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// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package abi
// A FuncFlag records bits about a function, passed to the runtime.
type FuncFlag uint8
const (
// FuncFlagTopFrame indicates a function that appears at the top of its stack.
// The traceback routine stop at such a function and consider that a
// successful, complete traversal of the stack.
// Examples of TopFrame functions include goexit, which appears
// at the top of a user goroutine stack, and mstart, which appears
// at the top of a system goroutine stack.
FuncFlagTopFrame FuncFlag = 1 << iota
// FuncFlagSPWrite indicates a function that writes an arbitrary value to SP
// (any write other than adding or subtracting a constant amount).
// The traceback routines cannot encode such changes into the
// pcsp tables, so the function traceback cannot safely unwind past
// SPWrite functions. Stopping at an SPWrite function is considered
// to be an incomplete unwinding of the stack. In certain contexts
// (in particular garbage collector stack scans) that is a fatal error.
FuncFlagSPWrite
// FuncFlagAsm indicates that a function was implemented in assembly.
FuncFlagAsm
)
// A FuncID identifies particular functions that need to be treated
// specially by the runtime.
// Note that in some situations involving plugins, there may be multiple
// copies of a particular special runtime function.
type FuncID uint8
const (
// If you add a FuncID, you probably also want to add an entry to the map in
// ../../cmd/internal/objabi/funcid.go
FuncIDNormal FuncID = iota // not a special function
FuncID_abort
FuncID_asmcgocall
FuncID_asyncPreempt
FuncID_cgocallback
FuncID_debugCallV2
FuncID_gcBgMarkWorker
FuncID_goexit
FuncID_gogo
FuncID_gopanic
FuncID_handleAsyncEvent
FuncID_mcall
FuncID_morestack
FuncID_mstart
FuncID_panicwrap
FuncID_rt0_go
FuncID_runfinq
FuncID_runtime_main
FuncID_sigpanic
FuncID_systemstack
FuncID_systemstack_switch
FuncIDWrapper // any autogenerated code (hash/eq algorithms, method wrappers, etc.)
)
// 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.
const ArgsSizeUnknown = -0x80000000
// IDs for PCDATA and FUNCDATA tables in Go binaries.
//
// These must agree with ../../../runtime/funcdata.h.
const (
PCDATA_UnsafePoint = 0
PCDATA_StackMapIndex = 1
PCDATA_InlTreeIndex = 2
PCDATA_ArgLiveIndex = 3
FUNCDATA_ArgsPointerMaps = 0
FUNCDATA_LocalsPointerMaps = 1
FUNCDATA_StackObjects = 2
FUNCDATA_InlTree = 3
FUNCDATA_OpenCodedDeferInfo = 4
FUNCDATA_ArgInfo = 5
FUNCDATA_ArgLiveInfo = 6
FUNCDATA_WrapInfo = 7
)
// Special values for the PCDATA_UnsafePoint table.
const (
UnsafePointSafe = -1 // Safe for async preemption
UnsafePointUnsafe = -2 // Unsafe for async preemption
// UnsafePointRestart1(2) apply on a sequence of instructions, within
// which if an async preemption happens, we should back off the PC
// to the start of the sequence when resuming.
// We need two so we can distinguish the start/end of the sequence
// in case that two sequences are next to each other.
UnsafePointRestart1 = -3
UnsafePointRestart2 = -4
// Like UnsafePointRestart1, but back to function entry if async preempted.
UnsafePointRestartAtEntry = -5
)