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), SuppressElaboration(false), 64 SuppressInitializers(false), ConstantArraySizeAsWritten(false), 65 AnonymousTagLocations(true), SuppressStrongLifetime(false), 66 SuppressLifetimeQualifiers(false), 67 SuppressTemplateArgsInCXXConstructors(false), 68 SuppressDefaultTemplateArgs(true), Bool(LO.Bool), 69 Nullptr(LO.CPlusPlus11 || LO.C2x), NullptrTypeInNamespace(LO.CPlusPlus), 70 Restrict(LO.C99), Alignof(LO.CPlusPlus11), UnderscoreAlignof(LO.C11), 71 UseVoidForZeroParams(!LO.CPlusPlus), 72 SplitTemplateClosers(!LO.CPlusPlus11), TerseOutput(false), 73 PolishForDeclaration(false), Half(LO.Half), 74 MSWChar(LO.MicrosoftExt && !LO.WChar), IncludeNewlines(true), 75 MSVCFormatting(false), ConstantsAsWritten(false), 76 SuppressImplicitBase(false), FullyQualifiedName(false), 77 PrintCanonicalTypes(false), PrintInjectedClassNameWithArguments(true), 78 UsePreferredNames(true), AlwaysIncludeTypeForTemplateArgument(false), 79 CleanUglifiedParameters(false), EntireContentsOfLargeArray(true), 80 UseEnumerators(true) {} 81 82 /// Adjust this printing policy for cases where it's known that we're 83 /// printing C++ code (for instance, if AST dumping reaches a C++-only 84 /// construct). This should not be used if a real LangOptions object is 85 /// available. 86 void adjustForCPlusPlus() { 87 SuppressTagKeyword = true; 88 Bool = true; 89 UseVoidForZeroParams = false; 90 } 91 92 /// The number of spaces to use to indent each line. 93 unsigned Indentation : 8; 94 95 /// Whether we should suppress printing of the actual specifiers for 96 /// the given type or declaration. 97 /// 98 /// This flag is only used when we are printing declarators beyond 99 /// the first declarator within a declaration group. For example, given: 100 /// 101 /// \code 102 /// const int *x, *y; 103 /// \endcode 104 /// 105 /// SuppressSpecifiers will be false when printing the 106 /// declaration for "x", so that we will print "int *x"; it will be 107 /// \c true when we print "y", so that we suppress printing the 108 /// "const int" type specifier and instead only print the "*y". 109 unsigned SuppressSpecifiers : 1; 110 111 /// Whether type printing should skip printing the tag keyword. 112 /// 113 /// This is used when printing the inner type of elaborated types, 114 /// (as the tag keyword is part of the elaborated type): 115 /// 116 /// \code 117 /// struct Geometry::Point; 118 /// \endcode 119 unsigned SuppressTagKeyword : 1; 120 121 /// When true, include the body of a tag definition. 122 /// 123 /// This is used to place the definition of a struct 124 /// in the middle of another declaration as with: 125 /// 126 /// \code 127 /// typedef struct { int x, y; } Point; 128 /// \endcode 129 unsigned IncludeTagDefinition : 1; 130 131 /// Suppresses printing of scope specifiers. 132 unsigned SuppressScope : 1; 133 134 /// Suppress printing parts of scope specifiers that are never 135 /// written, e.g., for anonymous namespaces. 136 unsigned SuppressUnwrittenScope : 1; 137 138 /// Suppress printing parts of scope specifiers that correspond 139 /// to inline namespaces, where the name is unambiguous with the specifier 140 /// removed. 141 unsigned SuppressInlineNamespace : 1; 142 143 /// Ignore qualifiers and tag keywords as specified by elaborated type sugar, 144 /// instead letting the underlying type print as normal. 145 unsigned SuppressElaboration : 1; 146 147 /// Suppress printing of variable initializers. 148 /// 149 /// This flag is used when printing the loop variable in a for-range 150 /// statement. For example, given: 151 /// 152 /// \code 153 /// for (auto x : coll) 154 /// \endcode 155 /// 156 /// SuppressInitializers will be true when printing "auto x", so that the 157 /// internal initializer constructed for x will not be printed. 158 unsigned SuppressInitializers : 1; 159 160 /// Whether we should print the sizes of constant array expressions as written 161 /// in the sources. 162 /// 163 /// This flag determines whether array types declared as 164 /// 165 /// \code 166 /// int a[4+10*10]; 167 /// char a[] = "A string"; 168 /// \endcode 169 /// 170 /// will be printed as written or as follows: 171 /// 172 /// \code 173 /// int a[104]; 174 /// char a[9] = "A string"; 175 /// \endcode 176 unsigned ConstantArraySizeAsWritten : 1; 177 178 /// When printing an anonymous tag name, also print the location of that 179 /// entity (e.g., "enum <anonymous at t.h:10:5>"). Otherwise, just prints 180 /// "(anonymous)" for the name. 181 unsigned AnonymousTagLocations : 1; 182 183 /// When true, suppress printing of the __strong lifetime qualifier in ARC. 184 unsigned SuppressStrongLifetime : 1; 185 186 /// When true, suppress printing of lifetime qualifier in ARC. 187 unsigned SuppressLifetimeQualifiers : 1; 188 189 /// When true, suppresses printing template arguments in names of C++ 190 /// constructors. 