[clang-tools-extra] [clang-doc] Update serializer for improved template handling (PR #138065)

[Petr Hosek via cfe-commits]

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@@ -35,6 +35,169 @@ static void populateMemberTypeInfo(RecordInfo &I, AccessSpecifier &Access,
                                    const DeclaratorDecl *D,
                                    bool IsStatic = false);
 
+static void getTemplateParameters(const TemplateParameterList *TemplateParams,
+                                  llvm::raw_ostream &Stream) {
+  Stream << "template <";
+
+  for (unsigned i = 0; i < TemplateParams->size(); ++i) {
+    if (i > 0)
+      Stream << ", ";
+
+    const NamedDecl *Param = TemplateParams->getParam(i);
+    if (const auto *TTP = llvm::dyn_cast<TemplateTypeParmDecl>(Param)) {
+      if (TTP->wasDeclaredWithTypename())
+        Stream << "typename";
+      else
+        Stream << "class";
+      if (TTP->isParameterPack())
+        Stream << "...";
+      Stream << " " << TTP->getNameAsString();
+    } else if (const auto *NTTP =
+                   llvm::dyn_cast<NonTypeTemplateParmDecl>(Param)) {
+      NTTP->getType().print(Stream, NTTP->getASTContext().getPrintingPolicy());
+      if (NTTP->isParameterPack())
+        Stream << "...";
+      Stream << " " << NTTP->getNameAsString();
+    } else if (const auto *TTPD =
+                   llvm::dyn_cast<TemplateTemplateParmDecl>(Param)) {
+      Stream << "template <";
+      getTemplateParameters(TTPD->getTemplateParameters(), Stream);
+      Stream << "> class " << TTPD->getNameAsString();
+    }
+  }
+
+  Stream << "> ";
+}
+
+// Extract the full function prototype from a FunctionDecl including
+// Full Decl
+static llvm::SmallString<256>
+getFunctionPrototype(const FunctionDecl *FuncDecl) {
+  llvm::SmallString<256> Result;
+  llvm::raw_svector_ostream Stream(Result);
+  const ASTContext &Ctx = FuncDecl->getASTContext();
+  const auto *Method = llvm::dyn_cast<CXXMethodDecl>(FuncDecl);
+  // If it's a templated function, handle the template parameters
+  if (const auto *TmplDecl = FuncDecl->getDescribedTemplate())
+    getTemplateParameters(TmplDecl->getTemplateParameters(), Stream);
+
+  // If it's a virtual method
+  if (Method && Method->isVirtual())
+    Stream << "virtual ";
+
+  // Print return type
+  FuncDecl->getReturnType().print(Stream, Ctx.getPrintingPolicy());
+
+  // Print function name
+  Stream << " " << FuncDecl->getNameAsString() << "(";
+
+  // Print parameter list with types, names, and default values
+  for (unsigned I = 0; I < FuncDecl->getNumParams(); ++I) {
+    if (I > 0)
+      Stream << ", ";
+    const ParmVarDecl *ParamDecl = FuncDecl->getParamDecl(I);
+    QualType ParamType = ParamDecl->getType();
+    ParamType.print(Stream, Ctx.getPrintingPolicy());
+
+    // Print parameter name if it has one
+    if (!ParamDecl->getName().empty())
+      Stream << " " << ParamDecl->getNameAsString();
+
+    // Print default argument if it exists
+    if (ParamDecl->hasDefaultArg()) {
+      const Expr *DefaultArg = ParamDecl->getDefaultArg();
+      if (DefaultArg) {
+        Stream << " = ";
+        DefaultArg->printPretty(Stream, nullptr, Ctx.getPrintingPolicy());
+      }
+    }
+  }
+
+  // If it is a variadic function, add '...'
+  if (FuncDecl->isVariadic()) {
+    if (FuncDecl->getNumParams() > 0)
+      Stream << ", ";
+    Stream << "...";
+  }
+
+  Stream << ")";
+
+  // If it's a const method, add 'const' qualifier
+  if (Method) {
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petrhosek wrote:

This also needs to handle `= delete`.

https://github.com/llvm/llvm-project/pull/138065