NAME

NXGetAllArchInfos, NXGetLocalArchInfo, NXGetArchInfoFromName, NXGetArchInfoFromCpuType, NXFindBestFatArch, NXCombineCpuSubtypes − get architecture information

SYNOPSIS

#include <mach-o/arch.h>
extern const NXArchInfo ∗NXGetAllArchInfos(void);
extern const NXArchInfo ∗NXGetLocalArchInfo(void);
extern const NXArchInfo ∗NXGetArchInfoFromName(const char ∗name);
extern const NXArchInfo ∗NXGetArchInfoFromCpuType(cpu_type_t cputype,
cpu_subtype_t cpusubtype);
extern struct fat_arch ∗NXFindBestFatArch(cpu_type_t cputype,
cpu_subtype_t cpusubtype,
struct fat_arch ∗fat_archs,
unsigned long nfat_archs);
extern cpu_subtype_t NXCombineCpuSubtypes(cpu_type_t cputype,
cpu_subtype_t cpusubtype1,
cpu_subtype_t cpusubtype2);

DESCRIPTION

These functions are intended for use in programs that have to deal with fat files or programs that can target multiple architectures.  Typically, a program will use a command-line argument that starts with −arch name, where this specifies an architecture.  These functions and data structures provide some help for processing architecture flags and then processing the contents of a fat file.

The structure NXArchInfo is defined in <mach-o/arch.h> as follows:

typedef struct {
const char ∗name;
cpu_type_t cputype;
cpu_subtype_t cpusubtype;
enum NXByteOrder byteorder;
const char ∗description;
} NXArchInfo;

It is used to hold the name of the architecture and the corresponding CPU type and CPU subtype, together with the architecture’s byte order and a brief description string. 

The currently known architectures are:

NameCPU TypeCPU SubtypeDescription
hppaCPU_TYPE_HPPACPU_SUBTYPE_HPPA_ALLHP-PA
i386CPU_TYPE_I386CPU_SUBTYPE_I386_ALLIntel 80x86
i860CPU_TYPE_I860CPU_SUBTYPE_I860_ALLIntel 860
m68kCPU_TYPE_MC680x0CPU_SUBTYPE_MC680x0_ALLMotorola 68K
m88kCPU_TYPE_MC88000CPU_SUBTYPE_MC88000_ALLMotorola 88K
m98kCPU_TYPE_MC98000CPU_SUBTYPE_MC98000_ALLPower PC
mipsCPU_TYPE_MIPSCPU_SUBTYPE_MIPS_ALLMIPS
sparcCPU_TYPE_SPARCCPU_SUBTYPE_SUN4_ALLSPARC
vaxCPU_TYPE_VAXCPU_SUBTYPE_VAX_ALLDEC VAX i486CPU_TYPE_I386CPU_SUBTYPE_486Intel 486
i486SXCPU_TYPE_I386CPU_SUBTYPE_486SXIntel 486SX
i586CPU_TYPE_I386CPU_SUBTYPE_586Intel 586
i586SXCPU_TYPE_I386CPU_SUBTYPE_586SXIntel 586SX
m68030CPU_TYPE_MC680x0CPU_SUBTYPE_MC68030_ONLYMotorola 68030
m68040CPU_TYPE_MC680x0CPU_SUBTYPE_MC68040Motorola 68040

The first set of entries are used for the architecture family.  The second set of entries are used for a specific architecture, when more than one specific architecture is supported in a family of architectures. 

NXGetAllArchInfos() returns a pointer to an array of all known NXArchInfo structures.  The last NXArchInfo is marked by a NULL name. 

NXGetLocalArchInfo() returns the NXArchInfo for the local host, or NULL if none is known. 

NXGetArchInfoFromName() and NXGetArchInfoFromCpuType() return the NXArchInfo from the architecture’s name or CPU type/CPU subtype combination.  A CPU subtype of CPU_SUBTYPE_MULTIPLE can be used to request the most general NXArchInfo known for the given CPU type.  NULL is returned if no matching NXArchInfo can be found. 

NXFindBestFatArch() is passed a CPU type and CPU subtype and a set of fat_arch structs.  It selects the best one that matches (if any), and returns a pointer to that fat_arch struct (or NULL).  The fat_arch structs must be in the host byte order and correct such that fat_archs really points to enough memory for nfat_arch structs.  It is possible that this routine could fail if new CPU types or CPU subtypes are added and an old version of this routine is used.  But if there is an exact match between the CPU type and CPU subtype and one of the fat_arch structs, this routine will always succeed. 

NXCombineCpuSubtypes() returns the resulting CPU subtype when combining two different CPU subtypes for the specified CPU type.  If the two CPU subtypes can’t be combined (the specific subtypes are mutually exclusive), −1 is returned, indicating it is an error to combine them.  This can also fail and return −1 if new CPU types or CPU subtypes are added and an old version of this routine is used.  But if the CPU subtypes are the same, they can always be combined and this routine will return the CPU subtype passed in.

NeXT Computer, Inc.  —  July 19, 1993