[ExtractAPI] Format typedef params correctly (llvm#171516)

Typically, pointer types are formatted in a way where the identifier
comes right after the type definition without a space separating them,
e.g. `int *foo`, where the type is `int *` and the identifier is `foo`.
However, if a type alias to a pointer type is used, the emitted
declaration fragments are incorrect due to the missing space between the
type and identifier, like in the below example:

```
typedef int *T;
// The declaration fragment contains `Tbar` instead of `T bar`
void foo(T bar);
```

This patch checks if pointer types are aliased, and inserts the space
correctly if so.

rdar://132022003
(cherry picked from commit 794218b)

Author: snprajwal

clang/lib/ExtractAPI/DeclarationFragments.cpp

@@ -636,7 +636,10 @@ DeclarationFragmentsBuilder::getFragmentsForParam(const ParmVarDecl *Param) {
                 DeclarationFragments::FragmentKind::InternalParam);
   } else {
     Fragments.append(std::move(TypeFragments));
-    if (!T->isAnyPointerType() && !T->isBlockPointerType())
+    // If the type is a type alias, append the space
+    // even if the underlying type is a pointer type.
+    if (T->isTypedefNameType() ||
+        (!T->isAnyPointerType() && !T->isBlockPointerType()))
       Fragments.appendSpace();
     Fragments
         .append(Param->getName(),

clang/test/ExtractAPI/typedef.c

@@ -1,5 +1,5 @@
 // RUN: rm -rf %t
-// RUN: %clang_cc1 -extract-api --pretty-sgf --emit-sgf-symbol-labels-for-testing \
+// RUN: %clang_cc1 -extract-api --pretty-sgf --emit-sgf-symbol-labels-for-testing -fblocks \
 // RUN:   -triple arm64-apple-macosx -x objective-c-header %s -o %t/output.symbols.json -verify
 
 // RUN: FileCheck %s --input-file %t/output.symbols.json --check-prefix MYINT
@@ -90,4 +90,83 @@ void foo(BarPtr value);
 void baz(BarPtr *value);
 // CHECK-NOT: struct Bar *
 
+// RUN: FileCheck %s --input-file %t/output.symbols.json --check-prefix BLOCKPTR
+typedef int (^CustomType)(const unsigned int *, unsigned long);
+void bar(CustomType block);
+
+// BLOCKPTR-LABEL: "!testLabel": "c:@F@bar",
+// BLOCKPTR:           "declarationFragments": [
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "typeIdentifier",
+// BLOCKPTR-NEXT:          "preciseIdentifier": "c:v",
+// BLOCKPTR-NEXT:          "spelling": "void"
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "text",
+// BLOCKPTR-NEXT:          "spelling": " "
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "identifier",
+// BLOCKPTR-NEXT:          "spelling": "bar"
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "text",
+// BLOCKPTR-NEXT:          "spelling": "("
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "typeIdentifier",
+// BLOCKPTR-NEXT:          "preciseIdentifier": "c:typedef.c@T@CustomType",
+// BLOCKPTR-NEXT:          "spelling": "CustomType"
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "text",
+// BLOCKPTR-NEXT:          "spelling": " "
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "internalParam",
+// BLOCKPTR-NEXT:          "spelling": "block"
+// BLOCKPTR-NEXT:        },
+// BLOCKPTR-NEXT:        {
+// BLOCKPTR-NEXT:          "kind": "text",
+// BLOCKPTR-NEXT:          "spelling": ");"
+// BLOCKPTR-NEXT:        }
+// BLOCKPTR-NEXT:      ],
+// BLOCKPTR-NEXT:      "functionSignature": {
+// BLOCKPTR-NEXT:        "parameters": [
+// BLOCKPTR-NEXT:          {
+// BLOCKPTR-NEXT:            "declarationFragments": [
+// BLOCKPTR-NEXT:              {
+// BLOCKPTR-NEXT:                "kind": "typeIdentifier",
+// BLOCKPTR-NEXT:                "preciseIdentifier": "c:typedef.c@T@CustomType",
+// BLOCKPTR-NEXT:                "spelling": "CustomType"
+// BLOCKPTR-NEXT:              },
+// BLOCKPTR-NEXT:              {
+// BLOCKPTR-NEXT:                "kind": "text",
+// BLOCKPTR-NEXT:                "spelling": " "
+// BLOCKPTR-NEXT:              },
+// BLOCKPTR-NEXT:              {
+// BLOCKPTR-NEXT:                "kind": "internalParam",
+// BLOCKPTR-NEXT:                "spelling": "block"
+// BLOCKPTR-NEXT:              }
+// BLOCKPTR-NEXT:            ],
+// BLOCKPTR-NEXT:            "name": "block"
+// BLOCKPTR-NEXT:          }
+// BLOCKPTR-NEXT:        ],
+// BLOCKPTR-NEXT:        "returns": [
+// BLOCKPTR-NEXT:          {
+// BLOCKPTR-NEXT:            "kind": "typeIdentifier",
+// BLOCKPTR-NEXT:            "preciseIdentifier": "c:v",
+// BLOCKPTR-NEXT:            "spelling": "void"
+// BLOCKPTR-NEXT:          }
+// BLOCKPTR-NEXT:        ]
+// BLOCKPTR-NEXT:      },
+// BLOCKPTR:           "identifier": {
+// BLOCKPTR-NEXT:        "interfaceLanguage": "objective-c",
+// BLOCKPTR-NEXT:        "precise": "c:@F@bar"
+// BLOCKPTR-NEXT:      },
+// BLOCKPTR:           "kind": {
+// BLOCKPTR-NEXT:        "displayName": "Function",
+// BLOCKPTR-NEXT:        "identifier": "objective-c.func"
+// BLOCKPTR-NEXT:      },
+
 // expected-no-diagnostics