gtsocial-umbx

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funcdata.go (4341B)

      1 /**
      2  * Copyright 2023 ByteDance Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package loader
     18 
     19 import (
     20     `encoding`
     21     `encoding/binary`
     22     `fmt`
     23     `reflect`
     24     `strings`
     25     `sync`
     26     `unsafe`
     27 )
     28 
     29 const (
     30     _MinLC uint8 = 1
     31     _PtrSize uint8 = 8
     32 )
     33 
     34 const (
     35     _N_FUNCDATA = 8
     36     _INVALID_FUNCDATA_OFFSET = ^uint32(0)
     37     _FUNC_SIZE = unsafe.Sizeof(_func{})
     38     
     39     _MINFUNC = 16 // minimum size for a function
     40     _BUCKETSIZE    = 256 * _MINFUNC
     41     _SUBBUCKETS    = 16
     42     _SUB_BUCKETSIZE = _BUCKETSIZE / _SUBBUCKETS
     43 )
     44 
     45 // PCDATA and FUNCDATA table indexes.
     46 //
     47 // See funcdata.h and $GROOT/src/cmd/internal/objabi/funcdata.go.
     48 const (
     49     _FUNCDATA_ArgsPointerMaps    = 0
     50     _FUNCDATA_LocalsPointerMaps  = 1
     51     _FUNCDATA_StackObjects       = 2
     52     _FUNCDATA_InlTree            = 3
     53     _FUNCDATA_OpenCodedDeferInfo = 4
     54     _FUNCDATA_ArgInfo            = 5
     55     _FUNCDATA_ArgLiveInfo        = 6
     56     _FUNCDATA_WrapInfo           = 7
     57 
     58     // ArgsSizeUnknown is set in Func.argsize to mark all functions
     59     // whose argument size is unknown (C vararg functions, and
     60     // assembly code without an explicit specification).
     61     // This value is generated by the compiler, assembler, or linker.
     62     ArgsSizeUnknown = -0x80000000
     63 )
     64 
     65 // moduledata used to cache the funcdata and findfuncbucket of one module
     66 var moduleCache = struct {
     67     m map[*moduledata][]byte
     68     sync.Mutex
     69 }{
     70     m: make(map[*moduledata][]byte),
     71 }
     72 
     73 // Func contains information about a function.
     74 type Func struct {
     75     ID          uint8  // see runtime/symtab.go
     76     Flag        uint8  // see runtime/symtab.go
     77     ArgsSize    int32  // args byte size
     78     EntryOff    uint32 // start pc, offset to moduledata.text
     79     TextSize    uint32 // size of func text
     80     DeferReturn uint32 // offset of start of a deferreturn call instruction from entry, if any.
     81     FileIndex   uint32 // index into filetab 
     82     Name        string // name of function
     83 
     84     // PC data
     85     Pcsp            *Pcdata // PC -> SP delta
     86     Pcfile          *Pcdata // PC -> file index
     87     Pcline          *Pcdata // PC -> line number
     88     PcUnsafePoint   *Pcdata // PC -> unsafe point, must be PCDATA_UnsafePointSafe or PCDATA_UnsafePointUnsafe
     89     PcStackMapIndex *Pcdata // PC -> stack map index, relative to ArgsPointerMaps and LocalsPointerMaps
     90     PcInlTreeIndex  *Pcdata // PC -> inlining tree index, relative to InlTree
     91     PcArgLiveIndex  *Pcdata // PC -> arg live index, relative to ArgLiveInfo
     92     
     93     // Func data, must implement encoding.BinaryMarshaler
     94     ArgsPointerMaps    encoding.BinaryMarshaler // concrete type: *StackMap
     95     LocalsPointerMaps  encoding.BinaryMarshaler // concrete type: *StackMap
     96     StackObjects       encoding.BinaryMarshaler
     97     InlTree            encoding.BinaryMarshaler
     98     OpenCodedDeferInfo encoding.BinaryMarshaler
     99     ArgInfo            encoding.BinaryMarshaler
    100     ArgLiveInfo        encoding.BinaryMarshaler
    101     WrapInfo           encoding.BinaryMarshaler
    102 }
    103 
    104 func getOffsetOf(data interface{}, field string) uintptr {
    105     t := reflect.TypeOf(data)
    106     fv, ok := t.FieldByName(field)
    107     if !ok {
    108         panic(fmt.Sprintf("field %s not found in struct %s", field, t.Name()))
    109     }
    110     return fv.Offset
    111 }
    112 
    113 func rnd(v int64, r int64) int64 {
    114     if r <= 0 {
    115         return v
    116     }
    117     v += r - 1
    118     c := v % r
    119     if c < 0 {
    120         c += r
    121     }
    122     v -= c
    123     return v
    124 }
    125 
    126 var (
    127     byteOrder binary.ByteOrder = binary.LittleEndian
    128 )
    129 
    130 func funcNameParts(name string) (string, string, string) {
    131     i := strings.IndexByte(name, '[')
    132     if i < 0 {
    133         return name, "", ""
    134     }
    135     // TODO: use LastIndexByte once the bootstrap compiler is >= Go 1.5.
    136     j := len(name) - 1
    137     for j > i && name[j] != ']' {
    138         j--
    139     }
    140     if j <= i {
    141         return name, "", ""
    142     }
    143     return name[:i], "[...]", name[j+1:]
    144 }