github.com/nikandfor/loc@v0.5.1/name_file_line_go1.12.go (about)

     1  //go:build nikandfor_loc_unsafe && !go1.16
     2  // +build nikandfor_loc_unsafe,!go1.16
     3  
     4  package loc
     5  
     6  import "unsafe"
     7  
     8  func (l PC) nameFileLine() (name, file string, line int) {
     9  	if l == 0 {
    10  		return
    11  	}
    12  
    13  	funcInfo := findfunc(l)
    14  	if funcInfo.entry == nil {
    15  		return
    16  	}
    17  
    18  	if uintptr(l) > *funcInfo.entry {
    19  		// We store the pc of the start of the instruction following
    20  		// the instruction in question (the call or the inline mark).
    21  		// This is done for historical reasons, and to make FuncForPC
    22  		// work correctly for entries in the result of runtime.Callers.
    23  		l--
    24  	}
    25  
    26  	name = funcname(funcInfo)
    27  	if inldata := funcdata(funcInfo, _FUNCDATA_InlTree); inldata != nil {
    28  		ix := pcdatavalue(funcInfo, _PCDATA_InlTreeIndex, l, nil)
    29  		if ix >= 0 {
    30  			inltree := (*[1 << 20]inlinedCall)(inldata)
    31  			// Note: entry is not modified. It always refers to a real frame, not an inlined one.
    32  			name = funcnameFromNameoff(funcInfo, inltree[ix].func_)
    33  			// File/line is already correct.
    34  			// TODO: remove file/line from InlinedCall?
    35  		}
    36  	}
    37  
    38  	file, line32 := funcline1(funcInfo, l, false)
    39  	line = int(line32)
    40  
    41  	return
    42  }
    43  
    44  //go:linkname findfunc runtime.findfunc
    45  func findfunc(pc PC) funcInfo
    46  
    47  //go:linkname funcline1 runtime.funcline1
    48  func funcline1(f funcInfo, targetpc PC, strict bool) (file string, line int32)
    49  
    50  //go:linkname funcname runtime.funcname
    51  func funcname(f funcInfo) string
    52  
    53  //go:linkname funcdata runtime.funcdata
    54  func funcdata(f funcInfo, i uint8) unsafe.Pointer
    55  
    56  //go:linkname pcdatavalue runtime.pcdatavalue
    57  func pcdatavalue(f funcInfo, table int32, targetpc PC, cache unsafe.Pointer) int32
    58  
    59  //go:linkname funcnameFromNameoff runtime.funcnameFromNameoff
    60  func funcnameFromNameoff(f funcInfo, nameoff int32) string