Print the full calling convention; include the Clang type if applicable.

Author: varungandhi-apple

include/swift/AST/Attr.h

@@ -159,6 +159,11 @@ class TypeAttributes {
     return ConventionArguments.getValue().Name;
   }
 
+  /// Show the string enclosed between @convention(..)'s parentheses.
+  ///
+  /// For example, @convention(foo, bar) will give the string "foo, bar".
+  void getConventionArguments(SmallVectorImpl<char> &buffer) const;
+
   bool hasOwnership() const {
     return getOwnership() != ReferenceOwnership::Strong;
   }

lib/AST/Attr.cpp

@@ -26,6 +26,7 @@
 #include "swift/AST/Types.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/Basic/Defer.h"
+#include "swift/Basic/QuotedString.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -83,6 +84,18 @@ StringRef swift::getAccessLevelSpelling(AccessLevel value) {
   llvm_unreachable("Unhandled AccessLevel in switch.");
 }
 
+void TypeAttributes::getConventionArguments(SmallVectorImpl<char> &buf) const {
+  llvm::raw_svector_ostream stream(buf);
+  auto &convention = ConventionArguments.getValue();
+  stream << convention.Name;
+  if (!convention.WitnessMethodProtocol.empty()) {
+    stream << ": " << convention.WitnessMethodProtocol;
+    return;
+  }
+  if (!convention.ClangType.empty())
+    stream << ", cType: " << QuotedString(convention.ClangType);
+}
+
 /// Given a name like "autoclosure", return the type attribute ID that
 /// corresponds to it.  This returns TAK_Count on failure.
 ///

lib/AST/TypeRepr.cpp

@@ -313,10 +313,11 @@ void AttributedTypeRepr::printAttrs(ASTPrinter &Printer,
     Printer.printSimpleAttr("@thick") << " ";
 
   if (hasAttr(TAK_convention) && Attrs.hasConvention()) {
-    // TODO: (Varun) Print clang type here!
     Printer.callPrintStructurePre(PrintStructureKind::BuiltinAttribute);
     Printer.printAttrName("@convention");
-    Printer << "(" << Attrs.getConvention() << ")";
+    SmallString<32> convention;
+    Attrs.getConventionArguments(convention);
+    Printer << "(" << convention << ")";
     Printer.printStructurePost(PrintStructureKind::BuiltinAttribute);
     Printer << " ";
   }

test/SourceKit/CursorInfo/cursor_info.swift

@@ -719,7 +719,7 @@ enum E7: String {
 // RUN: %sourcekitd-test -req=cursor -pos=206:6 %s -- -F %S/../Inputs/libIDE-mock-sdk -I %t.tmp %mcp_opt %s | %FileCheck -check-prefix=CHECK86 %s
 // RUN: %sourcekitd-test -req=cursor -pos=207:6 %s -- -F %S/../Inputs/libIDE-mock-sdk -I %t.tmp %mcp_opt %s | %FileCheck -check-prefix=CHECK86 %s
 // RUN: %sourcekitd-test -req=cursor -pos=208:6 %s -- -F %S/../Inputs/libIDE-mock-sdk -I %t.tmp %mcp_opt %s | %FileCheck -check-prefix=CHECK86 %s
-// CHECK86: <syntaxtype.attribute.builtin><syntaxtype.attribute.name>@convention</syntaxtype.attribute.name>({{[a-z_]*}})</syntaxtype.attribute.builtin>
+// CHECK86: <syntaxtype.attribute.builtin><syntaxtype.attribute.name>@convention</syntaxtype.attribute.name>({{[a-z_]*((, [a-zA-Z_]*: &quot;[^&]*&quot;)|(: [a-zA-Z0-9_]*))?}})</syntaxtype.attribute.builtin>
 
 // RUN: %sourcekitd-test -req=cursor -pos=213:8 %s -- -F %S/../Inputs/libIDE-mock-sdk -I %t.tmp %mcp_opt %s | %FileCheck -check-prefix=CHECK87 %s
 // CHECK87:      source.lang.swift.decl.struct (213:8-213:26)