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 DeclContext; 22 class LangOptions; 23 class Stmt; 24 25 class PrinterHelper { 26 public: 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. 32 class PrintingCallbacks { 33 protected: 34 ~PrintingCallbacks() = default; 35 36 public: 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. 57 struct 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), Restrict(LO.C99), Alignof(LO.CPlusPlus11), 69 UnderscoreAlignof(LO.C11), UseVoidForZeroParams(!LO.CPlusPlus), 70 SplitTemplateClosers(!LO.CPlusPlus11), TerseOutput(false), 71 PolishForDeclaration(false), Half(LO.Half), 72 MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true), 73 MSVCFormatting(false), ConstantsAsWritten(false), 74 SuppressImplicitBase(false), FullyQualifiedName(false), 75 PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true), 76 UsePreferredNames(true), AlwaysIncludeTypeForTemplateArgument(false), 77 CleanUglifiedParameters(false) {} 78 79 /// Adjust this printing policy for cases where it's known that we're 80 /// printing C++ code (for instance, if AST dumping reaches a C++-only 81 /// construct). This should not be used if a real LangOptions object is 82 /// available. 83 void adjustForCPlusPlus() { 84 SuppressTagKeyword = true; 85 Bool = true; 86 UseVoidForZeroParams = false; 87 } 88 89 /// The number of spaces to use to indent each line. 90 unsigned Indentation : 8; 91 92 /// Whether we should suppress printing of the actual specifiers for 93 /// the given type or declaration. 94 /// 95 /// This flag is only used when we are printing declarators beyond 96 /// the first declarator within a declaration group. For example, given: 97 /// 98 /// \code 99 /// const int *x, *y; 100 /// \endcode 101 /// 102 /// SuppressSpecifiers will be false when printing the 103 /// declaration for "x", so that we will print "int *x"; it will be 104 /// \c true when we print "y", so that we suppress printing the 105 /// "const int" type specifier and instead only print the "*y". 106 unsigned SuppressSpecifiers : 1; 107 108 /// Whether type printing should skip printing the tag keyword. 109 /// 110 /// This is used when printing the inner type of elaborated types, 111 /// (as the tag keyword is part of the elaborated type): 112 /// 113 /// \code 114 /// struct Geometry::Point; 115 /// \endcode 116 unsigned SuppressTagKeyword : 1; 117 118 /// When true, include the body of a tag definition. 119 /// 120 /// This is used to place the definition of a struct 121 /// in the middle of another declaration as with: 122 /// 123 /// \code 124 /// typedef struct { int x, y; } Point; 125 /// \endcode 126 unsigned IncludeTagDefinition : 1; 127 128 /// Suppresses printing of scope specifiers. 129 unsigned SuppressScope : 1; 130 131 /// Suppress printing parts of scope specifiers that are never 132 /// written, e.g., for anonymous namespaces. 133 unsigned SuppressUnwrittenScope : 1; 134 135 /// Suppress printing parts of scope specifiers that correspond 136 /// to inline namespaces, where the name is unambiguous with the specifier 137 /// removed. 138 unsigned SuppressInlineNamespace : 1; 139 140 /// Suppress printing of variable initializers. 141 /// 142 /// This flag is used when printing the loop variable in a for-range 143 /// statement. For example, given: 144 /// 145 /// \code 146 /// for (auto x : coll) 147 /// \endcode 148 /// 149 /// SuppressInitializers will be true when printing "auto x", so that the 150 /// internal initializer constructed for x will not be printed. 151 unsigned SuppressInitializers : 1; 152 153 /// Whether we should print the sizes of constant array expressions as written 154 /// in the sources. 155 /// 156 /// This flag determines whether array types declared as 157 /// 158 /// \code 159 /// int a[4+10*10]; 160 /// char a[] = "A string"; 161 /// \endcode 162 /// 163 /// will be printed as written or as follows: 164 /// 165 /// \code 166 /// int a[104]; 167 /// char a[9] = "A string"; 168 /// \endcode 169 unsigned ConstantArraySizeAsWritten : 1; 170 171 /// When printing an anonymous tag name, also print the location of that 172 /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints 173 /// "(anonymous)" for the name. 174 unsigned AnonymousTagLocations : 1; 175 176 /// When true, suppress printing of the __strong lifetime qualifier in ARC. 177 unsigned SuppressStrongLifetime : 1; 178 179 /// When true, suppress printing of lifetime qualifier in ARC. 180 unsigned SuppressLifetimeQualifiers : 1; 181 182 /// When true, suppresses printing template arguments in names of C++ 183 /// constructors. 