[PDB] Restore the calling convention from PDB

[aleksandr.urakov]

Summary

This patch implements restoring of the calling convention from PDB. It is necessary for expressions evaluation, if we want to call a function of the debuggee process with a calling convention other than ccall.

[clayborg]

Looks good as long as all the test suite bots are happy.

[aleksandr.urakov]

Thanks!

I just have extracted the test cases in a separate test and have specified -m32 key, so the test can run also on 64-bit machines.

include/lldb/Symbol/ClangASTContext.h

public:
   CreateFunctionDeclaration(clang::DeclContext *decl_ctx, const char *name,
                             const CompilerType &function_Type, int storage,
                             bool is_inline);
 
   static CompilerType CreateFunctionType(clang::ASTContext *ast,
                                          const CompilerType &result_type,
                                          const CompilerType *args,
                                          unsigned num_args, bool is_variadic,
-                                         unsigned type_quals);
+                                         unsigned type_quals,
+                                         clang::CallingConv cc);
+
+  static CompilerType CreateFunctionType(clang::ASTContext *ast,
+                                         const CompilerType &result_type,
+                                         const CompilerType *args,
+                                         unsigned num_args, bool is_variadic,
+                                         unsigned type_quals) {
+    return ClangASTContext::CreateFunctionType(
+        ast, result_type, args, num_args, is_variadic, type_quals, clang::CC_C);
+  }
 
   CompilerType CreateFunctionType(const CompilerType &result_type,
                                   const CompilerType *args, unsigned num_args,
                                   bool is_variadic, unsigned type_quals) {
     return ClangASTContext::CreateFunctionType(
         getASTContext(), result_type, args, num_args, is_variadic, type_quals);
   }
 
+  CompilerType CreateFunctionType(const CompilerType &result_type,
+                                  const CompilerType *args, unsigned num_args,
+                                  bool is_variadic, unsigned type_quals,
+                                  clang::CallingConv cc) {
+    return ClangASTContext::CreateFunctionType(getASTContext(), result_type,
+                                               args, num_args, is_variadic,
+                                               type_quals, cc);
+  }
+
   clang::ParmVarDecl *CreateParameterDeclaration(const char *name,
                                                  const CompilerType &param_type,
                                                  int storage);
 
   void SetFunctionParameters(clang::FunctionDecl *function_decl,
                              clang::ParmVarDecl **params, unsigned num_params);
 
   CompilerType CreateBlockPointerType(const CompilerType &function_type);

lit/SymbolFile/PDB/Inputs/CallingConventionsTest.cpp

+int FuncCCall() { return 0; }
+auto FuncCCallPtr = &FuncCCall;
+
+int __stdcall FuncStdCall() { return 0; }
+auto FuncStdCallPtr = &FuncStdCall;
+
+int __fastcall FuncFastCall() { return 0; }
+auto FuncFastCallPtr = &FuncFastCall;
+
+int __vectorcall FuncVectorCall() { return 0; }
+auto FuncVectorCallPtr = &FuncVectorCall;
+
+struct S {
+  int FuncThisCall() { return 0; }
+};
+auto FuncThisCallPtr = &S::FuncThisCall;
+
+int main() {
+  return 0;
+}

lit/SymbolFile/PDB/calling-conventions.test

+REQUIRES: windows, lld
+RUN: clang-cl -m32 /Zi /GS- /c %S/Inputs/CallingConventionsTest.cpp /o %t.obj
+RUN: lld-link /debug:full /nodefaultlib /entry:main %t.obj /out:%t.exe
+RUN: lldb-test symbols -dump-ast %t.exe | FileCheck %s
+
+CHECK: Module: {{.*}}
+CHECK-DAG: int (*FuncCCallPtr)();
+CHECK-DAG: int (*FuncStdCallPtr)() __attribute__((stdcall));
+CHECK-DAG: int (*FuncFastCallPtr)() __attribute__((fastcall));
+CHECK-DAG: int (*FuncVectorCallPtr)() __attribute__((vectorcall));
+CHECK-DAG: int (S::*FuncThisCallPtr)() __attribute__((thiscall));

lit/SymbolFile/PDB/pointers.test

 MAIN-NEXT:  Block{[[FID1]]}
 MAIN:     Variable{{.*}}, name = "array_pointer"
 MAIN-SAME:    (int (*)[2][4]), scope = local
 MAIN:     Variable{{.*}}, name = "p_int"
 MAIN-SAME:    (int *), scope = local
 MAIN:     Variable{{.*}}, name = "p_member_field"
 MAIN-SAME:    (int ST::*), scope = local
 MAIN:     Variable{{.*}}, name = "p_member_method"
-MAIN-SAME:    (int (ST::*)(int)), scope = local
+MAIN-SAME:    (int (ST::*)(int) __attribute__((thiscall))), scope = local
 
