module.1.16.go

//go:build go1.16 && !go1.18
// +build go1.16,!go1.18

package goloader

import (
	"unsafe"
)

const magic uint32 = 0xFFFFFFFA

// pcHeader holds data used by the pclntab lookups.
type pcHeader struct {
	magic          uint32  // 0xFFFFFFFA
	pad1, pad2     uint8   // 0,0
	minLC          uint8   // min instruction size
	ptrSize        uint8   // size of a ptr in bytes
	nfunc          int     // number of functions in the module
	nfiles         uint    // number of entries in the file tab.
	funcnameOffset uintptr // offset to the funcnametab variable from pcHeader
	cuOffset       uintptr // offset to the cutab variable from pcHeader
	filetabOffset  uintptr // offset to the filetab variable from pcHeader
	pctabOffset    uintptr // offset to the pctab varible from pcHeader
	pclnOffset     uintptr // offset to the pclntab variable from pcHeader
}

// moduledata records information about the layout of the executable
// image. It is written by the linker. Any changes here must be
// matched changes to the code in cmd/link/internal/ld/symtab.go:symtab.
// moduledata is stored in statically allocated non-pointer memory;
// none of the pointers here are visible to the garbage collector.
type moduledata struct {
	pcHeader     *pcHeader
	funcnametab  []byte
	cutab        []uint32
	filetab      []byte
	pctab        []byte
	pclntable    []byte
	ftab         []functab
	findfunctab  uintptr
	minpc, maxpc uintptr

	text, etext           uintptr
	noptrdata, enoptrdata uintptr
	data, edata           uintptr
	bss, ebss             uintptr
	noptrbss, enoptrbss   uintptr
	end, gcdata, gcbss    uintptr
	types, etypes         uintptr

	textsectmap []textsect
	typelinks   []int32 // offsets from types
	itablinks   []*itab

	ptab []ptabEntry

	pluginpath string
	pkghashes  []modulehash

	modulename   string
	modulehashes []modulehash

	hasmain uint8 // 1 if module contains the main function, 0 otherwise

	gcdatamask, gcbssmask bitvector

	typemap map[typeOff]uintptr // offset to *_rtype in previous module

	bad bool // module failed to load and should be ignored

	next *moduledata
}

func initmodule(module *moduledata, linker *Linker) {
	module.pcHeader = (*pcHeader)(unsafe.Pointer(&(module.pclntable[0])))
	module.pcHeader.nfunc = len(module.ftab)
	module.pcHeader.nfiles = (uint)(len(module.filetab))
	module.funcnametab = module.pclntable
	module.pctab = module.pclntable
	module.cutab = linker.Filetab
	module.filetab = module.pclntable
	module.hasmain = 0
	module.bad = false
}