clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp

   1 //===--- WalkASTTest.cpp ------------------------------------------- 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 #include "AnalysisInternal.h"
   9 #include "clang-include-cleaner/Types.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/AST/Decl.h"
  12 #include "clang/AST/DeclBase.h"
  13 #include "clang/Basic/Diagnostic.h"
  14 #include "clang/Basic/DiagnosticOptions.h"
  15 #include "clang/Basic/FileManager.h"
  16 #include "clang/Basic/SourceLocation.h"
  17 #include "clang/Frontend/TextDiagnostic.h"
  18 #include "clang/Testing/TestAST.h"
  19 #include "llvm/ADT/STLExtras.h"
  20 #include "llvm/ADT/StringRef.h"
  21 #include "llvm/Support/Error.h"
  22 #include "llvm/Support/ScopedPrinter.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include "llvm/Testing/Annotations/Annotations.h"
  25 #include "gmock/gmock.h"
  26 #include "gtest/gtest.h"
  27 #include <cstddef>
  28 #include <string>
  29 #include <unordered_map>
  30 #include <utility>
  31 #include <vector>
  32
  33 namespace clang::include_cleaner {
  34 namespace {
  35 using testing::ElementsAre;
  36
  37 // Specifies a test of which symbols are referenced by a piece of code.
  38 // Target should contain points annotated with the reference kind.
  39 // Example:
  40 //   Target:      int $explicit^foo();
  41 //   Referencing: int x = ^foo();
  42 // There must be exactly one referencing location marked.
  43 // Returns target decls.
  44 std::vector<Decl::Kind> testWalk(llvm::StringRef TargetCode,
  45                                  llvm::StringRef ReferencingCode) {
  46   llvm::Annotations Target(TargetCode);
  47   llvm::Annotations Referencing(ReferencingCode);
  48
  49   TestInputs Inputs(Referencing.code());
  50   Inputs.ExtraFiles["target.h"] = Target.code().str();
  51   Inputs.ExtraArgs.push_back("-include");
  52   Inputs.ExtraArgs.push_back("target.h");
  53   Inputs.ExtraArgs.push_back("-std=c++20");
  54   TestAST AST(Inputs);
  55   const auto &SM = AST.sourceManager();
  56
  57   // We're only going to record references from the nominated point,
  58   // to the target file.
  59   FileID ReferencingFile = SM.getMainFileID();
  60   SourceLocation ReferencingLoc =
  61       SM.getComposedLoc(ReferencingFile, Referencing.point());
  62   FileID TargetFile = SM.translateFile(
  63       llvm::cantFail(AST.fileManager().getFileRef("target.h")));
  64
  65   std::vector<Decl::Kind> TargetDecls;
  66   // Perform the walk, and capture the offsets of the referenced targets.
  67   std::unordered_map<RefType, std::vector<size_t>> ReferencedOffsets;
  68   for (Decl *D : AST.context().getTranslationUnitDecl()->decls()) {
  69     if (ReferencingFile != SM.getDecomposedExpansionLoc(D->getLocation()).first)
  70       continue;
  71     walkAST(*D, [&](SourceLocation Loc, NamedDecl &ND, RefType RT) {
  72       if (SM.getFileLoc(Loc) != ReferencingLoc)
  73         return;
  74       auto NDLoc = SM.getDecomposedLoc(SM.getFileLoc(ND.getLocation()));
  75       if (NDLoc.first != TargetFile)
  76         return;
  77       ReferencedOffsets[RT].push_back(NDLoc.second);
  78       TargetDecls.push_back(ND.getKind());
  79     });
  80   }
  81   for (auto &Entry : ReferencedOffsets)
  82     llvm::sort(Entry.second);
  83
  84   // Compare results to the expected points.
  85   // For each difference, show the target point in context, like a diagnostic.
