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Diffstat (limited to 'src/cmd/internal/objabi/doc.go')
| -rw-r--r-- | src/cmd/internal/objabi/doc.go | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/src/cmd/internal/objabi/doc.go b/src/cmd/internal/objabi/doc.go deleted file mode 100644 index 08e922b11f..0000000000 --- a/src/cmd/internal/objabi/doc.go +++ /dev/null @@ -1,122 +0,0 @@ -// Copyright 2013 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. - -// NOTE: There are *three* independent implementations of this object -// file format in the Go source tree: -// -// - cmd/internal/goobj/read.go (used by cmd/addr2line, cmd/nm, cmd/objdump, cmd/pprof) -// - cmd/internal/obj/objfile.go (used by cmd/asm and cmd/compile) -// - cmd/link/internal/objfile.go (used by cmd/link) -// -// When changing the object file format, remember to change all three. - -// Originally, Go object files were Plan 9 object files, but no longer. -// Now they are more like standard object files, in that each symbol is defined -// by an associated memory image (bytes) and a list of relocations to apply -// during linking. We do not (yet?) use a standard file format, however. -// For now, the format is chosen to be as simple as possible to read and write. -// It may change for reasons of efficiency, or we may even switch to a -// standard file format if there are compelling benefits to doing so. -// See golang.org/s/go13linker for more background. -// -// The file format is: -// -// - magic header: "\x00go114ld" -// - byte 1 - version number -// - sequence of strings giving dependencies (imported packages) -// - empty string (marks end of sequence) -// - number of entries in the following sequence -// - sequence of filename strings to generate debug information -// - sequence of symbol references used by the defined symbols -// - byte 0xff (marks end of sequence) -// - sequence of integer lengths: -// - total data length -// - total number of relocations -// - total number of pcdata -// - total number of automatics -// - total number of funcdata -// - total number of files -// - data, the content of the defined symbols -// - sequence of defined symbols -// - byte 0xff (marks end of sequence) -// - magic footer: "\xffgo114ld" -// -// All integers are stored in a zigzag varint format. -// See golang.org/s/go12symtab for a definition. -// -// Data blocks and strings are both stored as an integer -// followed by that many bytes. -// -// A symbol reference is a string name followed by an ABI or -1 for static. -// -// A symbol points to other symbols using an index into the symbol -// reference sequence. Index 0 corresponds to a nil symbol pointer. -// In the symbol layout described below "symref index" stands for this -// index. -// -// Each symbol is laid out as the following fields: -// -// - byte 0xfe (sanity check for synchronization) -// - type [byte] -// - name & ABI [symref index] -// - flags [int] -// 1<<0 dupok -// 1<<1 local -// 1<<2 add to typelink table -// - size [int] -// - gotype [symref index] -// - p [data block] -// - nr [int] -// - r [nr relocations, sorted by off] -// -// If type == STEXT, there are a few more fields: -// -// - args [int] -// - locals [int] -// - nosplit [int] -// - flags [int] -// 1<<0 leaf -// 1<<1 C function -// 1<<2 function may call reflect.Type.Method -// 1<<3 function compiled with -shared -// - nlocal [int] -// - local [nlocal automatics] -// - pcln [pcln table] -// -// Each relocation has the encoding: -// -// - off [int] -// - siz [int] -// - type [int] -// - add [int] -// - sym [symref index] -// -// Each local has the encoding: -// -// - asym [symref index] -// - offset [int] -// - type [int] -// - gotype [symref index] -// -// The pcln table has the encoding: -// -// - pcsp [data block] -// - pcfile [data block] -// - pcline [data block] -// - pcinline [data block] -// - npcdata [int] -// - pcdata [npcdata data blocks] -// - nfuncdata [int] -// - funcdata [nfuncdata symref index] -// - funcdatasym [nfuncdata ints] -// - nfile [int] -// - file [nfile symref index] -// - ninlinedcall [int] -// - inlinedcall [ninlinedcall int symref int symref] -// -// The file layout and meaning of type integers are architecture-independent. -// -// TODO(rsc): The file format is good for a first pass but needs work. -// - There are SymID in the object file that should really just be strings. -package objabi |