of another declaration as with:
124  ///
125  /// \code
126  /// typedef struct { int x, y; } Point;
127  /// \endcode
128  unsigned IncludeTagDefinition : 1;
129
130  /// Suppresses printing of scope specifiers.
131  unsigned SuppressScope : 1;
132
133  /// Suppress printing parts of scope specifiers that are never
134  /// written, e.g., for anonymous namespaces.
135  unsigned SuppressUnwrittenScope : 1;
136
137  /// Suppress printing parts of scope specifiers that correspond
138  /// to inline namespaces, where the name is unambiguous with the specifier
139  /// removed.
140  unsigned SuppressInlineNamespace : 1;
141
142  /// Suppress printing of variable initializers.
143  ///
144  /// This flag is used when printing the loop variable in a for-range
145  /// statement. For example, given:
146  ///
147  /// \code
148  /// for (auto x : coll)
149  /// \endcode
150  ///
151  /// SuppressInitializers will be true when printing "auto x", so that the
152  /// internal initializer constructed for x will not be printed.
153  unsigned SuppressInitializers : 1;
154
155  /// Whether we should print the sizes of constant array expressions as written
156  /// in the sources.
157  ///
158  /// This flag determines whether array types declared as
159  ///
160  /// \code
161  /// int a[4+10*10];
162  /// char a[] = "A string";
163  /// \endcode
164  ///
165  /// will be printed as written or as follows:
166  ///
167  /// \code
168  /// int a[104];
169  /// char a[9] = "A string";
170  /// \endcode
171  unsigned ConstantArraySizeAsWritten : 1;
172
173  /// When printing an anonymous tag name, also print the location of that
174  /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints
175  /// "(anonymous)" for the name.
176  unsigned AnonymousTagLocations : 1;
177
178  /// When true, suppress printing of the __strong lifetime qualifier in ARC.
179  unsigned SuppressStrongLifetime : 1;
180
181  /// When true, suppress printing of lifetime qualifier in ARC.
182  unsigned SuppressLifetimeQualifiers : 1;
183
184  /// When true, suppresses printing template arguments in names of C++
185  /// constructors.
186  unsigned SuppressTemplateArgsInCXXConstructors : 1;
187
188  /// When true, attempt to suppress template arguments that match the default
189  /// argument for the parameter.
190  unsigned SuppressDefaultTemplateArgs : 1;
191
192  /// Whether we can use 'bool' rather than '_Bool' (even if the language
193  /// doesn't actually have 'bool', because, e.g., it is defined as a macro).
194  unsigned Bool : 1;
195
196  /// Whether we should use 'nullptr' rather than '0' as a null pointer
197  /// constant.
198  unsigned Nullptr : 1;
199
200  /// Whether 'nullptr_t' is in namespace 'std' or not.
201  unsigned NullptrTypeInNamespace : 1;
202
203  /// Whether we can use 'restrict' rather than '__restrict'.
204  unsigned Restrict : 1;
205
206  /// Whether we can use 'alignof' rather than '__alignof'.
207  unsigned Alignof : 1;
208
209  /// Whether we can use '_Alignof' rather than '__alignof'.
210  unsigned UnderscoreAlignof : 1;
211
212  /// Whether we should use '(void)' rather than '()' for a function prototype
213  /// with zero parameters.
214  unsigned UseVoidForZeroParams : 1;
215
216  /// Whether nested templates must be closed like 'a\<b\<c\> \>' rather than
217  /// 'a\<b\<c\>\>'.
218  unsigned SplitTemplateClosers : 1;
219
220  /// Provide a 'terse' output.
221  ///
222  /// For example, in this mode we don't print function bodies, class members,
223  /// declarations inside namespaces etc.  Effectively, this should print
224  /// only the requested declaration.
225  unsigned TerseOutput : 1;
226
227  /// When true, do certain refinement needed for producing proper declaration
228  /// tag; such as, do not print attributes attached to the declaration.
229  ///
230  unsigned PolishForDeclaration : 1;
231
232  /// When true, print the half-precision floating-point type as 'half'
233  /// instead of '__fp16'
234  unsigned Half : 1;
235
236  /// When true, print the built-in wchar_t type as __wchar_t. For use in
237  /// Microsoft mode when wchar_t is not available.
238  unsigned MSWChar : 1;
239
240  /// When true, include newlines after statements like "break", etc.
241  unsigned IncludeNewlines : 1;
242
243  /// Use whitespace and punctuation like MSVC does. In particular, this prints
244  /// anonymous namespaces as `anonymous namespace' and does not insert spaces
245  /// after template arguments.
246  unsigned MSVCFormatting : 1;
247
248  /// Whether we should print the constant expressions as written in the
249  /// sources.
250  ///
251  /// This flag determines whether constants expressions like
252  ///
253  /// \code
254  /// 0x10
255  /// 2.5e3
256  /// \endcode
257  ///
258  /// will be printed as written or as follows:
259  ///
260  /// \code
261  /// 0x10
262  /// 2.5e3
263  /// \endcode
264  unsigned ConstantsAsWritten : 1;
265
266  /// When true, don't print the implicit 'self' or 'this' expressions.
267  unsigned SuppressImplicitBase : 1;
268
269  /// When true, print the fully qualified name of function declarations.
270  /// This is the opposite of SuppressScope and thus overrules it.
271  unsigned FullyQualifiedName : 1;
272
273  /// Whether to print types as written or canonically.
274  unsigned PrintCanonicalTypes : 1;
275
276  /// Whether to print an InjectedClassNameType with template arguments or as
277  /// written. When a template argument is unnamed, printing it results in
278  /// invalid C++ code.
279  unsigned PrintInjectedClassNameWithArguments : 1;
280
281  /// Whether to use C++ template preferred_name attributes when printing
282  /// templates.
283  unsigned UsePreferredNames : 1;
284
285  /// Whether to use type suffixes (eg: 1U) on integral non-type template
286  /// parameters.
287  unsigned AlwaysIncludeTypeForTemplateArgument : 1;
288
289  /// Whether to strip underscores when printing reserved parameter names.
290  /// e.g. std::vector<class _Tp> becomes std::vector<class Tp>.
291  /// This only affects parameter names, and so describes a compatible API.
292  unsigned CleanUglifiedParameters : 1;
293
294  /// Whether to print the entire array initializers, especially on non-type
295  /// template parameters, no matter how many elements there are.
296  unsigned EntireContentsOfLargeArray : 1;
297
298  /// Whether to print enumerator non-type template parameters with a matching
299  /// enumerator name or via cast of an integer.
300  unsigned UseEnumerators : 1;
301
302  /// Callbacks to use to allow the behavior of printing to be customized.
303  const PrintingCallbacks *Callbacks = nullptr;
304};
305
306} // end namespace clang
307
308#endif
309