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 
19 namespace clang {
20 
21 class LangOptions;
22 class SourceManager;
23 class Stmt;
24 class TagDecl;
25 
26 class PrinterHelper {
27 public:
28   virtual ~PrinterHelper();
29   virtual bool handledStmt(Stmt* E, raw_ostream& OS) = 0;
30 };
31 
32 /// Callbacks to use to customize the behavior of the pretty-printer.
33 class PrintingCallbacks {
34 protected:
35   ~PrintingCallbacks() = default;
36 
37 public:
38   /// Remap a path to a form suitable for printing.
39   virtual std::string remapPath(StringRef Path) const { return Path; }
40 };
41 
42 /// Describes how types, statements, expressions, and declarations should be
43 /// printed.
44 ///
45 /// This type is intended to be small and suitable for passing by value.
46 /// It is very frequently copied.
47 struct PrintingPolicy {
48   /// Create a default printing policy for the specified language.
49   PrintingPolicy(const LangOptions &LO)
50       : Indentation(2), SuppressSpecifiers(false),
51         SuppressTagKeyword(LO.CPlusPlus), IncludeTagDefinition(false),
52         SuppressScope(false), SuppressUnwrittenScope(false),
53         SuppressInitializers(false), ConstantArraySizeAsWritten(false),
54         AnonymousTagLocations(true), SuppressStrongLifetime(false),
55         SuppressLifetimeQualifiers(false),
56         SuppressTemplateArgsInCXXConstructors(false), Bool(LO.Bool),
57         Restrict(LO.C99), Alignof(LO.CPlusPlus11), UnderscoreAlignof(LO.C11),
58         UseVoidForZeroParams(!LO.CPlusPlus), TerseOutput(false),
59         PolishForDeclaration(false), Half(LO.Half),
60         MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
61         MSVCFormatting(false), ConstantsAsWritten(false),
62         SuppressImplicitBase(false), FullyQualifiedName(false),
63         PrintCanonicalTypes(false) {}
64 
65   /// Adjust this printing policy for cases where it's known that we're
66   /// printing C++ code (for instance, if AST dumping reaches a C++-only
67   /// construct). This should not be used if a real LangOptions object is
68   /// available.
69   void adjustForCPlusPlus() {
70     SuppressTagKeyword = true;
71     Bool = true;
72     UseVoidForZeroParams = false;
73   }
74 
75   /// The number of spaces to use to indent each line.
76   unsigned Indentation : 8;
77 
78   /// Whether we should suppress printing of the actual specifiers for
79   /// the given type or declaration.
80   ///
81   /// This flag is only used when we are printing declarators beyond
82   /// the first declarator within a declaration group. For example, given:
83   ///
84   /// \code
85   /// const int *x, *y;
86   /// \endcode
87   ///
88   /// SuppressSpecifiers will be false when printing the
89   /// declaration for "x", so that we will print "int *x"; it will be
90   /// \c true when we print "y", so that we suppress printing the
91   /// "const int" type specifier and instead only print the "*y".
92   unsigned SuppressSpecifiers : 1;
93 
94   /// Whether type printing should skip printing the tag keyword.
95   ///
96   /// This is used when printing the inner type of elaborated types,
97   /// (as the tag keyword is part of the elaborated type):
98   ///
99   /// \code
100   /// struct Geometry::Point;
101   /// \endcode
102   unsigned SuppressTagKeyword : 1;
103 
104   /// When true, include the body of a tag definition.
105   ///
106   /// This is used to place the definition of a struct
107   /// in the middle of another declaration as with:
108   ///
109   /// \code
110   /// typedef struct { int x, y; } Point;
111   /// \endcode
112   unsigned IncludeTagDefinition : 1;
113 
114   /// Suppresses printing of scope specifiers.
115   unsigned SuppressScope : 1;
116 
117   /// Suppress printing parts of scope specifiers that don't need
118   /// to be written, e.g., for inline or anonymous namespaces.
119   unsigned SuppressUnwrittenScope : 1;
120 
121   /// Suppress printing of variable initializers.
122   ///
123   /// This flag is used when printing the loop variable in a for-range
124   /// statement. For example, given:
125   ///
126   /// \code
127   /// for (auto x : coll)
128   /// \endcode
129   ///
130   /// SuppressInitializers will be true when printing "auto x", so that the
131   /// internal initializer constructed for x will not be printed.