  86   std::string DiagBuf;
  87   llvm::raw_string_ostream DiagOS(DiagBuf);
  88   auto *DiagOpts = new DiagnosticOptions();
  89   DiagOpts->ShowLevel = 0;
  90   DiagOpts->ShowNoteIncludeStack = 0;
  91   TextDiagnostic Diag(DiagOS, AST.context().getLangOpts(), DiagOpts);
  92   auto DiagnosePoint = [&](llvm::StringRef Message, unsigned Offset) {
  93     Diag.emitDiagnostic(
  94         FullSourceLoc(SM.getComposedLoc(TargetFile, Offset), SM),
  95         DiagnosticsEngine::Note, Message, {}, {});
  96   };
  97   for (auto RT : {RefType::Explicit, RefType::Implicit, RefType::Ambiguous}) {
  98     auto RTStr = llvm::to_string(RT);
  99     for (auto Expected : Target.points(RTStr))
 100       if (!llvm::is_contained(ReferencedOffsets[RT], Expected))
 101         DiagnosePoint("location not marked used with type " + RTStr, Expected);
 102     for (auto Actual : ReferencedOffsets[RT])
 103       if (!llvm::is_contained(Target.points(RTStr), Actual))
 104         DiagnosePoint("location unexpectedly used with type " + RTStr, Actual);
 105   }
 106
 107   // If there were any differences, we print the entire referencing code once.
 108   if (!DiagBuf.empty())
 109     ADD_FAILURE() << DiagBuf << "\nfrom code:\n" << ReferencingCode;
 110   return TargetDecls;
 111 }
 112
 113 TEST(WalkAST, DeclRef) {
 114   testWalk("int $explicit^x;", "int y = ^x;");
 115   testWalk("int $explicit^foo();", "int y = ^foo();");
 116   testWalk("namespace ns { int $explicit^x; }", "int y = ns::^x;");
 117   testWalk("struct S { static int x; };", "int y = S::^x;");
 118   // Canonical declaration only.
 119   testWalk("extern int $explicit^x; int x;", "int y = ^x;");
 120   // Return type of `foo` isn't used.
 121   testWalk("struct S{}; S $explicit^foo();", "auto bar() { return ^foo(); }");
 122 }
 123
 124 TEST(WalkAST, TagType) {
 125   testWalk("struct $explicit^S {};", "^S *y;");
 126   testWalk("enum $explicit^E {};", "^E *y;");
 127   testWalk("struct $explicit^S { static int x; };", "int y = ^S::x;");
 128   // One explicit call from the TypeLoc in constructor spelling, another
 129   // implicit reference through the constructor call.
 130   testWalk("struct $explicit^$implicit^S { static int x; };", "auto y = ^S();");
 131 }
 132
 133 TEST(WalkAST, ClassTemplates) {
 134   // Explicit instantiation and (partial) specialization references primary
 135   // template.
 136   EXPECT_THAT(testWalk("template<typename> struct $explicit^Foo{};",
 137                        "template struct ^Foo<int>;"),
 138               ElementsAre(Decl::CXXRecord));
 139   EXPECT_THAT(testWalk("template<typename> struct $explicit^Foo{};",
 140                        "template<> struct ^Foo<int> {};"),
 141               ElementsAre(Decl::CXXRecord));
 142   EXPECT_THAT(testWalk("template<typename> struct $explicit^Foo{};",
 143                        "template<typename T> struct ^Foo<T*> {};"),
 144               ElementsAre(Decl::CXXRecord));
 145
 146   // Implicit instantiations references most relevant template.
 147   EXPECT_THAT(
 148       testWalk("template<typename> struct $explicit^Foo;", "^Foo<int> x();"),
 149       ElementsAre(Decl::Kind::ClassTemplate));
 150   EXPECT_THAT(
 151       testWalk("template<typename> struct $explicit^Foo {};", "^Foo<int> x;"),
 152       ElementsAre(Decl::CXXRecord));
 153   EXPECT_THAT(testWalk(R"cpp(
 154     template<typename> struct Foo {};
 155     template<> struct $explicit^Foo<int> {};)cpp",
 156                        "^Foo<int> x;"),
 157               ElementsAre(Decl::ClassTemplateSpecialization));
 158   EXPECT_THAT(testWalk(R"cpp(
 159     template<typename> struct Foo {};
 160     template<typename T> struct $explicit^Foo<T*> {};)cpp",
 161                        "^Foo<int *> x;"),
 162               ElementsAre(Decl::ClassTemplatePartialSpecialization));
 163   // Incomplete instantiations don't have a specific specialization associated.
