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.
remapPath(StringRef Path)39   virtual std::string remapPath(StringRef Path) const {
40     return std::string(Path);
41   }
42 };
43 
44 /// Describes how types, statements, expressions, and declarations should be
45 /// printed.
46 ///
47 /// This type is intended to be small and suitable for passing by value.
48 /// It is very frequently copied.
49 struct PrintingPolicy {
50   /// Create a default printing policy for the specified language.
PrintingPolicyPrintingPolicy51   PrintingPolicy(const LangOptions &LO)
52       : Indentation(2), SuppressSpecifiers(false),
53         SuppressTagKeyword(LO.CPlusPlus), IncludeTagDefinition(false),
54         SuppressScope(false), SuppressUnwrittenScope(false),
55         SuppressInlineNamespace(true), SuppressInitializers(false),
56         ConstantArraySizeAsWritten(false), AnonymousTagLocations(true),
57         SuppressStrongLifetime(false), SuppressLifetimeQualifiers(false),
58         SuppressTemplateArgsInCXXConstructors(false),
59         SuppressDefaultTemplateArgs(true), Bool(LO.Bool),
60         Nullptr(LO.CPlusPlus11), Restrict(LO.C99), Alignof(LO.CPlusPlus11),
61         UnderscoreAlignof(LO.C11), UseVoidForZeroParams(!LO.CPlusPlus),
62         SplitTemplateClosers(!LO.CPlusPlus11), TerseOutput(false),
63         PolishForDeclaration(false), Half(LO.Half),
64         MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true),
65         MSVCFormatting(false), ConstantsAsWritten(false),
66         SuppressImplicitBase(false), FullyQualifiedName(false),
67         PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true) {}
68 
69   /// Adjust this printing policy for cases where it's known that we're
70   /// printing C++ code (for instance, if AST dumping reaches a C++-only
71   /// construct). This should not be used if a real LangOptions object is
72   /// available.
adjustForCPlusPlusPrintingPolicy73   void adjustForCPlusPlus() {
74     SuppressTagKeyword = true;
75     Bool = true;
76     UseVoidForZeroParams = false;
77   }
78 
79   /// The number of spaces to use to indent each line.
80   unsigned Indentation : 8;
81 
82   /// Whether we should suppress printing of the actual specifiers for
83   /// the given type or declaration.
84   ///
85   /// This flag is only used when we are printing declarators beyond
86   /// the first declarator within a declaration group. For example, given:
87   ///
88   /// \code
89   /// const int *x, *y;
90   /// \endcode
91   ///
92   /// SuppressSpecifiers will be false when printing the
93   /// declaration for "x", so that we will print "int *x"; it will be
94   /// \c true when we print "y", so that we suppress printing the
95   /// "const int" type specifier and instead only print the "*y".
96   unsigned SuppressSpecifiers : 1;
97 
98   /// Whether type printing should skip printing the tag keyword.
99   ///
100   /// This is used when printing the inner type of elaborated types,
101   /// (as the tag keyword is part of the elaborated type):
102   ///
103   /// \code
104   /// struct Geometry::Point;
105   /// \endcode
106   unsigned SuppressTagKeyword : 1;
107 
108   /// When true, include the body of a tag definition.
109   ///
110   /// This is used to place the definition of a struct
111   /// in the middle of another declaration as with:
112   ///
113   /// \code
114   /// typedef struct { int x, y; } Point;
115   /// \endcode
116   unsigned IncludeTagDefinition : 1;
117 
118   /// Suppresses printing of scope specifiers.
119   unsigned SuppressScope : 1;
120 
121   /// Suppress printing parts of scope specifiers that are never
122   /// written, e.g., for anonymous namespaces.
123   unsigned SuppressUnwrittenScope : 1;
124 
125   /// Suppress printing parts of scope specifiers that correspond
126   /// to inline namespaces, where the name is unambiguous with the specifier
127   /// removed.
128   unsigned SuppressInlineNamespace : 1;
129 
130   /// Suppress printing of variable initializers.
131   ///
132   /// This flag is used when printing the loop variable in a for-range
133   /// statement. For example, given:
134   ///
135   /// \code
136   /// for (auto x : coll)
137   /// \endcode
138   ///
139   /// SuppressInitializers will be true when printing "auto x", so that the
140   /// internal initializer constructed for x will not be printed.
141   unsigned SuppressInitializers : 1;
142 
143   /// Whether we should print the sizes of constant array expressions as written
144   /// in the sources.
