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