/// MS-COFF anonymous object format.
///
/// Sources:
/// - Microsoft documentation
/// - https://github.com/dlang/dmd/blob/master/compiler/src/dmd/backend/mscoff.d
///
/// Authors: dd86k <dd@dax.moe>
/// Copyright: © dd86k <dd@dax.moe>
/// License: BSD-3-Clause-Clear
module adbg.object.format.mscoff;

// NOTE: PE32/PE-COFF is an extension of COFF and MZ

import adbg.object.server : AdbgObject, adbg_object_t;
import adbg.utils.uid;

//
// Non-COFF Object file headers (.obj from VS2002-VS2015, mscoff)
//

enum {
	MSCOFF_VERSION_IMPORT = 0,
	MSCOFF_VERSION_ANON   = 1,
	MSCOFF_VERSION_ANONV2 = 2,
}

enum {
	MSCOFF_OBJECT_CODE = 0,
	MSCOFF_OBJECT_DATA = 1,
	MSCOFF_OBJECT_CONST = 2,
}

enum {
	/// Import by ordinal
	MSCOFF_IMPORT_NAME_ORDINAL = 0,
	/// Import name is public symbol name.
	MSCOFF_IMPORT_NAME = 1,
	/// Import name is public symbol name skipping leading "?", "@", or optionally "_".
	MSCOFF_IMPORT_NAME_NO_PREFIX = 2,
	/// Import name is public symbol name skipping leading "?", "@", or optionally "_"
	/// and truncating at first "@".
	MSCOFF_IMPORT_NAME_UNDECORATE = 3,
	/// Import name is a name is explicitly provided after the DLL name.
	MSCOFF_IMPORT_NAME_EXPORTAS = 4,
}

struct mscoff_import_header { // IMPORT_OBJECT_HEADER
	/// Must be IMAGE_FILE_MACHINE_UNKNOWN.
	ushort Sig1;
	/// Must be 0xFFFF.
	ushort Sig2;
	/// Must be 0.
	ushort Version;
	/// PE32 machine.
	ushort Machine;
	/// Seconds since 1970.
	uint TimeStamp;
	
	uint Size;
	ushort Ordinal; // or Hint
	// Type : 2 -> IMPORT_TYPE
	// NameType : 3 -> IMPORT_NAME_TYPE
	// Reserved : 11
	ulong Flags;
}

struct mscoff_anon_header { // ANON_OBJECT_HEADER
	ushort Sig1;            // Must be IMAGE_FILE_MACHINE_UNKNOWN
	ushort Sig2;            // Must be 0xffff
	ushort Version;         // >= 1 (implies the CLSID field is present)
	ushort Machine;
	uint   TimeDateStamp;
	
	/*CLSID*/ UID   ClassID;         // Used to invoke CoCreateInstance
	uint   SizeOfData;      // Size of data that follows the header
}

struct mscoff_anon_header_v2 { // ANON_OBJECT_HEADER_V2
	ushort Sig1;            // Must be IMAGE_FILE_MACHINE_UNKNOWN
	ushort Sig2;            // Must be 0xffff
	ushort Version;         // >= 2 (implies the Flags field is present - otherwise V1)
	ushort Machine;
	uint   TimeDateStamp;
	
	/* CLSID */ UID   ClassID;         // Used to invoke CoCreateInstance
	uint   SizeOfData;      // Size of data that follows the header
	uint   Flags;           // 0x1 -> contains metadata
	uint   MetaDataSize;    // Size of CLR metadata
	uint   MetaDataOffset;  // Offset of CLR metadata
}

struct mscoff_anon_header_bigobj { // ANON_OBJECT_HEADER_BIGOBJ
	/* same as ANON_OBJECT_HEADER_V2 */
	ushort Sig1;            // Must be IMAGE_FILE_MACHINE_UNKNOWN
	ushort Sig2;            // Must be 0xffff
	ushort Version;         // >= 2 (implies the Flags field is present)
	ushort Machine;         // Actual machine - IMAGE_FILE_MACHINE_xxx
	uint   TimeDateStamp;
	
	/* CLSID */ UID   ClassID;         // {D1BAA1C7-BAEE-4ba9-AF20-FAF66AA4DCB8}
	uint   SizeOfData;      // Size of data that follows the header, could be zero
	uint   Flags;           // 0x1 -> contains metadata
	uint   MetaDataSize;    // Size of CLR metadata
	uint   MetaDataOffset;  // Offset of CLR metadata

	/* bigobj specifics */
	uint   NumberOfSections; // extended from WORD
	uint   PointerToSymbolTable;
	uint   NumberOfSymbols;
}

// Same as PE32
enum SYMNMLEN = 8;

struct mscoff_anon_symbol_table32 {
	union {
		ubyte[SYMNMLEN] Name;
		struct {
			uint Zeros;
			uint Offset;
		}
	}
	uint Value;
	int SectionNumber;
	ushort Type;
	ubyte StorageClass;
	ubyte NumberOfAuxSymbols;
}
static assert(mscoff_anon_symbol_table32.sizeof == 20);

struct mscoff_anon_symbol_table { align(1):
	ubyte[SYMNMLEN] Name;
	uint Value;
	short SectionNumber;
	ushort Type;
	ubyte StorageClass;
	ubyte NumberOfAuxSymbols;
}
static assert(mscoff_anon_symbol_table.sizeof == 18);

int adbg_object_mscoff_load(adbg_object_t *o) {
	o.format = AdbgObject.mscoff;
	
	// NOTE: No swapping is done because there is currently no sane way of detecting it
	
	return 0;
}