 164   EXPECT_THAT(testWalk(R"cpp(
 165     template<typename> struct $explicit^Foo;
 166     template<typename T> struct Foo<T*>;)cpp",
 167                        "^Foo<int *> x();"),
 168               ElementsAre(Decl::Kind::ClassTemplate));
 169   EXPECT_THAT(testWalk(R"cpp(
 170     template<typename> struct $explicit^Foo {};
 171     template struct Foo<int>;)cpp",
 172                        "^Foo<int> x;"),
 173               ElementsAre(Decl::CXXRecord));
 174   // FIXME: This is broken due to
 175   // https://github.com/llvm/llvm-project/issues/42259.
 176   EXPECT_THAT(testWalk(R"cpp(
 177     template<typename T> struct $explicit^Foo { Foo(T); };
 178     template<> struct Foo<int> { Foo(int); };)cpp",
 179                        "^Foo x(3);"),
 180               ElementsAre(Decl::ClassTemplate));
 181 }
 182 TEST(WalkAST, VarTemplates) {
 183   // Explicit instantiation and (partial) specialization references primary
 184   // template.
 185   // FIXME: Explicit instantiations has wrong source location, they point at the
 186   // primary template location (hence we drop the reference).
 187   EXPECT_THAT(
 188       testWalk("template<typename T> T Foo = 0;", "template int ^Foo<int>;"),
 189       ElementsAre());
 190   EXPECT_THAT(testWalk("template<typename T> T $explicit^Foo = 0;",
 191                        "template<> int ^Foo<int> = 2;"),
 192               ElementsAre(Decl::Var));
 193   EXPECT_THAT(testWalk("template<typename T> T $explicit^Foo = 0;",
 194                        "template<typename T> T* ^Foo<T*> = 1;"),
 195               ElementsAre(Decl::Var));
 196
 197   // Implicit instantiations references most relevant template.
 198   // FIXME: This points at implicit specialization, instead we should point to
 199   // pattern.
 200   EXPECT_THAT(testWalk(R"cpp(
 201     template <typename T> T $explicit^Foo = 0;)cpp",
 202                        "int z = ^Foo<int>;"),
 203               ElementsAre(Decl::VarTemplateSpecialization));
 204   EXPECT_THAT(testWalk(R"cpp(
 205     template<typename T> T Foo = 0;
 206     template<> int $explicit^Foo<int> = 1;)cpp",
 207                        "int x = ^Foo<int>;"),
 208               ElementsAre(Decl::VarTemplateSpecialization));
 209   // FIXME: This points at implicit specialization, instead we should point to
 210   // explicit partial specializaiton pattern.
 211   EXPECT_THAT(testWalk(R"cpp(
 212     template<typename T> T Foo = 0;
 213     template<typename T> T* $explicit^Foo<T*> = nullptr;)cpp",
 214                        "int *x = ^Foo<int *>;"),
 215               ElementsAre(Decl::VarTemplateSpecialization));
 216   // Implicit specializations through explicit instantiations has source
 217   // locations pointing at the primary template.
 218   EXPECT_THAT(testWalk(R"cpp(
 219     template<typename T> T $explicit^Foo = 0;
 220     template int Foo<int>;)cpp",
 221                        "int x = ^Foo<int>;"),
 222               ElementsAre(Decl::VarTemplateSpecialization));
 223 }
 224 TEST(WalkAST, FunctionTemplates) {
 225   // Explicit instantiation and (partial) specialization references primary
 226   // template.
 227   // FIXME: Explicit instantiations has wrong source location, they point at the
 228   // primary template location (hence we drop the reference).
