...
Text file
src/runtime/funcdata.h
Documentation: runtime
1// Copyright 2013 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// This file defines the IDs for PCDATA and FUNCDATA instructions
6// in Go binaries. It is included by assembly sources, so it must
7// be written using #defines.
8//
9// These must agree with symtab.go and ../cmd/internal/objabi/funcdata.go.
10
11#define PCDATA_UnsafePoint 0
12#define PCDATA_StackMapIndex 1
13#define PCDATA_InlTreeIndex 2
14
15#define FUNCDATA_ArgsPointerMaps 0 /* garbage collector blocks */
16#define FUNCDATA_LocalsPointerMaps 1
17#define FUNCDATA_StackObjects 2
18#define FUNCDATA_InlTree 3
19#define FUNCDATA_OpenCodedDeferInfo 4 /* info for func with open-coded defers */
20#define FUNCDATA_ArgInfo 5
21
22// Pseudo-assembly statements.
23
24// GO_ARGS, GO_RESULTS_INITIALIZED, and NO_LOCAL_POINTERS are macros
25// that communicate to the runtime information about the location and liveness
26// of pointers in an assembly function's arguments, results, and stack frame.
27// This communication is only required in assembly functions that make calls
28// to other functions that might be preempted or grow the stack.
29// NOSPLIT functions that make no calls do not need to use these macros.
30
31// GO_ARGS indicates that the Go prototype for this assembly function
32// defines the pointer map for the function's arguments.
33// GO_ARGS should be the first instruction in a function that uses it.
34// It can be omitted if there are no arguments at all.
35// GO_ARGS is inserted implicitly by the linker for any function whose
36// name starts with a middle-dot and that also has a Go prototype; it
37// is therefore usually not necessary to write explicitly.
38#define GO_ARGS FUNCDATA $FUNCDATA_ArgsPointerMaps, go_args_stackmap(SB)
39
40// GO_RESULTS_INITIALIZED indicates that the assembly function
41// has initialized the stack space for its results and that those results
42// should be considered live for the remainder of the function.
43#define GO_RESULTS_INITIALIZED PCDATA $PCDATA_StackMapIndex, $1
44
45// NO_LOCAL_POINTERS indicates that the assembly function stores
46// no pointers to heap objects in its local stack variables.
47#define NO_LOCAL_POINTERS FUNCDATA $FUNCDATA_LocalsPointerMaps, runtime·no_pointers_stackmap(SB)
48
49// ArgsSizeUnknown is set in Func.argsize to mark all functions
50// whose argument size is unknown (C vararg functions, and
51// assembly code without an explicit specification).
52// This value is generated by the compiler, assembler, or linker.
53#define ArgsSizeUnknown 0x80000000
View as plain text