https://github.com/isuckatcs created https://github.com/llvm/llvm-project/pull/69971
https://github.com/llvm/llvm-project/commit/ae7c9443559ac420a6f401b7a24eb2fcea8ba3e8 `[AST] Fix printing tag decl groups in decl contexts` introduced a change that made sure, that implicitly created `TagDecl`s are not printed by `-ast-print`. This change however also introduced a side-effect, where non-compiling code is printed or the printer crashes. An example of the non compiling code being printed: ```c++ struct A { int x; }; struct Class { struct obj *(*next)(struct A *q); }; ``` ```c++ // Result of -ast-print struct A { int x; }; struct Class { struct obj *(*next)(struct A { int x; } *); }; ``` An example of a crash: ```c++ struct Class { struct obj *(*next)(struct Class *q); }; ``` The issue is casued by how an undefined `struct obj` is modeled. ```c++ struct Class { struct foo *p1; }; ``` ``` `-CXXRecordDecl ... struct Class definition |-... |-CXXRecordDecl ... implicit struct Class |-CXXRecordDecl ... parent &TranslationUnitDecl ... struct foo `-FieldDecl ... p1 'struct foo *' ``` ``` `-RecordDecl ... struct Class definition |-RecordDecl ... parent &TranslationUnitDecl ... struct foo `-FieldDecl ... p1 'struct foo *' ``` In `C++` a new `CXXRecordDecl`, while in `C` a new `RecordDecl` node is inserted, with their parent set to the `TranslationUnitDecl`. This inserted record is not spelled in the source code and we want to avoid treating it as a part of the `DeclContext` too, unless it has a definition in which case we want to print the definition. ```c++ struct Class { struct foo { int x; } *p1; }; ``` ``` `-CXXRecordDecl ... struct Class definition |-... |-CXXRecordDecl ... struct foo definition | |-... `-FieldDecl ... p1 'struct foo *' ``` ``` `-RecordDecl ... struct Class definition |-RecordDecl ... parent &TranslationUnitDecl struct foo definition | `-... `-FieldDecl ... p1 'struct foo *' ``` Note that in `C` the parent of the definition is still set to the `TranslationUnitDecl`, while in `C++` a nested `CXXRecordDecl` is created. Fixes #69350 >From f4023d4d5d6a6f35ef2315f1b1ce7dd35f24e901 Mon Sep 17 00:00:00 2001 From: isuckatcs <65320245+isucka...@users.noreply.github.com> Date: Mon, 23 Oct 2023 22:46:47 +0200 Subject: [PATCH] fix --- clang/lib/AST/DeclPrinter.cpp | 19 ++++++++++++++++++- clang/test/Sema/ast-print.c | 20 ++++++++++++++++++++ clang/test/SemaCXX/ast-print.cpp | 25 +++++++++++++++++++++++++ 3 files changed, 63 insertions(+), 1 deletion(-) diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp index daa219b43c4e6cf..e14933374340666 100644 --- a/clang/lib/AST/DeclPrinter.cpp +++ b/clang/lib/AST/DeclPrinter.cpp @@ -519,7 +519,24 @@ void DeclPrinter::VisitDeclContext(DeclContext *DC, bool Indent) { // If the current declaration is not a free standing declaration, save it // so we can merge it with the subsequent declaration(s) using it. if (isa<TagDecl>(*D) && !cast<TagDecl>(*D)->isFreeStanding()) { - Decls.push_back(*D); + + // Here we try to filter out the implicitly inserted tag declarations. + // E.g.: + // struct Class { + // struct foo *p1; + // ; + // + // CXXRecordDecl ... Class ... + // |-CXXRecordDecl ... parent ... struct foo <-- ignore this + // `-FieldDecl ... p1 'struct foo *' + // + // If `struct foo` has a definition, it will be modeled as a nested record + // inside `Class`, so the first condition will be true, unless we are in + // C, where `struct foo` will be a child of the translation unit node. In + // both cases if there is a definition, we want to print it. + if (cast<TagDecl>(*D)->getParent() == DC || + cast<TagDecl>(*D)->getDefinition()) + Decls.push_back(*D); continue; } diff --git a/clang/test/Sema/ast-print.c b/clang/test/Sema/ast-print.c index 2ba5ca34b513474..bb0990e020d49ce 100644 --- a/clang/test/Sema/ast-print.c +++ b/clang/test/Sema/ast-print.c @@ -104,3 +104,23 @@ void EnumWithAttributes3Fn(void) { // move to this use of the variable. void *p = EnumWithAttributes3Ptr; } + +// CHECK: struct Recursive { +// CHECK-NEXT: struct obj *(*next)(struct Recursive *); +// CHECK-NEXT: }; +struct Recursive { + struct obj *(*next)(struct Recursive *q); +}; + +// CHECK: struct A { +// CHECK-NEXT: int x; +// CHECK-NEXT: }; +// CHECK-NEXT: struct Foo { +// CHECK-NEXT: struct obj *(*next)(struct A *); +// CHECK-NEXT: ; +struct A { + int x; +}; +struct Foo { + struct obj *(*next)(struct A *q); +}; diff --git a/clang/test/SemaCXX/ast-print.cpp b/clang/test/SemaCXX/ast-print.cpp index 2cb1ec440b6bb37..c71626ad96fecff 100644 --- a/clang/test/SemaCXX/ast-print.cpp +++ b/clang/test/SemaCXX/ast-print.cpp @@ -243,3 +243,28 @@ struct S { constexpr auto var = T::X; //CHECK: constexpr auto var = T::X; } + +namespace RecursiveClass { +// CHECK: struct Recursive { +// CHECK-NEXT: struct obj *(*next)(struct Recursive *); +// CHECK-NEXT: }; +struct Recursive { + struct obj *(*next)(struct Recursive *q); +}; +} + +namespace ClassParameter { +// CHECK: struct A { +// CHECK-NEXT: int x; +// CHECK-NEXT: }; +// CHECK-NEXT: struct Foo { +// CHECK-NEXT: struct obj *(*next)(struct A *); +// CHECK-NEXT: ; +struct A { + int x; +}; + +struct Foo { + struct obj *(*next)(struct A *q); +}; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
