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 package obj 6 7 // This file defines the IDs for PCDATA and FUNCDATA instructions 8 // in Go binaries. It is included by assembly sources, so it must 9 // be written using #defines. 10 // 11 // The Go compiler also #includes this file, for now. 12 // 13 // symtab.go also contains a copy of these constants. 14 15 // Pseudo-assembly statements. 16 17 // GO_ARGS, GO_RESULTS_INITIALIZED, and NO_LOCAL_POINTERS are macros 18 // that communicate to the runtime information about the location and liveness 19 // of pointers in an assembly function's arguments, results, and stack frame. 20 // This communication is only required in assembly functions that make calls 21 // to other functions that might be preempted or grow the stack. 22 // NOSPLIT functions that make no calls do not need to use these macros. 23 24 // GO_ARGS indicates that the Go prototype for this assembly function 25 // defines the pointer map for the function's arguments. 26 // GO_ARGS should be the first instruction in a function that uses it. 27 // It can be omitted if there are no arguments at all. 28 // GO_ARGS is inserted implicitly by the linker for any function 29 // that also has a Go prototype and therefore is usually not necessary 30 // to write explicitly. 31 32 // GO_RESULTS_INITIALIZED indicates that the assembly function 33 // has initialized the stack space for its results and that those results 34 // should be considered live for the remainder of the function. 35 36 // NO_LOCAL_POINTERS indicates that the assembly function stores 37 // no pointers to heap objects in its local stack variables. 38 39 // ArgsSizeUnknown is set in Func.argsize to mark all functions 40 // whose argument size is unknown (C vararg functions, and 41 // assembly code without an explicit specification). 42 // This value is generated by the compiler, assembler, or linker. 43 const ( 44 PCDATA_StackMapIndex = 0 45 FUNCDATA_ArgsPointerMaps = 0 46 FUNCDATA_LocalsPointerMaps = 1 47 ArgsSizeUnknown = -0x80000000 48 ) 49
