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_RegMapIndex 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_RegPointerMaps 2
18 #define FUNCDATA_StackObjects 3
19 #define FUNCDATA_InlTree 4
20 #define FUNCDATA_OpenCodedDeferInfo 5 /* info for func with open-coded defers */
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
36 // that also has a Go prototype and therefore is usually not necessary
37 // 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
54