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      1 // Derived from Inferno utils/6l/l.h and related files.
      2 // https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/l.h
      3 //
      4 //	Copyright  1994-1999 Lucent Technologies Inc.  All rights reserved.
      5 //	Portions Copyright  1995-1997 C H Forsyth (forsyth (a] terzarima.net)
      6 //	Portions Copyright  1997-1999 Vita Nuova Limited
      7 //	Portions Copyright  2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
      8 //	Portions Copyright  2004,2006 Bruce Ellis
      9 //	Portions Copyright  2005-2007 C H Forsyth (forsyth (a] terzarima.net)
     10 //	Revisions Copyright  2000-2007 Lucent Technologies Inc. and others
     11 //	Portions Copyright  2009 The Go Authors. All rights reserved.
     12 //
     13 // Permission is hereby granted, free of charge, to any person obtaining a copy
     14 // of this software and associated documentation files (the "Software"), to deal
     15 // in the Software without restriction, including without limitation the rights
     16 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     17 // copies of the Software, and to permit persons to whom the Software is
     18 // furnished to do so, subject to the following conditions:
     19 //
     20 // The above copyright notice and this permission notice shall be included in
     21 // all copies or substantial portions of the Software.
     22 //
     23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     24 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     25 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
     26 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     27 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     28 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     29 // THE SOFTWARE.
     30 
     31 package sym
     32 
     33 // A SymKind describes the kind of memory represented by a symbol.
     34 type SymKind uint8
     35 
     36 // Defined SymKind values.
     37 //
     38 // TODO(rsc): Give idiomatic Go names.
     39 //go:generate stringer -type=SymKind
     40 const (
     41 	Sxxx SymKind = iota
     42 	STEXT
     43 	SELFRXSECT
     44 
     45 	// Read-only sections.
     46 	STYPE
     47 	SSTRING
     48 	SGOSTRING
     49 	SGOFUNC
     50 	SGCBITS
     51 	SRODATA
     52 	SFUNCTAB
     53 
     54 	SELFROSECT
     55 	SMACHOPLT
     56 
     57 	// Read-only sections with relocations.
     58 	//
     59 	// Types STYPE-SFUNCTAB above are written to the .rodata section by default.
     60 	// When linking a shared object, some conceptually "read only" types need to
     61 	// be written to by relocations and putting them in a section called
     62 	// ".rodata" interacts poorly with the system linkers. The GNU linkers
     63 	// support this situation by arranging for sections of the name
     64 	// ".data.rel.ro.XXX" to be mprotected read only by the dynamic linker after
     65 	// relocations have applied, so when the Go linker is creating a shared
     66 	// object it checks all objects of the above types and bumps any object that
     67 	// has a relocation to it to the corresponding type below, which are then
     68 	// written to sections with appropriate magic names.
     69 	STYPERELRO
     70 	SSTRINGRELRO
     71 	SGOSTRINGRELRO
     72 	SGOFUNCRELRO
     73 	SGCBITSRELRO
     74 	SRODATARELRO
     75 	SFUNCTABRELRO
     76 
     77 	// Part of .data.rel.ro if it exists, otherwise part of .rodata.
     78 	STYPELINK
     79 	SITABLINK
     80 	SSYMTAB
     81 	SPCLNTAB
     82 
     83 	// Writable sections.
     84 	SELFSECT
     85 	SMACHO
     86 	SMACHOGOT
     87 	SWINDOWS
     88 	SELFGOT
     89 	SNOPTRDATA
     90 	SINITARR
     91 	SDATA
     92 	SBSS
     93 	SNOPTRBSS
     94 	STLSBSS
     95 	SXREF
     96 	SMACHOSYMSTR
     97 	SMACHOSYMTAB
     98 	SMACHOINDIRECTPLT
     99 	SMACHOINDIRECTGOT
    100 	SFILEPATH
    101 	SCONST
    102 	SDYNIMPORT
    103 	SHOSTOBJ
    104 	SDWARFSECT
    105 	SDWARFINFO
    106 	SDWARFRANGE
    107 	SDWARFLOC
    108 )
    109 
    110 // AbiSymKindToSymKind maps values read from object files (which are
    111 // of type cmd/internal/objabi.SymKind) to values of type SymKind.
    112 var AbiSymKindToSymKind = [...]SymKind{
    113 	Sxxx,
    114 	STEXT,
    115 	SRODATA,
    116 	SNOPTRDATA,
    117 	SDATA,
    118 	SBSS,
    119 	SNOPTRBSS,
    120 	STLSBSS,
    121 	SDWARFINFO,
    122 	SDWARFRANGE,
    123 	SDWARFLOC,
    124 }
    125 
    126 // ReadOnly are the symbol kinds that form read-only sections. In some
    127 // cases, if they will require relocations, they are transformed into
    128 // rel-ro sections using relROMap.
    129 var ReadOnly = []SymKind{
    130 	STYPE,
    131 	SSTRING,
    132 	SGOSTRING,
    133 	SGOFUNC,
    134 	SGCBITS,
    135 	SRODATA,
    136 	SFUNCTAB,
    137 }
    138 
    139 // RelROMap describes the transformation of read-only symbols to rel-ro
    140 // symbols.
    141 var RelROMap = map[SymKind]SymKind{
    142 	STYPE:     STYPERELRO,
    143 	SSTRING:   SSTRINGRELRO,
    144 	SGOSTRING: SGOSTRINGRELRO,
    145 	SGOFUNC:   SGOFUNCRELRO,
    146 	SGCBITS:   SGCBITSRELRO,
    147 	SRODATA:   SRODATARELRO,
    148 	SFUNCTAB:  SFUNCTABRELRO,
    149 }
    150