fasmsymfmt.h

#pragma once

#define FASMSYM_INCLUDED 1

/**
 * FASM Symbol File format descibed in this header.
 *
 *  FASM Symbol File can be generated by a fasm call like: fasm -s test.sym test.asm test.exe
 *
 
 FASM Symbol File Format
 =======================
 [FASM Symbol File Header]
 [String Table]
 [Symbol Table]
 [Preprocessed Source]
 [Assembly Dump]
 [Section Names] (only in object file)

*/

//
// FASM Symbols File Header Format
//

// Object header within fasm symbols file header.
// Defines offset of the object and its length.
struct FASM_SYMHDR_OBJECT
{
	DWORD Offset;
	DWORD Length;
};

// Fasm Symbols Header Signature
#define FASM_SYM_SIGNATURE 0x1a736166 // 'fas\x1a'

// Fasm Symbols Header
typedef struct FASM_SYMHDR
{
	/* +0x00 */ DWORD dwSignature; // 0x1a736166 ('fas' + 0x1a)
	/* +0x04 */ BYTE bVerMajor;
	/* +0x05 */ BYTE bVerMinor;
	/* +0x06 */ WORD wHeaderLen; // sizeof(FASM_SYMHDR)
	/* +0x08 */ DWORD dwInputFileNameOffset;
	/* +0x0c */ DWORD dwOutputFileNameOffset;
	/* +0x10 */ FASM_SYMHDR_OBJECT StringTable;
	/* +0x18 */ FASM_SYMHDR_OBJECT SymbolTable;
	/* +0x20 */ FASM_SYMHDR_OBJECT PreprocessedSource;
	/* +0x28 */ FASM_SYMHDR_OBJECT AssemblyDump;
	/* +0x30 */ FASM_SYMHDR_OBJECT SectionNames;
	/* Length = 0x38 bytes */
} FASM_SYMHDR, *PFASM_SYMHDR;

// Symbol name in preprocessed source?
#define IS_FASM_SYMBOL_NAME_IN_PREPROCESSED_SOURCE(SYM) (((SYM)->SymbolNameOffset & 0x80000000) == 0)

// Offset of symbol name in preprocessed source
#define PREPROCESSED_SOURCE_SYMBOL_NAME_OFFSET(SYM) ((SYM)->SymbolNameOffset & 0x3fffffff)

// Is symbol anonymous?
#define IS_FASM_SYMBOL_ANONYMOUS(SYM) ((SYM)->SymbolNameOffset == 0)

// Is symbol name in string table?
#define IS_FASM_SYMBOL_NAME_IN_STRING_TABLE(SYM) (((SYM)->SymbolNameOffset & 0x80000000) == 0x80000000)

// String table offset of the symbol name
#define STRING_TABLE_SYMBOL_NAME_OFFSET(SYM) ((SYM)->SymbolNameOffset & 0x3fffffff)

//
// Pascal String
//

#pragma pack(push, 1)
typedef struct PASCAL_STRING
{
	BYTE Length;
	BYTE String[1];
} PASCAL_STRING, *PPASCAL_STRING;
#pragma pack(pop)

//
// Fasm Symbol Flags
//

#define FASM_SYMBOL_DEFINED                 0x0001
#define FASM_SYMBOL_ASSEMBLY_TIME_VAR       0x0002
#define FASM_SYMBOL_NOT_FORWARD_REFERENCED  0x0004
#define FASM_SYMBOL_USED                    0x0008
#define FASM_SYMBOL_PREDICTED_USE           0x0010
#define FASM_SYMBOL_PREDICTED_USE_RES       0x0020
#define FASM_SYMBOL_PREDICTED_DEFINITION    0x0040
#define FASM_SYMBOL_PREDICTED_DEFINITION_RES 0x0080
#define FASM_SYMBOL_OPTIMIZATION_ADJ_APPLIED 0x0100
#define FASM_SYMBOL_RESERVED_BITS           0xfe00
#define FASM_SYMBOL_FLAGS_VALID(SYM) (((SYM)->Flags & FASM_SYMBOL_RESERVED_BITS) == 0)

//
// Fasm Symbol Types
//

#define FASM_SYMBOL_TYPE_ABSOLUTE           0     // Absolute Value
#define FASM_SYMBOL_TYPE_RELOC_SEG_ADDR     1     // Relocatable segment adddress (MZ)
#define FASM_SYMBOL_TYPE_RELOC32            2     // Relocatable 32-bit address
#define FASM_SYMBOL_TYPE_RELOC_REL32        3     // Relocatable relative 32-bit address (internal)
#define FASM_SYMBOL_TYPE_RELOC64            4     // Relocatable 64-bit address
#define FASM_SYMBOL_TYPE_ELF_GREL32         5     // (ELF only) GOT-relative 32-bit address
#define FASM_SYMBOL_TYPE_ELF_ADDR32_OF_PLT  6     // (ELF only) 32-bit address of PLT entry
#define FASM_SYMBOL_TYPE_ELF_RELADDR32_OF_PLT 7   // (ELF only) Relative 32-bit address of PLT entry (internal)
#define FASM_SYMBOL_TYPE_MAX 7
#define FASM_SYMBOL_TYPE_VALID(t) ((t) <= FASM_SYMBOL_TYPE_MAX)