 229   EXPECT_THAT(testWalk("template<typename T> void foo(T) {}",
 230                        "template void ^foo<int>(int);"),
 231               ElementsAre());
 232   EXPECT_THAT(testWalk("template<typename T> void $explicit^foo(T);",
 233                        "template<> void ^foo<int>(int);"),
 234               ElementsAre(Decl::FunctionTemplate));
 235
 236   // Implicit instantiations references most relevant template.
 237   EXPECT_THAT(testWalk(R"cpp(
 238     template <typename T> void $explicit^foo() {})cpp",
 239                        "auto x = []{ ^foo<int>(); };"),
 240               ElementsAre(Decl::Function));
 241   EXPECT_THAT(testWalk(R"cpp(
 242     template<typename T> void foo() {}
 243     template<> void $explicit^foo<int>(){})cpp",
 244                        "auto x = []{ ^foo<int>(); };"),
 245               ElementsAre(Decl::Function));
 246   // The decl is actually the specialization, but explicit instantations point
 247   // at the primary template.
 248   EXPECT_THAT(testWalk(R"cpp(
 249     template<typename T> void $explicit^foo() {};
 250     template void foo<int>();)cpp",
 251                        "auto x = [] { ^foo<int>(); };"),
 252               ElementsAre(Decl::Function));
 253 }
 254 TEST(WalkAST, TemplateSpecializationsFromUsingDecl) {
 255   // Class templates
 256   testWalk(R"cpp(
 257 namespace ns {
 258 template<class T> class $explicit^Z {};      // primary template
 259 template<class T> class $ambiguous^Z<T*> {};  // partial specialization
 260 template<> class $ambiguous^Z<int> {};        // full specialization
 261 }
 262   )cpp",
 263            "using ns::^Z;");
 264
 265   // Var templates
 266   testWalk(R"cpp(
 267 namespace ns {
 268 template<class T> T $explicit^foo;      // primary template
 269 template<class T> T $ambiguous^foo<T*>;  // partial specialization
 270 template<> int* $ambiguous^foo<int>;     // full specialization
 271 }
 272   )cpp",
 273            "using ns::^foo;");
 274   // Function templates, no partial template specializations.
 275   testWalk(R"cpp(
 276 namespace ns {
 277 template<class T> void $ambiguous^function(T);  // primary template
 278 template<> void $ambiguous^function(int);       // full specialization
 279 }
 280   )cpp",
 281            "using ns::^function;");
 282 }
 283
 284 TEST(WalkAST, Alias) {
 285   testWalk(R"cpp(
 286     namespace ns { int x; }
 287     using ns::$explicit^x;
 288   )cpp",
 289            "int y = ^x;");
 290   testWalk("using $explicit^foo = int;", "^foo x;");
 291   testWalk("struct S {}; using $explicit^foo = S;", "^foo x;");
 292   testWalk(R"cpp(
 293     template<typename> struct Foo {};
 294     template<> struct Foo<int> {};
 295     namespace ns { using ::$explicit^Foo; })cpp",
 296            "ns::^Foo<int> x;");
 297   testWalk(R"cpp(
 298     template<typename> struct Foo {};
 299     namespace ns { using ::Foo; }
 300     template<> struct ns::$explicit^Foo<int> {};)cpp",
 301            "^Foo<int> x;");
 302   // AST doesn't have enough information to figure out whether specialization
 303   // happened through an exported type or not. So err towards attributing use to
 304   // the using-decl, specializations on the exported type should be rare and
 305   // they're not permitted on type-aliases.
 306   testWalk(R"cpp(
 307     template<typename> struct Foo {};
 308     namespace ns { using ::$explicit^Foo; }
 309     template<> struct ns::Foo<int> {};)cpp",
 310            "ns::^Foo<int> x;");
 311   testWalk(R"cpp(
 312     namespace ns { enum class foo { bar }; }
 313     using ns::foo;)cpp",
 314            "auto x = foo::^bar;");
 315   testWalk(R"cpp(
 316     namespace ns { enum foo { bar }; }
 317     using ns::foo::$explicit^bar;)cpp",
 318            "auto x = ^bar;");
 319 }
 320
 321 TEST(WalkAST, Using) {
 322   // We should report unused overloads as ambiguous.