145   ///
146   /// This flag determines whether array types declared as
147   ///
148   /// \code
149   /// int a[4+10*10];
150   /// char a[] = "A string";
151   /// \endcode
152   ///
153   /// will be printed as written or as follows:
154   ///
155   /// \code
156   /// int a[104];
157   /// char a[9] = "A string";
158   /// \endcode
159   unsigned ConstantArraySizeAsWritten : 1;
160 
161   /// When printing an anonymous tag name, also print the location of that
162   /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints
163   /// "(anonymous)" for the name.
164   unsigned AnonymousTagLocations : 1;
165 
166   /// When true, suppress printing of the __strong lifetime qualifier in ARC.
167   unsigned SuppressStrongLifetime : 1;
168 
169   /// When true, suppress printing of lifetime qualifier in ARC.
170   unsigned SuppressLifetimeQualifiers : 1;
171 
172   /// When true, suppresses printing template arguments in names of C++
173   /// constructors.
174   unsigned SuppressTemplateArgsInCXXConstructors : 1;
175 
176   /// When true, attempt to suppress template arguments that match the default
177   /// argument for the parameter.
178   unsigned SuppressDefaultTemplateArgs : 1;
179 
180   /// Whether we can use 'bool' rather than '_Bool' (even if the language
181   /// doesn't actually have 'bool', because, e.g., it is defined as a macro).
182   unsigned Bool : 1;
183 
184   /// Whether we should use 'nullptr' rather than '0' as a null pointer
185   /// constant.
186   unsigned Nullptr : 1;
187 
188   /// Whether we can use 'restrict' rather than '__restrict'.
189   unsigned Restrict : 1;
190 
191   /// Whether we can use 'alignof' rather than '__alignof'.
192   unsigned Alignof : 1;
193 
194   /// Whether we can use '_Alignof' rather than '__alignof'.
195   unsigned UnderscoreAlignof : 1;
196 
197   /// Whether we should use '(void)' rather than '()' for a function prototype
198   /// with zero parameters.
199   unsigned UseVoidForZeroParams : 1;
200 
201   /// Whether nested templates must be closed like 'a\<b\<c\> \>' rather than
202   /// 'a\<b\<c\>\>'.
203   unsigned SplitTemplateClosers : 1;
204 
205   /// Provide a 'terse' output.
206   ///
207   /// For example, in this mode we don't print function bodies, class members,
208   /// declarations inside namespaces etc.  Effectively, this should print
209   /// only the requested declaration.
210   unsigned TerseOutput : 1;
211 
212   /// When true, do certain refinement needed for producing proper declaration
213   /// tag; such as, do not print attributes attached to the declaration.
214   ///
215   unsigned PolishForDeclaration : 1;
216 
217   /// When true, print the half-precision floating-point type as 'half'
218   /// instead of '__fp16'
219   unsigned Half : 1;
220 
221   /// When true, print the built-in wchar_t type as __wchar_t. For use in
222   /// Microsoft mode when wchar_t is not available.
223   unsigned MSWChar : 1;
224 
225   /// When true, include newlines after statements like "break", etc.
226   unsigned IncludeNewlines : 1;
227 
228   /// Use whitespace and punctuation like MSVC does. In particular, this prints
229   /// anonymous namespaces as `anonymous namespace' and does not insert spaces
230   /// after template arguments.
231   unsigned MSVCFormatting : 1;
232 
233   /// Whether we should print the constant expressions as written in the
234   /// sources.
235   ///
236   /// This flag determines whether constants expressions like
237   ///
238   /// \code
239   /// 0x10
240   /// 2.5e3
241   /// \endcode
242   ///
243   /// will be printed as written or as follows:
244   ///
245   /// \code
246   /// 0x10
247   /// 2.5e3
248   /// \endcode
249   unsigned ConstantsAsWritten : 1;
250 
251   /// When true, don't print the implicit 'self' or 'this' expressions.
252   unsigned SuppressImplicitBase : 1;
253 
254   /// When true, print the fully qualified name of function declarations.
255   /// This is the opposite of SuppressScope and thus overrules it.
256   unsigned FullyQualifiedName : 1;
257 
258   /// Whether to print types as written or canonically.
259   unsigned PrintCanonicalTypes : 1;
260 
261   /// Whether to print an InjectedClassNameType with template arguments or as
262   /// written. When a template argument is unnamed, printing it results in
263   /// invalid C++ code.
264   unsigned PrintInjectedClassNameWithArguments : 1;
265 
266   /// Callbacks to use to allow the behavior of printing to be customized.
267   const PrintingCallbacks *Callbacks = nullptr;
268 };
269 
270 } // end namespace clang
271 
272 #endif
273