191 unsigned SuppressTemplateArgsInCXXConstructors : 1; 192 193 /// When true, attempt to suppress template arguments that match the default 194 /// argument for the parameter. 195 unsigned SuppressDefaultTemplateArgs : 1; 196 197 /// Whether we can use 'bool' rather than '_Bool' (even if the language 198 /// doesn't actually have 'bool', because, e.g., it is defined as a macro). 199 unsigned Bool : 1; 200 201 /// Whether we should use 'nullptr' rather than '0' as a null pointer 202 /// constant. 203 unsigned Nullptr : 1; 204 205 /// Whether 'nullptr_t' is in namespace 'std' or not. 206 unsigned NullptrTypeInNamespace : 1; 207 208 /// Whether we can use 'restrict' rather than '__restrict'. 209 unsigned Restrict : 1; 210 211 /// Whether we can use 'alignof' rather than '__alignof'. 212 unsigned Alignof : 1; 213 214 /// Whether we can use '_Alignof' rather than '__alignof'. 215 unsigned UnderscoreAlignof : 1; 216 217 /// Whether we should use '(void)' rather than '()' for a function prototype 218 /// with zero parameters. 219 unsigned UseVoidForZeroParams : 1; 220 221 /// Whether nested templates must be closed like 'a\<b\<c\> \>' rather than 222 /// 'a\<b\<c\>\>'. 223 unsigned SplitTemplateClosers : 1; 224 225 /// Provide a 'terse' output. 226 /// 227 /// For example, in this mode we don't print function bodies, class members, 228 /// declarations inside namespaces etc. Effectively, this should print 229 /// only the requested declaration. 230 unsigned TerseOutput : 1; 231 232 /// When true, do certain refinement needed for producing proper declaration 233 /// tag; such as, do not print attributes attached to the declaration. 234 /// 235 unsigned PolishForDeclaration : 1; 236 237 /// When true, print the half-precision floating-point type as 'half' 238 /// instead of '__fp16' 239 unsigned Half : 1; 240 241 /// When true, print the built-in wchar_t type as __wchar_t. For use in 242 /// Microsoft mode when wchar_t is not available. 243 unsigned MSWChar : 1; 244 245 /// When true, include newlines after statements like "break", etc. 246 unsigned IncludeNewlines : 1; 247 248 /// Use whitespace and punctuation like MSVC does. In particular, this prints 249 /// anonymous namespaces as `anonymous namespace' and does not insert spaces 250 /// after template arguments. 251 unsigned MSVCFormatting : 1; 252 253 /// Whether we should print the constant expressions as written in the 254 /// sources. 255 /// 256 /// This flag determines whether constants expressions like 257 /// 258 /// \code 259 /// 0x10 260 /// 2.5e3 261 /// \endcode 262 /// 263 /// will be printed as written or as follows: 264 /// 265 /// \code 266 /// 0x10 267 /// 2.5e3 268 /// \endcode 269 unsigned ConstantsAsWritten : 1; 270 271 /// When true, don't print the implicit 'self' or 'this' expressions. 272 unsigned SuppressImplicitBase : 1; 273 274 /// When true, print the fully qualified name of function declarations. 275 /// This is the opposite of SuppressScope and thus overrules it. 276 unsigned FullyQualifiedName : 1; 277 278 /// Whether to print types as written or canonically. 279 unsigned PrintCanonicalTypes : 1; 280 281 /// Whether to print an InjectedClassNameType with template arguments or as 282 /// written. When a template argument is unnamed, printing it results in 283 /// invalid C++ code. 284 unsigned PrintInjectedClassNameWithArguments : 1; 285 286 /// Whether to use C++ template preferred_name attributes when printing 287 /// templates. 288 unsigned UsePreferredNames : 1; 289 290 /// Whether to use type suffixes (eg: 1U) on integral non-type template 291 /// parameters. 292 unsigned AlwaysIncludeTypeForTemplateArgument : 1; 293 294 /// Whether to strip underscores when printing reserved parameter names. 295 /// e.g. std::vector<class _Tp> becomes std::vector<class Tp>. 296 /// This only affects parameter names, and so describes a compatible API. 297 unsigned CleanUglifiedParameters : 1; 298 299 /// Whether to print the entire array initializers, especially on non-type 300 /// template parameters, no matter how many elements there are. 301 unsigned EntireContentsOfLargeArray : 1; 302 303 /// Whether to print enumerator non-type template parameters with a matching 304 /// enumerator name or via cast of an integer. 305 unsigned UseEnumerators : 1; 306 307 /// Callbacks to use to allow the behavior of printing to be customized. 308 const PrintingCallbacks *Callbacks = nullptr; 309 }; 310 311 } // end namespace clang 312 313 #endif 314