Expose name mangling to libclang

[eliben]

Summary

Exposes a C API to name mangling for a given cursor.

This is loosely based on https://gist.github.com/tritao/2766291, and was previously discussed on cfe-dev: http://lists.cs.uiuc.edu/pipermail/cfe-dev/2014-June/037577.html

Adding testing capability via c-index-test.

[rengolin]

Hi Eli,

Looks ok to me, but I'm not the expert. Would be good to have some negative tests, though.

cheers,
--renato

[eliben]

Attaching new patch with requests addressed

[eliben]

In D4663#4, @rengolin wrote:

Hi Eli,

Looks ok to me, but I'm not the expert. Would be good to have some negative tests, though.

cheers,
--renato

I'm not 100% what you mean as "negative tests" in this context. I did add a check that nodes that shouldn't get mangled, aren't, in this new patch. Also addressed the other review by checking MS mangling as well.

[eliben]

Following hwennborg's and pcc's advice, stripping non-printable char inserted by the Microsoft mangler.

[hans]

This looks great as far as I can tell, but I'm not familiar enough with libclang to sign off here.

[eliben]

Following Argyrios's advice, infer the mangling context from AST context

[eliben]

Remove llvm:: prefixes from isa/case, per Argyrios's request

[rengolin]

In D4663#7, @eliben wrote:

I'm not 100% what you mean as "negative tests" in this context. I did add a check that nodes that shouldn't get mangled, aren't, in this new patch. Also addressed the other review by checking MS mangling as well.

That's what I meant. :) Looks good to me, though I'm not the expert here.

cheers,
--renato

include/clang-c/Index.h

  * @}
  */
 
+/** \defgroup CINDEX_MANGLE Name Mangling API Functions
+ *
+ * @{
+ */
+
+/**
+ * \brief Retrieve the CXString representing the mangled name of the cursor.
+ */
+CINDEX_LINKAGE CXString clang_Cursor_getMangling(CXCursor);
+
+/**
+ * @}
+ */
+
 /**
  * \defgroup CINDEX_MODULE Module introspection
  *

test/Index/print-mangled-name.cpp

+// RUN: %clang_cc1 -triple i686-pc-linux-gnu -emit-pch %s -o %t_linux.ast
+// RUN: c-index-test -test-print-mangle %t_linux.ast | FileCheck %s --check-prefix=ITANIUM
+
+// RUN: %clang_cc1 -triple i686-pc-win32 -emit-pch %s -o %t_msft.ast
+// RUN: c-index-test -test-print-mangle %t_msft.ast | FileCheck %s --check-prefix=MICROSOFT
+
+int foo(int, int);
+// ITANIUM: mangled=_Z3fooii
+// MICROSOFT: mangled=?foo@@YAHHH
+
+int foo(float, int);
+// ITANIUM: mangled=_Z3foofi
+// MICROSOFT: mangled=?foo@@YAHMH
+
+struct S {
+  int x, y;
+};
+// ITANIUM: StructDecl{{.*}}mangled=]
+// MICROSOFT: StructDecl{{.*}}mangled=]
+
+int foo(S, S&);
+// ITANIUM: mangled=_Z3foo1SRS
+// MICROSOFT: mangled=?foo@@YAHUS

tools/c-index-test/c-index-test.c

 }
 
 /******************************************************************************/
+/* Mangling testing.                                                          */
+/******************************************************************************/
+
+static enum CXChildVisitResult PrintMangledName(CXCursor cursor, CXCursor p,
+                                                CXClientData d) {
+  CXString MangledName;
+  PrintCursor(cursor, NULL);
+  MangledName = clang_Cursor_getMangling(cursor);
+  printf(" [mangled=%s]\n", clang_getCString(MangledName));
+  return CXChildVisit_Continue;
+}
+
+/******************************************************************************/
 /* Bitwidth testing.                                                          */
 /******************************************************************************/
 

   else if (argc > 2 && strcmp(argv[1], "-test-print-bitwidth") == 0)
     return perform_test_load_source(argc - 2, argv + 2, "all",
                                     PrintBitWidth, 0);
+  else if (argc > 2 && strcmp(argv[1], "-test-print-mangle") == 0)
+    return perform_test_load_tu(argv[2], "all", NULL, PrintMangledName, NULL);
   else if (argc > 1 && strcmp(argv[1], "-print-usr") == 0) {
     if (argc > 2)
       return print_usrs(argv + 2, argv + argc);

tools/libclang/CIndex.cpp

 #include "CXType.h"
 #include "CursorVisitor.h"
 #include "clang/AST/Attr.h"
+#include "clang/AST/Mangle.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticCategories.h"

   return cxloc::translateSourceRange(Ctx, Loc);
 }
 
+CXString clang_Cursor_getMangling(CXCursor C) {
+  if (clang_isInvalid(C.kind) || !clang_isDeclaration(C.kind))
+    return cxstring::createEmpty();
+
+  const Decl *D = getCursorDecl(C);
+  // Mangling only works for functions and variables.
+  if (!D || !(isa<FunctionDecl>(D) || isa<VarDecl>(D)))
+    return cxstring::createEmpty();
+
+  const NamedDecl *ND = cast<NamedDecl>(D);
+  std::unique_ptr<MangleContext> MC(ND->getASTContext().createMangleContext());
+
+  std::string Buf;
+  llvm::raw_string_ostream OS(Buf);
+  MC->mangleName(ND, OS);
+  OS.flush();
+
+  // The Microsoft mangler may insert a special character in the beginning to
+  // prevent further mangling. We can strip that for display purposes.
+  if (Buf[0] == '\x01') {
+    Buf.erase(0, 1);
+  }
+  return cxstring::createDup(Buf);
+}
+
 CXString clang_getCursorDisplayName(CXCursor C) {
   if (!clang_isDeclaration(C.kind))
     return clang_getCursorSpelling(C);

tools/libclang/libclang.exports

 clang_Cursor_getArgument
 clang_Cursor_getBriefCommentText
 clang_Cursor_getCommentRange
+clang_Cursor_getMangling
 clang_Cursor_getParsedComment
 clang_Cursor_getRawCommentText
 clang_Cursor_getNumArguments