 F:   Function{[[FID2:.*]]}, demangled = {{.*}}f(int)
 F-NEXT:  Block{[[FID2]]}
 F:     Variable{{.*}}, name = "this"
 F-SAME:    (ST *), scope = parameter, location = {{.*}}, artificial
 F:     Variable{{.*}}, name = "x"
 F-SAME:    (int), scope = parameter, decl = PointerTypeTest.cpp:8

source/Plugins/SymbolFile/PDB/PDBASTParser.cpp

GetDeclFromContextByName(const clang::ASTContext &ast,
 
   return result[0];
 }
 
 static bool IsAnonymousNamespaceName(const std::string &name) {
   return name == "`anonymous namespace'" || name == "`anonymous-namespace'";
 }
 
+static clang::CallingConv TranslateCallingConvention(PDB_CallingConv pdb_cc) {
+  switch (pdb_cc) {
+  case llvm::codeview::CallingConvention::NearC:
+    return clang::CC_C;
+  case llvm::codeview::CallingConvention::NearStdCall:
+    return clang::CC_X86StdCall;
+  case llvm::codeview::CallingConvention::NearFast:
+    return clang::CC_X86FastCall;
+  case llvm::codeview::CallingConvention::ThisCall:
+    return clang::CC_X86ThisCall;
+  case llvm::codeview::CallingConvention::NearVector:
+    return clang::CC_X86VectorCall;
+  case llvm::codeview::CallingConvention::NearPascal:
+    return clang::CC_X86Pascal;
+  default:
+    assert(false && "Unknown calling convention");
+    return clang::CC_C;
+  }
+}
+
 PDBASTParser::PDBASTParser(lldb_private::ClangASTContext &ast) : m_ast(ast) {}
 
 PDBASTParser::~PDBASTParser() {}
 
 // DebugInfoASTParser interface
 
 lldb::TypeSP PDBASTParser::CreateLLDBTypeFromPDBType(const PDBSymbol &type) {
   Declaration decl;
case PDB_SymType::FunctionSig: {
     if (!return_type)
       return nullptr;
     CompilerType return_ast_type = return_type->GetFullCompilerType();
     uint32_t type_quals = 0;
     if (func_sig->isConstType())
       type_quals |= clang::Qualifiers::Const;
     if (func_sig->isVolatileType())
       type_quals |= clang::Qualifiers::Volatile;
+    auto cc = TranslateCallingConvention(func_sig->getCallingConvention());
     CompilerType func_sig_ast_type =
         m_ast.CreateFunctionType(return_ast_type, arg_list.data(),
-                                 arg_list.size(), is_variadic, type_quals);
+                                 arg_list.size(), is_variadic, type_quals, cc);
 
     GetDeclarationForSymbol(type, decl);
     return std::make_shared<lldb_private::Type>(
         type.getSymIndexId(), m_ast.GetSymbolFile(), ConstString(name), 0,
         nullptr, LLDB_INVALID_UID, lldb_private::Type::eEncodingIsUID, decl,
         func_sig_ast_type, lldb_private::Type::eResolveStateFull);
   } break;
   case PDB_SymType::ArrayType: {

source/Symbol/ClangASTContext.cpp

#ifdef LLDB_CONFIGURATION_DEBUG
   VerifyDecl(func_decl);
 #endif
 
   return func_decl;
 }
 
 CompilerType ClangASTContext::CreateFunctionType(
     ASTContext *ast, const CompilerType &result_type, const CompilerType *args,
-    unsigned num_args, bool is_variadic, unsigned type_quals) {
+    unsigned num_args, bool is_variadic, unsigned type_quals,
+    clang::CallingConv cc) {
   if (ast == nullptr)
     return CompilerType(); // invalid AST
 
   if (!result_type || !ClangUtil::IsClangType(result_type))
     return CompilerType(); // invalid return type
 
   std::vector<QualType> qual_type_args;
   if (num_args > 0 && args == nullptr)
if (args[i]) {
       else
         return CompilerType(); //  invalid argument type (must be a clang type)
     } else
       return CompilerType(); // invalid argument type (empty)
   }
 
   // TODO: Detect calling convention in DWARF?
   FunctionProtoType::ExtProtoInfo proto_info;
+  proto_info.ExtInfo = cc;
   proto_info.Variadic = is_variadic;
   proto_info.ExceptionSpec = EST_None;
   proto_info.TypeQuals = type_quals;
   proto_info.RefQualifier = RQ_None;
 
   return CompilerType(ast,
                       ast->getFunctionType(ClangUtil::GetQualType(result_type),
                                            qual_type_args, proto_info));