132   unsigned SuppressInitializers : 1;
133 
134   /// Whether we should print the sizes of constant array expressions as written
135   /// in the sources.
136   ///
137   /// This flag determines whether array types declared as
138   ///
139   /// \code
140   /// int a[4+10*10];
141   /// char a[] = "A string";
142   /// \endcode
143   ///
144   /// will be printed as written or as follows:
145   ///
146   /// \code
147   /// int a[104];
148   /// char a[9] = "A string";
149   /// \endcode
150   unsigned ConstantArraySizeAsWritten : 1;
151 
152   /// When printing an anonymous tag name, also print the location of that
153   /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints
154   /// "(anonymous)" for the name.
155   unsigned AnonymousTagLocations : 1;
156 
157   /// When true, suppress printing of the __strong lifetime qualifier in ARC.
158   unsigned SuppressStrongLifetime : 1;
159 
160   /// When true, suppress printing of lifetime qualifier in ARC.
161   unsigned SuppressLifetimeQualifiers : 1;
162 
163   /// When true, suppresses printing template arguments in names of C++
164   /// constructors.
165   unsigned SuppressTemplateArgsInCXXConstructors : 1;
166 
167   /// Whether we can use 'bool' rather than '_Bool' (even if the language
168   /// doesn't actually have 'bool', because, e.g., it is defined as a macro).
169   unsigned Bool : 1;
170 
171   /// Whether we can use 'restrict' rather than '__restrict'.
172   unsigned Restrict : 1;
173 
174   /// Whether we can use 'alignof' rather than '__alignof'.
175   unsigned Alignof : 1;
176 
177   /// Whether we can use '_Alignof' rather than '__alignof'.
178   unsigned UnderscoreAlignof : 1;
179 
180   /// Whether we should use '(void)' rather than '()' for a function prototype
181   /// with zero parameters.
182   unsigned UseVoidForZeroParams : 1;
183 
184   /// Provide a 'terse' output.
185   ///
186   /// For example, in this mode we don't print function bodies, class members,
187   /// declarations inside namespaces etc.  Effectively, this should print
188   /// only the requested declaration.
189   unsigned TerseOutput : 1;
190 
191   /// When true, do certain refinement needed for producing proper declaration
192   /// tag; such as, do not print attributes attached to the declaration.
193   ///
194   unsigned PolishForDeclaration : 1;
195 
196   /// When true, print the half-precision floating-point type as 'half'
197   /// instead of '__fp16'
198   unsigned Half : 1;
199 
200   /// When true, print the built-in wchar_t type as __wchar_t. For use in
201   /// Microsoft mode when wchar_t is not available.
202   unsigned MSWChar : 1;
203 
204   /// When true, include newlines after statements like "break", etc.
205   unsigned IncludeNewlines : 1;
206 
207   /// Use whitespace and punctuation like MSVC does. In particular, this prints
208   /// anonymous namespaces as `anonymous namespace' and does not insert spaces
209   /// after template arguments.
210   unsigned MSVCFormatting : 1;
211 
212   /// Whether we should print the constant expressions as written in the
213   /// sources.
214   ///
215   /// This flag determines whether constants expressions like
216   ///
217   /// \code
218   /// 0x10
219   /// 2.5e3
220   /// \endcode
221   ///
222   /// will be printed as written or as follows:
223   ///
224   /// \code
225   /// 0x10
226   /// 2.5e3
227   /// \endcode
228   unsigned ConstantsAsWritten : 1;
229 
230   /// When true, don't print the implicit 'self' or 'this' expressions.
231   unsigned SuppressImplicitBase : 1;
232 
233   /// When true, print the fully qualified name of function declarations.
234   /// This is the opposite of SuppressScope and thus overrules it.
235   unsigned FullyQualifiedName : 1;
236 
237   /// Whether to print types as written or canonically.
238   unsigned PrintCanonicalTypes : 1;
239 
240   /// Callbacks to use to allow the behavior of printing to be customized.
241   const PrintingCallbacks *Callbacks = nullptr;
242 };
243 
244 } // end namespace clang
245 
246 #endif
247