[clang][IFS] Escape mangled name in-order to not break llvm-ifs with names mangled using MS ABI

[plotfi]

Summary

Microsoft's ABI mangles names differently than Itanium and this breaks the LLVM yaml parser unless the name is escaped in quotes.

[thakis]

On macOS symbols are prefixed with an underscore:

Command Output (stderr):
--
/Users/thakis/src/llvm-project/clang/test/InterfaceStubs/object.c:5:16: error: CHECK-TAPI: expected string not found in input
// CHECK-TAPI: "data" : { Type: Object, Size: 4 }
               ^
<stdin>:1:1: note: scanning from here
--- !experimental-ifs-v1
^
<stdin>:6:3: note: possible intended match here
 "_data" : { Type: Object, Size: 4 }
  ^

--
********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
Testing Time: 164.94s
********************
Failing Tests (1):
    Clang :: InterfaceStubs/object.c``

[plotfi]

I see what went wrong. Will post a fix shortly.

In D68915#1708297, @thakis wrote:

On macOS symbols are prefixed with an underscore:

Command Output (stderr):
--
/Users/thakis/src/llvm-project/clang/test/InterfaceStubs/object.c:5:16: error: CHECK-TAPI: expected string not found in input
// CHECK-TAPI: "data" : { Type: Object, Size: 4 }
               ^
<stdin>:1:1: note: scanning from here
--- !experimental-ifs-v1
^
<stdin>:6:3: note: possible intended match here
 "_data" : { Type: Object, Size: 4 }
  ^

--
********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. 
Testing Time: 164.94s
********************
Failing Tests (1):
    Clang :: InterfaceStubs/object.c``

lib/Frontend/InterfaceStubFunctionsConsumer.cpp

       for (const auto &E : Symbols) {
         const MangledSymbol &Symbol = E.second;
         for (auto Name : Symbol.Names) {
-          OS << "  "
+          OS << "  \""
              << (Symbol.ParentName.empty() || Instance.getLangOpts().CPlusPlus
                      ? ""
                      : (Symbol.ParentName + "."))
-             << Name << ": { Type: ";
+             << Name << "\" : { Type: ";
           switch (Symbol.Type) {
           default:
             llvm_unreachable(

test/InterfaceStubs/inline.c

 // RUN: -c -std=gnu89 -xc %s | llvm-nm - 2>&1 | \
 // RUN: FileCheck -check-prefix=CHECK-SYMBOLS %s
 
-// CHECK-TAPI-DAG: foo: { Type: Func }
-// CHECK-TAPI-DAG: foo.var: { Type: Object, Size: 4 }
+// CHECK-TAPI-DAG: "foo" : { Type: Func }
+// CHECK-TAPI-DAG: "foo.var" : { Type: Object, Size: 4 }
 // CHECK-SYMBOLS-DAG: foo
 // CHECK-SYMBOLS-DAG: foo.var
 #include "inline.h"

test/InterfaceStubs/object.c

 // RUN: %clang -fvisibility=default -c -o - -emit-interface-stubs %s | FileCheck -check-prefix=CHECK-SYMBOLS %s
 // RUN: %clang -fvisibility=default -c -o - %s | llvm-nm - 2>&1 | FileCheck -check-prefix=CHECK-SYMBOLS %s
 
-// CHECK-TAPI: data: { Type: Object, Size: 4 }
+// CHECK-TAPI: "data" : { Type: Object, Size: 4 }
 // CHECK-SYMBOLS: data
 int data = 42;

test/InterfaceStubs/windows.cpp

+// REQUIRES: x86-registered-target
+// RUN: %clang -target x86_64-windows-msvc -o - %s \
+// RUN: -emit-interface-stubs -emit-merged-ifs | FileCheck %s
+
+// CHECK: Symbols:
+// CHECK-NEXT: ?helloWindowsMsvc@@YAHXZ
+int helloWindowsMsvc();