 323   testWalk(R"cpp(
 324     namespace ns {
 325       void $explicit^x(); void $ambiguous^x(int); void $ambiguous^x(char);
 326     })cpp",
 327            "using ns::^x; void foo() { x(); }");
 328   testWalk(R"cpp(
 329     namespace ns {
 330       void $ambiguous^x(); void $ambiguous^x(int); void $ambiguous^x(char);
 331     })cpp",
 332            "using ns::^x;");
 333   testWalk("namespace ns { struct S; } using ns::$explicit^S;", "^S *s;");
 334
 335   testWalk(R"cpp(
 336     namespace ns {
 337       template<class T>
 338       class $explicit^Y {};
 339     })cpp",
 340            "using ns::^Y;");
 341   testWalk(R"cpp(
 342     namespace ns {
 343       class $explicit^Y {};
 344     })cpp",
 345            "using ns::^Y;");
 346   testWalk(R"cpp(
 347     namespace ns {
 348       template<class T>
 349       class Y {};
 350     }
 351     using ns::$explicit^Y;)cpp",
 352            "^Y<int> x;");
 353   testWalk("namespace ns { enum E {A}; } using enum ns::$explicit^E;",
 354            "auto x = ^A;");
 355 }
 356
 357 TEST(WalkAST, Namespaces) {
 358   testWalk("namespace ns { void x(); }", "using namespace ^ns;");
 359 }
 360
 361 TEST(WalkAST, TemplateNames) {
 362   testWalk("template<typename> struct $explicit^S {};", "^S<int> s;");
 363   // FIXME: Template decl has the wrong primary location for type-alias template
 364   // decls.
 365   testWalk(R"cpp(
 366       template <typename> struct S {};
 367       template <typename T> $explicit^using foo = S<T>;)cpp",
 368            "^foo<int> x;");
 369   testWalk(R"cpp(
 370       namespace ns {template <typename> struct S {}; }
 371       using ns::$explicit^S;)cpp",
 372            "^S<int> x;");
 373   testWalk(R"cpp(
 374       namespace ns {
 375         template <typename T> struct S { S(T);};
 376         template <typename T> S(T t) -> S<T>;
 377       }
 378       using ns::$explicit^S;)cpp",
 379            "^S x(123);");
 380   testWalk("template<typename> struct $explicit^S {};",
 381            R"cpp(
 382       template <template <typename> typename> struct X {};
 383       X<^S> x;)cpp");
 384   testWalk("template<typename T> struct $explicit^S { S(T); };", "^S s(42);");
 385 }
 386
 387 TEST(WalkAST, NestedTypes) {
 388   testWalk(R"cpp(
 389       struct Base { typedef int $implicit^a; };
 390       struct Derived : public Base {};)cpp",
 391            "void fun() { Derived::^a x; }");
 392   testWalk(R"cpp(
 393       struct Base { using $implicit^a = int; };
 394       struct Derived : public Base {};)cpp",
 395            "void fun() { Derived::^a x; }");
 396   testWalk(R"cpp(
 397       struct ns { struct a {}; };
 398       struct Base : public ns { using ns::$implicit^a; };
 399       struct Derived : public Base {};)cpp",
 400            "void fun() { Derived::^a x; }");
 401   testWalk(R"cpp(
 402       struct Base { struct $implicit^a {}; };
 403       struct Derived : public Base {};)cpp",
 404            "void fun() { Derived::^a x; }");
 405   testWalk("struct Base { struct $implicit^a {}; };",
 406            "struct Derived : public Base { ^a x; };");
 407   testWalk(R"cpp(
 408       struct Base { struct $implicit^a {}; };
 409       struct Derived : public Base {};
 410       struct SoDerived : public Derived {};
 411       )cpp",
 412            "void fun() { SoDerived::Derived::^a x; }");
 413 }
 414
 415 TEST(WalkAST, MemberExprs) {
 416   testWalk("struct S { static int f; };", "void foo() { S::^f; }");
 417   testWalk("struct B { static int f; }; struct S : B {};",
 418            "void foo() { S::^f; }");
 419   testWalk("struct B { static void f(); }; struct S : B {};",
 420            "void foo() { S::^f; }");
 421   testWalk("struct B { static void f(); }; ",