184 unsigned SuppressTemplateArgsInCXXConstructors : 1; 185 186 /// When true, attempt to suppress template arguments that match the default 187 /// argument for the parameter. 188 unsigned SuppressDefaultTemplateArgs : 1; 189 190 /// Whether we can use 'bool' rather than '_Bool' (even if the language 191 /// doesn't actually have 'bool', because, e.g., it is defined as a macro). 192 unsigned Bool : 1; 193 194 /// Whether we should use 'nullptr' rather than '0' as a null pointer 195 /// constant. 196 unsigned Nullptr : 1; 197 198 /// Whether we can use 'restrict' rather than '__restrict'. 199 unsigned Restrict : 1; 200 201 /// Whether we can use 'alignof' rather than '__alignof'. 202 unsigned Alignof : 1; 203 204 /// Whether we can use '_Alignof' rather than '__alignof'. 205 unsigned UnderscoreAlignof : 1; 206 207 /// Whether we should use '(void)' rather than '()' for a function prototype 208 /// with zero parameters. 209 unsigned UseVoidForZeroParams : 1; 210 211 /// Whether nested templates must be closed like 'a\<b\<c\> \>' rather than 212 /// 'a\<b\<c\>\>'. 213 unsigned SplitTemplateClosers : 1; 214 215 /// Provide a 'terse' output. 216 /// 217 /// For example, in this mode we don't print function bodies, class members, 218 /// declarations inside namespaces etc. Effectively, this should print 219 /// only the requested declaration. 220 unsigned TerseOutput : 1; 221 222 /// When true, do certain refinement needed for producing proper declaration 223 /// tag; such as, do not print attributes attached to the declaration. 224 /// 225 unsigned PolishForDeclaration : 1; 226 227 /// When true, print the half-precision floating-point type as 'half' 228 /// instead of '__fp16' 229 unsigned Half : 1; 230 231 /// When true, print the built-in wchar_t type as __wchar_t. For use in 232 /// Microsoft mode when wchar_t is not available. 233 unsigned MSWChar : 1; 234 235 /// When true, include newlines after statements like "break", etc. 236 unsigned IncludeNewlines : 1; 237 238 /// Use whitespace and punctuation like MSVC does. In particular, this prints 239 /// anonymous namespaces as `anonymous namespace' and does not insert spaces 240 /// after template arguments. 241 unsigned MSVCFormatting : 1; 242 243 /// Whether we should print the constant expressions as written in the 244 /// sources. 245 /// 246 /// This flag determines whether constants expressions like 247 /// 248 /// \code 249 /// 0x10 250 /// 2.5e3 251 /// \endcode 252 /// 253 /// will be printed as written or as follows: 254 /// 255 /// \code 256 /// 0x10 257 /// 2.5e3 258 /// \endcode 259 unsigned ConstantsAsWritten : 1; 260 261 /// When true, don't print the implicit 'self' or 'this' expressions. 262 unsigned SuppressImplicitBase : 1; 263 264 /// When true, print the fully qualified name of function declarations. 265 /// This is the opposite of SuppressScope and thus overrules it. 266 unsigned FullyQualifiedName : 1; 267 268 /// Whether to print types as written or canonically. 269 unsigned PrintCanonicalTypes : 1; 270 271 /// Whether to print an InjectedClassNameType with template arguments or as 272 /// written. When a template argument is unnamed, printing it results in 273 /// invalid C++ code. 274 unsigned PrintInjectedClassNameWithArguments : 1; 275 276 /// Whether to use C++ template preferred_name attributes when printing 277 /// templates. 278 unsigned UsePreferredNames : 1; 279 280 /// Whether to use type suffixes (eg: 1U) on integral non-type template 281 /// parameters. 282 unsigned AlwaysIncludeTypeForTemplateArgument : 1; 283 284 /// Whether to strip underscores when printing reserved parameter names. 285 /// e.g. std::vector<class _Tp> becomes std::vector<class Tp>. 286 /// This only affects parameter names, and so describes a compatible API. 287 unsigned CleanUglifiedParameters : 1; 288 289 /// Callbacks to use to allow the behavior of printing to be customized. 290 const PrintingCallbacks *Callbacks = nullptr; 291 }; 292 293 } // end namespace clang 294 295 #endif 296