[clang][DeclPrinter] Implement visitors for {TemplateType,NonTypeTemplate}Parms

Reviewers: sammccall, hokein

Subscribers: kristof.beyls, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73693

Author: kadircet

clang-tools-extra/clangd/unittests/FindTargetTests.cpp

@@ -215,8 +215,7 @@ TEST_F(TargetDeclTest, NestedNameSpecifier) {
     template <typename T>
     int x = [[T::]]y;
   )cpp";
-  // FIXME: We don't do a good job printing TemplateTypeParmDecls, apparently!
-  EXPECT_DECLS("NestedNameSpecifierLoc", "");
+  EXPECT_DECLS("NestedNameSpecifierLoc", "typename T");
 
   Code = R"cpp(
     namespace a { int x; }
@@ -256,8 +255,7 @@ TEST_F(TargetDeclTest, Types) {
     template<class T>
     void foo() { [[T]] x; }
   )cpp";
-  // FIXME: We don't do a good job printing TemplateTypeParmDecls, apparently!
-  EXPECT_DECLS("TemplateTypeParmTypeLoc", "");
+  EXPECT_DECLS("TemplateTypeParmTypeLoc", "class T");
   Flags.clear();
 
   // FIXME: Auto-completion in a template requires disabling delayed template
@@ -290,8 +288,7 @@ TEST_F(TargetDeclTest, Types) {
       static const int size = sizeof...([[E]]);
     };
   )cpp";
-  // FIXME: We don't do a good job printing TemplateTypeParmDecls, apparently!
-  EXPECT_DECLS("SizeOfPackExpr", "");
+  EXPECT_DECLS("SizeOfPackExpr", "typename ...E");
 
   Code = R"cpp(
     template <typename T>

clang/lib/AST/DeclPrinter.cpp

@@ -105,6 +105,8 @@ namespace {
     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
+    void VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *TTP);
+    void VisitNonTypeTemplateParmDecl(const NonTypeTemplateParmDecl *NTTP);
 
     void printTemplateParameters(const TemplateParameterList *Params,
                                  bool OmitTemplateKW = false);
@@ -1051,37 +1053,10 @@ void DeclPrinter::printTemplateParameters(const TemplateParameterList *Params,
     else
       NeedComma = true;
 
-    if (auto TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
-
-      if (const TypeConstraint *TC = TTP->getTypeConstraint())
-        TC->print(Out, Policy);
-      else if (TTP->wasDeclaredWithTypename())
-        Out << "typename";
-      else
-        Out << "class";
-
-      if (TTP->isParameterPack())
-        Out << " ...";
-      else if (!TTP->getName().empty())
-        Out << ' ';
-
-      Out << *TTP;
-
-      if (TTP->hasDefaultArgument()) {
-        Out << " = ";
-        Out << TTP->getDefaultArgument().getAsString(Policy);
-      };
+    if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
+      VisitTemplateTypeParmDecl(TTP);
     } else if (auto NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
-      StringRef Name;
-      if (IdentifierInfo *II = NTTP->getIdentifier())
-        Name = II->getName();
-      printDeclType(NTTP->getType(), Name, NTTP->isParameterPack());
-
-      if (NTTP->hasDefaultArgument()) {
-        Out << " = ";
-        NTTP->getDefaultArgument()->printPretty(Out, nullptr, Policy,
-                                                Indentation);
-      }
+      VisitNonTypeTemplateParmDecl(NTTP);
     } else if (auto TTPD = dyn_cast<TemplateTemplateParmDecl>(Param)) {
       VisitTemplateDecl(TTPD);
       // FIXME: print the default argument, if present.
@@ -1705,3 +1680,36 @@ void DeclPrinter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
   D->getInit()->printPretty(Out, nullptr, Policy, Indentation);
 }
 
+void DeclPrinter::VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *TTP) {
+  if (const TypeConstraint *TC = TTP->getTypeConstraint())
+    TC->print(Out, Policy);
+  else if (TTP->wasDeclaredWithTypename())
+    Out << "typename";
+  else
+    Out << "class";
+
+  if (TTP->isParameterPack())
+    Out << " ...";
+  else if (!TTP->getName().empty())
+    Out << ' ';
+
+  Out << *TTP;
+
+  if (TTP->hasDefaultArgument()) {
+    Out << " = ";
+    Out << TTP->getDefaultArgument().getAsString(Policy);
+  }
+}
+
+void DeclPrinter::VisitNonTypeTemplateParmDecl(
+    const NonTypeTemplateParmDecl *NTTP) {
+  StringRef Name;
+  if (IdentifierInfo *II = NTTP->getIdentifier())
+    Name = II->getName();
+  printDeclType(NTTP->getType(), Name, NTTP->isParameterPack());
+
+  if (NTTP->hasDefaultArgument()) {
+    Out << " = ";
+    NTTP->getDefaultArgument()->printPretty(Out, nullptr, Policy, Indentation);
+  }
+}

clang/unittests/AST/DeclPrinterTest.cpp

@@ -22,6 +22,7 @@
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
 #include "gtest/gtest.h"
 
 using namespace clang;
@@ -1273,6 +1274,15 @@ TEST(DeclPrinter, TestTemplateArgumentList15) {
     // Should be: with semicolon
 }
 
+TEST(DeclPrinter, TestTemplateArgumentList16) {
+  llvm::StringLiteral Code = "template<typename T1, int NT1, typename T2 = "
+                             "bool, int NT2 = 5> struct Z {};";
+  ASSERT_TRUE(PrintedDeclCXX11Matches(Code, "T1", "typename T1"));
+  ASSERT_TRUE(PrintedDeclCXX11Matches(Code, "T2", "typename T2 = bool"));
+  ASSERT_TRUE(PrintedDeclCXX11Matches(Code, "NT1", "int NT1"));
+  ASSERT_TRUE(PrintedDeclCXX11Matches(Code, "NT2", "int NT2 = 5"));
+}
+
 TEST(DeclPrinter, TestStaticAssert1) {
   ASSERT_TRUE(PrintedDeclCXX1ZMatches(
     "static_assert(true);",