 422            "struct S : B { void foo() { ^f(); } };");
 423   testWalk("struct $implicit^S { void foo(); };", "void foo() { S{}.^foo(); }");
 424   testWalk(
 425       "struct S { void foo(); }; struct $implicit^X : S { using S::foo; };",
 426       "void foo() { X{}.^foo(); }");
 427   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 428            "void fun(Derived d) { d.^a; }");
 429   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 430            "void fun(Derived* d) { d->^a; }");
 431   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 432            "void fun(Derived& d) { d.^a; }");
 433   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 434            "void fun() { Derived().^a; }");
 435   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 436            "Derived foo(); void fun() { foo().^a; }");
 437   testWalk("struct Base { int a; }; struct $implicit^Derived : public Base {};",
 438            "Derived& foo(); void fun() { foo().^a; }");
 439   testWalk(R"cpp(
 440       template <typename T>
 441       struct unique_ptr {
 442         T *operator->();
 443       };
 444       struct $implicit^Foo { int a; };)cpp",
 445            "void test(unique_ptr<Foo> &V) { V->^a; }");
 446   testWalk(R"cpp(
 447       template <typename T>
 448       struct $implicit^unique_ptr {
 449         void release();
 450       };
 451       struct Foo {};)cpp",
 452            "void test(unique_ptr<Foo> &V) { V.^release(); }");
 453   // Respect the sugar type (typedef, using-type).
 454   testWalk(R"cpp(
 455       namespace ns { struct Foo { int a; }; }
 456       using $implicit^Bar = ns::Foo;)cpp",
 457            "void test(Bar b) { b.^a; }");
 458   testWalk(R"cpp(
 459       namespace ns { struct Foo { int a; }; }
 460       using ns::$implicit^Foo;)cpp",
 461            "void test(Foo b) { b.^a; }");
 462   testWalk(R"cpp(
 463       namespace ns { struct Foo { int a; }; }
 464       namespace ns2 { using Bar = ns::Foo; }
 465       using ns2::$implicit^Bar;
 466       )cpp",
 467            "void test(Bar b) { b.^a; }");
 468   testWalk(R"cpp(
 469       namespace ns { template<typename> struct Foo { int a; }; }
 470       using ns::$implicit^Foo;)cpp",
 471            "void k(Foo<int> b) { b.^a; }");
 472   // Test the dependent-type case (CXXDependentScopeMemberExpr)
 473   testWalk("template<typename T> struct $implicit^Base { void method(); };",
 474            "template<typename T> void k(Base<T> t) { t.^method(); }");
 475   testWalk("template<typename T> struct $implicit^Base { void method(); };",
 476            "template<typename T> void k(Base<T>& t) { t.^method(); }");
 477   testWalk("template<typename T> struct $implicit^Base { void method(); };",
 478            "template<typename T> void k(Base<T>* t) { t->^method(); }");
 479 }
 480
 481 TEST(WalkAST, ConstructExprs) {
 482   testWalk("struct $implicit^S {};", "S ^t;");
 483   testWalk("struct $implicit^S { S(); };", "S ^t;");
 484   testWalk("struct $implicit^S { S(int); };", "S ^t(42);");
 485   testWalk("struct $implicit^S { S(int); };", "S t = ^42;");
 486   testWalk("namespace ns { struct S{}; } using ns::$implicit^S;", "S ^t;");
 487 }
 488
 489 TEST(WalkAST, Operator) {
 490   // Operator calls are marked as implicit references as they're ADL-used and
 491   // type should be providing them.
 492   testWalk(
 493       "struct string { friend int $implicit^operator+(string, string); }; ",
 494       "int k = string() ^+ string();");
 495   // Treat member operators as regular member expr calls.
 496   testWalk("struct $implicit^string {int operator+(string); }; ",
 497            "int k = string() ^+ string();");
 498   // Make sure usage is attributed to the alias.
