实现基础web服务器

vendor/github.com/bytedance/sonic/loader/funcdata.go

@@ -0,0 +1,144 @@
+/**
+ * Copyright 2023 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package loader
+
+import (
+    `encoding`
+    `encoding/binary`
+    `fmt`
+    `reflect`
+    `strings`
+    `sync`
+    `unsafe`
+)
+
+const (
+    _MinLC uint8 = 1
+    _PtrSize uint8 = 8
+)
+
+const (
+    _N_FUNCDATA = 8
+    _INVALID_FUNCDATA_OFFSET = ^uint32(0)
+    _FUNC_SIZE = unsafe.Sizeof(_func{})
+    
+    _MINFUNC = 16 // minimum size for a function
+    _BUCKETSIZE    = 256 * _MINFUNC
+    _SUBBUCKETS    = 16
+    _SUB_BUCKETSIZE = _BUCKETSIZE / _SUBBUCKETS
+)
+
+// PCDATA and FUNCDATA table indexes.
+//
+// See funcdata.h and $GROOT/src/cmd/internal/objabi/funcdata.go.
+const (
+    _FUNCDATA_ArgsPointerMaps    = 0
+    _FUNCDATA_LocalsPointerMaps  = 1
+    _FUNCDATA_StackObjects       = 2
+    _FUNCDATA_InlTree            = 3
+    _FUNCDATA_OpenCodedDeferInfo = 4
+    _FUNCDATA_ArgInfo            = 5
+    _FUNCDATA_ArgLiveInfo        = 6
+    _FUNCDATA_WrapInfo           = 7
+
+    // ArgsSizeUnknown is set in Func.argsize to mark all functions
+    // whose argument size is unknown (C vararg functions, and
+    // assembly code without an explicit specification).
+    // This value is generated by the compiler, assembler, or linker.
+    ArgsSizeUnknown = -0x80000000
+)
+
+// moduledata used to cache the funcdata and findfuncbucket of one module
+var moduleCache = struct {
+    m map[*moduledata][]byte
+    sync.Mutex
+}{
+    m: make(map[*moduledata][]byte),
+}
+
+// Func contains information about a function.
+type Func struct {
+    ID          uint8  // see runtime/symtab.go
+    Flag        uint8  // see runtime/symtab.go
+    ArgsSize    int32  // args byte size
+    EntryOff    uint32 // start pc, offset to moduledata.text
+    TextSize    uint32 // size of func text
+    DeferReturn uint32 // offset of start of a deferreturn call instruction from entry, if any.
+    FileIndex   uint32 // index into filetab 
+    Name        string // name of function
+
+    // PC data
+    Pcsp            *Pcdata // PC -> SP delta
+    Pcfile          *Pcdata // PC -> file index
+    Pcline          *Pcdata // PC -> line number
+    PcUnsafePoint   *Pcdata // PC -> unsafe point, must be PCDATA_UnsafePointSafe or PCDATA_UnsafePointUnsafe
+    PcStackMapIndex *Pcdata // PC -> stack map index, relative to ArgsPointerMaps and LocalsPointerMaps
+    PcInlTreeIndex  *Pcdata // PC -> inlining tree index, relative to InlTree
+    PcArgLiveIndex  *Pcdata // PC -> arg live index, relative to ArgLiveInfo
+    
+    // Func data, must implement encoding.BinaryMarshaler
+    ArgsPointerMaps    encoding.BinaryMarshaler // concrete type: *StackMap
+    LocalsPointerMaps  encoding.BinaryMarshaler // concrete type: *StackMap
+    StackObjects       encoding.BinaryMarshaler
+    InlTree            encoding.BinaryMarshaler
+    OpenCodedDeferInfo encoding.BinaryMarshaler
+    ArgInfo            encoding.BinaryMarshaler
+    ArgLiveInfo        encoding.BinaryMarshaler
+    WrapInfo           encoding.BinaryMarshaler
+}
+
+func getOffsetOf(data interface{}, field string) uintptr {
+    t := reflect.TypeOf(data)
+    fv, ok := t.FieldByName(field)
+    if !ok {
+        panic(fmt.Sprintf("field %s not found in struct %s", field, t.Name()))
+    }
+    return fv.Offset
+}
+
+func rnd(v int64, r int64) int64 {
+    if r <= 0 {
+        return v
+    }
+    v += r - 1
+    c := v % r
+    if c < 0 {
+        c += r
+    }
+    v -= c
+    return v
+}
+
+var (
+    byteOrder binary.ByteOrder = binary.LittleEndian
+)
+
+func funcNameParts(name string) (string, string, string) {
+    i := strings.IndexByte(name, '[')
+    if i < 0 {
+        return name, "", ""
+    }
+    // TODO: use LastIndexByte once the bootstrap compiler is >= Go 1.5.
+    j := len(name) - 1
+    for j > i && name[j] != ']' {
+        j--
+    }
+    if j <= i {
+        return name, "", ""
+    }
+    return name[:i], "[...]", name[j+1:]
+}