github.com/likebike/go--@v0.0.0-20190911215757-0bd925d16e96/go/src/runtime/funcdata.h (about)

     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/obj/funcdata.go.
    10  
    11  #define PCDATA_StackMapIndex 0
    12  #define PCDATA_InlTreeIndex 1
    13  
    14  #define FUNCDATA_ArgsPointerMaps 0 /* garbage collector blocks */
    15  #define FUNCDATA_LocalsPointerMaps 1
    16  #define FUNCDATA_InlTree 2
    17  
    18  // Pseudo-assembly statements.
    19  
    20  // GO_ARGS, GO_RESULTS_INITIALIZED, and NO_LOCAL_POINTERS are macros
    21  // that communicate to the runtime information about the location and liveness
    22  // of pointers in an assembly function's arguments, results, and stack frame.
    23  // This communication is only required in assembly functions that make calls
    24  // to other functions that might be preempted or grow the stack.
    25  // NOSPLIT functions that make no calls do not need to use these macros.
    26  
    27  // GO_ARGS indicates that the Go prototype for this assembly function
    28  // defines the pointer map for the function's arguments.
    29  // GO_ARGS should be the first instruction in a function that uses it.
    30  // It can be omitted if there are no arguments at all.
    31  // GO_ARGS is inserted implicitly by the linker for any function
    32  // that also has a Go prototype and therefore is usually not necessary
    33  // to write explicitly.
    34  #define GO_ARGS	FUNCDATA $FUNCDATA_ArgsPointerMaps, go_args_stackmap(SB)
    35  
    36  // GO_RESULTS_INITIALIZED indicates that the assembly function
    37  // has initialized the stack space for its results and that those results
    38  // should be considered live for the remainder of the function.
    39  #define GO_RESULTS_INITIALIZED	PCDATA $PCDATA_StackMapIndex, $1
    40  
    41  // NO_LOCAL_POINTERS indicates that the assembly function stores
    42  // no pointers to heap objects in its local stack variables.
    43  #define NO_LOCAL_POINTERS	FUNCDATA $FUNCDATA_LocalsPointerMaps, runtime·no_pointers_stackmap(SB)
    44  
    45  // ArgsSizeUnknown is set in Func.argsize to mark all functions
    46  // whose argument size is unknown (C vararg functions, and
    47  // assembly code without an explicit specification).
    48  // This value is generated by the compiler, assembler, or linker.
    49  #define ArgsSizeUnknown 0x80000000