 499   testWalk(
 500       "struct string {int operator+(string); }; using $implicit^foo = string;",
 501       "int k = foo() ^+ string();");
 502 }
 503
 504 TEST(WalkAST, VarDecls) {
 505   // Definition uses declaration, not the other way around.
 506   testWalk("extern int $explicit^x;", "int ^x = 1;");
 507   testWalk("int x = 1;", "extern int ^x;");
 508 }
 509
 510 TEST(WalkAST, Functions) {
 511   // Definition uses declaration, not the other way around.
 512   testWalk("void $explicit^foo();", "void ^foo() {}");
 513   testWalk("void foo() {}", "void ^foo();");
 514   testWalk("template <typename> void $explicit^foo();",
 515            "template <typename> void ^foo() {}");
 516
 517   // Unresolved calls marks all the overloads.
 518   testWalk("void $ambiguous^foo(int); void $ambiguous^foo(char);",
 519            "template <typename T> void bar() { ^foo(T{}); }");
 520 }
 521
 522 TEST(WalkAST, Enums) {
 523   testWalk("enum E { $explicit^A = 42 };", "int e = ^A;");
 524   testWalk("enum class $explicit^E : int;", "enum class ^E : int {};");
 525   testWalk("enum class E : int {};", "enum class ^E : int ;");
 526   testWalk("namespace ns { enum E { $explicit^A = 42 }; }", "int e = ns::^A;");
 527   testWalk("namespace ns { enum E { A = 42 }; } using ns::E::$explicit^A;",
 528            "int e = ^A;");
 529   testWalk("namespace ns { enum E { A = 42 }; } using enum ns::$explicit^E;",
 530            "int e = ^A;");
 531   testWalk(R"(namespace ns { enum E { A = 42 }; }
 532               struct S { using enum ns::E; };)",
 533            "int e = S::^A;");
 534   testWalk(R"(namespace ns { enum E { A = 42 }; }
 535               struct S { using ns::E::A; };)",
 536            "int e = S::^A;");
 537   testWalk(R"(namespace ns { enum E { $explicit^A = 42 }; })",
 538            "namespace z = ns; int e = z::^A;");
 539   testWalk(R"(enum E { $explicit^A = 42 };)", "int e = ::^A;");
 540 }
 541
 542 TEST(WalkAST, InitializerList) {
 543   testWalk(R"cpp(
 544        namespace std {
 545         template <typename T> struct $implicit^initializer_list { const T *a, *b; };
 546        })cpp",
 547            R"cpp(
 548        const char* s = "";
 549        auto sx = ^{s};)cpp");
 550 }
 551
 552 TEST(WalkAST, Concepts) {
 553   std::string Concept = "template<typename T> concept $explicit^Foo = true;";
 554   testWalk(Concept, "template<typename T>concept Bar = ^Foo<T> && true;");
 555   testWalk(Concept, "template<^Foo T>void func() {}");
 556   testWalk(Concept, "template<typename T> requires ^Foo<T> void func() {}");
 557   testWalk(Concept, "template<typename T> void func() requires ^Foo<T> {}");
 558   testWalk(Concept, "void func(^Foo auto x) {}");
 559   testWalk(Concept, "void func() { ^Foo auto x = 1; }");
 560 }
 561
 562 TEST(WalkAST, FriendDecl) {
 563   testWalk("void $explicit^foo();", "struct Bar { friend void ^foo(); };");
 564   testWalk("struct $explicit^Foo {};", "struct Bar { friend struct ^Foo; };");
 565 }
 566
 567 TEST(WalkAST, OperatorNewDelete) {
 568   testWalk("void* $ambiguous^operator new(decltype(sizeof(int)), void*);",
 569            "struct Bar { void foo() { Bar b; ^new (&b) Bar; } };");
 570   testWalk("struct A { static void $ambiguous^operator delete(void*); };",
 571            "void foo() { A a; ^delete &a; }");
 572 }
 573 } // namespace
 574 } // namespace clang::include_cleaner