// Address of first symbol
#define FASM_FIRST_SYMBOL(HDR) ((PFASM_SYMBOL)((PCHAR)(HDR) + (HDR)->SymbolTable.Offset))
#define FASM_SYMBOL_TABLE(HDR) FASM_FIRST_SYMBOL(HDR)

// Address of first string table
#define FASM_STRING_TABLE(HDR) ((PSZ)(HDR) + (HDR)->StringTable.Offset)

// Address of first preprocessed source element
#define FASM_PREPROCESSED_SOURCE(HDR) ((PSZ)(HDR) + (HDR)->PreprocessedSource.Offset)
#define FASM_FIRST_PSLINE(HDR) ((PFASM_SYM_LINE)FASM_PREPROCESSED_SOURCE(HDR))

// First row of assembly dump
#define FASM_FIRST_ASMDUMP_ROW(HDR)  ((PFASM_ASMDUMP_ROW)((PSZ)(HDR) + (HDR)->AssemblyDump.Offset))

// Address of DWORD[] array with offsets (in ST) of sections
#define FASM_SECTION_NAMES(HDR) ((PDWORD)((PSZ)(HDR) + (HDR)->SectionNames.Offset))

//
// Fasm Symbol
//

union FASM_SECTION_OR_EXTERNAL_SYMBOL_REF
{
	DWORD RawValue;
	struct {
		DWORD SectionIndex : 30;
		DWORD ReservedBit1 : 1;
		DWORD RelativeToExternal : 1; // =0 - relative to section
	};
	struct {
		DWORD ExternalSymNameOffset : 30; // in string table
		DWORD ReservedBit2 : 1;
		DWORD RelativeToExternal : 1; // =1 - relative to external symbol
	};
};

typedef struct FASM_SYMBOL
{
	/* +0x00 */ ULONGLONG Value;
	/* +0x08 */ WORD Flags;
	/* +0x0a */ BYTE SizeOfData;
	/* +0x0b */ BYTE Type;
	/* +0x0c */ DWORD ExtendedSIB;
	/* +0x10 */ WORD LastPassDefined;
	/* +0x12 */ WORD LastPassUsed;
	/* +0x14 */ FASM_SECTION_OR_EXTERNAL_SYMBOL_REF Ref;
	/* +0x18 */ DWORD SymbolNameOffset;
	/* +0x1c */ DWORD LineOffset; // in preprocessed source
	/* Length = 0x20 = 32 bytes */
} FASM_SYMBOL, *PFASM_SYMBOL;

//
// Preprocessed Source Line Format
//

typedef struct FASM_SYM_LINE
{
	union {
		/* +0x00 */ DWORD FileNameOffset; // ASCIIZ string or 0
		/* +0x00 */ DWORD MacroNameOffset; // Within the PS, pascal string.
	};
	/* +0x04 */ DWORD LineNumber : 30;
	/* +0x04 */ DWORD ReservedBit : 1;
	/* +0x04 */ DWORD MacroGenerated : 1;
	union {
		/* +0x08 */ DWORD SourceFilePosition;
		/* +0x08 */ DWORD MacroInvokedLineOffset;
	};
	/* +0x0c */ DWORD InMacroLineOffset; // only if MacroGenerated=1
#pragma warning(disable:4200)
	/* +0x10 (?) The tokenized contents of the line */ BYTE Contents[0];
#pragma warning(default:4200)
	/* Length = 0x10 + (?) bytes */
} FASM_SYM_LINE, *PFASM_SYM_LINE;

//
// FASM Row of the Assembly Dump Format
//

#pragma pack (push, 4)

typedef struct FASM_ASMDUMP_ROW
{
	/* +0x00 */ DWORD InOutputFileOffset;
	/* +0x04 */ DWORD LineOffset;
	/* +0x08 */ ULONGLONG AddressValue;
	/* +0x10 */ DWORD ExtendedSIB;
	/* +0x14 */ FASM_SECTION_OR_EXTERNAL_SYMBOL_REF Ref;
	/* +0x18 */ BYTE AddressType; // see Symbol Types
	/* +0x19 */ BYTE CodeType; // 16, 32 or 64
	/* +0x1a */ WORD InVirtualBlock : 1;
	/* +0x00 */ WORD NotIncludedInOutput : 1;
	/* +0x00 */ WORD ReservedBits : 14;
	/* Length = 0x1c = 28 bytes*/
} FASM_ASMDUMP_ROW, *PFASM_ASMDUMP_ROW;

#pragma pack (pop)