[clang] Fix the double space and double attribute printing of the final keyword. (PR #88600)

[Vassil Vassilev via cfe-commits]

https://github.com/vgvassilev updated https://github.com/llvm/llvm-project/pull/88600

>From b43c52e0ab76815e745d474c40944b4de1a929ab Mon Sep 17 00:00:00 2001
From: Vassil Vassilev <v.g.vassilev at gmail.com>
Date: Sat, 13 Apr 2024 06:39:34 +0000
Subject: [PATCH] Fix the double space and double attribute printing of the
 final keyword.

Fixes #56517.
---
 clang/lib/AST/DeclPrinter.cpp               | 30 ++++++++++++---------
 clang/test/SemaCXX/cxx11-attr-print.cpp     |  5 ++++
 clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl |  4 +--
 clang/utils/TableGen/ClangAttrEmitter.cpp   |  2 +-
 4 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
index 6afdb6cfccb142..46e5b7c47ef564 100644
--- a/clang/lib/AST/DeclPrinter.cpp
+++ b/clang/lib/AST/DeclPrinter.cpp
@@ -119,7 +119,7 @@ namespace {
     void printTemplateArguments(llvm::ArrayRef<TemplateArgumentLoc> Args,
                                 const TemplateParameterList *Params);
     enum class AttrPosAsWritten { Default = 0, Left, Right };
-    void
+    bool
     prettyPrintAttributes(const Decl *D,
                           AttrPosAsWritten Pos = AttrPosAsWritten::Default);
     void prettyPrintPragmas(Decl *D);
@@ -252,10 +252,12 @@ static DeclPrinter::AttrPosAsWritten getPosAsWritten(const Attr *A,
   return DeclPrinter::AttrPosAsWritten::Right;
 }
 
-void DeclPrinter::prettyPrintAttributes(const Decl *D,
+// returns true if an attribute was printed.
+bool DeclPrinter::prettyPrintAttributes(const Decl *D,
                                         AttrPosAsWritten Pos /*=Default*/) {
+  bool hasPrinted = false;
   if (Policy.PolishForDeclaration)
-    return;
+    return hasPrinted;
 
   if (D->hasAttrs()) {
     const AttrVec &Attrs = D->getAttrs();
@@ -275,6 +277,7 @@ void DeclPrinter::prettyPrintAttributes(const Decl *D,
           if (Pos != AttrPosAsWritten::Left)
             Out << ' ';
           A->printPretty(Out, Policy);
+          hasPrinted = true;
           if (Pos == AttrPosAsWritten::Left)
             Out << ' ';
         }
@@ -282,6 +285,7 @@ void DeclPrinter::prettyPrintAttributes(const Decl *D,
       }
     }
   }
+  return hasPrinted;
 }
 
 void DeclPrinter::prettyPrintPragmas(Decl *D) {
@@ -1060,12 +1064,14 @@ void DeclPrinter::VisitCXXRecordDecl(CXXRecordDecl *D) {
   // FIXME: add printing of pragma attributes if required.
   if (!Policy.SuppressSpecifiers && D->isModulePrivate())
     Out << "__module_private__ ";
-  Out << D->getKindName();
 
-  prettyPrintAttributes(D);
+  Out << D->getKindName() << ' ';
+
+  // FIXME: Move before printing the decl kind to match the behavior of the
+  // attribute printing for variables and function where they are printed first.
+  prettyPrintAttributes(D, AttrPosAsWritten::Left);
 
   if (D->getIdentifier()) {
-    Out << ' ';
     if (auto *NNS = D->getQualifier())
       NNS->print(Out, Policy);
     Out << *D;
@@ -1082,11 +1088,8 @@ void DeclPrinter::VisitCXXRecordDecl(CXXRecordDecl *D) {
     }
   }
 
-  if (D->hasDefinition()) {
-    if (D->hasAttr<FinalAttr>()) {
-      Out << " final";
-    }
-  }
+  if (prettyPrintAttributes(D, AttrPosAsWritten::Right))
+    Out << ' ';
 
   if (D->isCompleteDefinition()) {
     // Print the base classes
@@ -1114,10 +1117,11 @@ void DeclPrinter::VisitCXXRecordDecl(CXXRecordDecl *D) {
 
     // Print the class definition
     // FIXME: Doesn't print access specifiers, e.g., "public:"
+    Out << ' ';
     if (Policy.TerseOutput) {
-      Out << " {}";
+      Out << "{}";
     } else {
-      Out << " {\n";
+      Out << "{\n";
       VisitDeclContext(D);
       Indent() << "}";
     }
diff --git a/clang/test/SemaCXX/cxx11-attr-print.cpp b/clang/test/SemaCXX/cxx11-attr-print.cpp
index a169d1b4409b4d..2b084018bc0662 100644
--- a/clang/test/SemaCXX/cxx11-attr-print.cpp
+++ b/clang/test/SemaCXX/cxx11-attr-print.cpp
@@ -87,3 +87,8 @@ template struct S<int>;
 
 // CHECK: using Small2 {{\[}}[gnu::mode(byte)]] = int;
 using Small2 [[gnu::mode(byte)]] = int;
+
+class FinalNonTemplate final {};
+// CHECK: class FinalNonTemplate final {
+template <typename T> class FinalTemplate final {};
+// CHECK: template <typename T> class FinalTemplate final {
diff --git a/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl b/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
index 7e79ae3bf005fc..b1a15c43191829 100644
--- a/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
+++ b/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
@@ -6,11 +6,11 @@ typedef vector<float, 3> float3;
 RWBuffer<float3> Buffer;
 
 // expected-error at +2 {{class template 'RWBuffer' requires template arguments}}
-// expected-note@*:* {{template declaration from hidden source: template <class element_type> class RWBuffer final}}
+// expected-note@*:* {{template declaration from hidden source: template <class element_type> class RWBuffer}}
 RWBuffer BufferErr1;
 
 // expected-error at +2 {{too few template arguments for class template 'RWBuffer'}}
-// expected-note@*:* {{template declaration from hidden source: template <class element_type> class RWBuffer final}}
+// expected-note@*:* {{template declaration from hidden source: template <class element_type> class RWBuffer}}
 RWBuffer<> BufferErr2;
 
 [numthreads(1,1,1)]
diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index 6c56f99f503df4..765cbbf3b04bcf 100644
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -1608,7 +1608,7 @@ writePrettyPrintFunction(const Record &R,
       Prefix = "[";
       Suffix = "]";
     } else if (Variety == "Keyword") {
-      Prefix = " ";
+      Prefix = "";
       Suffix = "";
     } else if (Variety == "Pragma") {
       Prefix = "#pragma ";