1// Derived from Inferno utils/6l/l.h and related files.
2// https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/l.h
3//
4//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
5//	Portions Copyright © 1995-1997 C H Forsyth ([email protected])
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 ([email protected])
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
31package sym
32
33import "cmd/internal/objabi"
34
35// A SymKind describes the kind of memory represented by a symbol.
36type SymKind uint8
37
38// Defined SymKind values.
39//
40// TODO(rsc): Give idiomatic Go names.
41//
42//go:generate stringer -type=SymKind
43const (
44	Sxxx SymKind = iota
45	STEXT
46	SELFRXSECT
47	SMACHOPLT
48
49	// Read-only sections.
50	STYPE
51	SSTRING
52	SGOSTRING
53	SGOFUNC
54	SGCBITS
55	SRODATA
56	SFUNCTAB
57
58	SELFROSECT
59
60	// Read-only sections with relocations.
61	//
62	// Types STYPE-SFUNCTAB above are written to the .rodata section by default.
63	// When linking a shared object, some conceptually "read only" types need to
64	// be written to by relocations and putting them in a section called
65	// ".rodata" interacts poorly with the system linkers. The GNU linkers
66	// support this situation by arranging for sections of the name
67	// ".data.rel.ro.XXX" to be mprotected read only by the dynamic linker after
68	// relocations have applied, so when the Go linker is creating a shared
69	// object it checks all objects of the above types and bumps any object that
70	// has a relocation to it to the corresponding type below, which are then
71	// written to sections with appropriate magic names.
72	STYPERELRO
73	SSTRINGRELRO
74	SGOSTRINGRELRO
75	SGOFUNCRELRO
76	SGCBITSRELRO
77	SRODATARELRO
78	SFUNCTABRELRO
79	SELFRELROSECT
80
81	// Part of .data.rel.ro if it exists, otherwise part of .rodata.
82	STYPELINK
83	SITABLINK
84	SSYMTAB
85	SPCLNTAB
86
87	// Writable sections.
88	SFirstWritable
89	SBUILDINFO
90	SELFSECT
91	SMACHO
92	SMACHOGOT
93	SWINDOWS
94	SELFGOT
95	SNOPTRDATA
96	SINITARR
97	SDATA
98	SXCOFFTOC
99	SBSS
100	SNOPTRBSS
101	SLIBFUZZER_8BIT_COUNTER
102	SCOVERAGE_COUNTER
103	SCOVERAGE_AUXVAR
104	STLSBSS
105	SXREF
106	SMACHOSYMSTR
107	SMACHOSYMTAB
108	SMACHOINDIRECTPLT
109	SMACHOINDIRECTGOT
110	SFILEPATH
111	SDYNIMPORT
112	SHOSTOBJ
113	SUNDEFEXT // Undefined symbol for resolution by external linker
114
115	// Sections for debugging information
116	SDWARFSECT
117	// DWARF symbol types
118	SDWARFCUINFO
119	SDWARFCONST
120	SDWARFFCN
121	SDWARFABSFCN
122	SDWARFTYPE
123	SDWARFVAR
124	SDWARFRANGE
125	SDWARFLOC
126	SDWARFLINES
127
128	// SEH symbol types
129	SSEHUNWINDINFO
130	SSEHSECT
131)
132
133// AbiSymKindToSymKind maps values read from object files (which are
134// of type cmd/internal/objabi.SymKind) to values of type SymKind.
135var AbiSymKindToSymKind = [...]SymKind{
136	objabi.Sxxx:                    Sxxx,
137	objabi.STEXT:                   STEXT,
138	objabi.SRODATA:                 SRODATA,
139	objabi.SNOPTRDATA:              SNOPTRDATA,
140	objabi.SDATA:                   SDATA,
141	objabi.SBSS:                    SBSS,
142	objabi.SNOPTRBSS:               SNOPTRBSS,
143	objabi.STLSBSS:                 STLSBSS,
144	objabi.SDWARFCUINFO:            SDWARFCUINFO,
145	objabi.SDWARFCONST:             SDWARFCONST,
146	objabi.SDWARFFCN:               SDWARFFCN,
147	objabi.SDWARFABSFCN:            SDWARFABSFCN,
148	objabi.SDWARFTYPE:              SDWARFTYPE,
149	objabi.SDWARFVAR:               SDWARFVAR,
150	objabi.SDWARFRANGE:             SDWARFRANGE,
151	objabi.SDWARFLOC:               SDWARFLOC,
152	objabi.SDWARFLINES:             SDWARFLINES,
153	objabi.SLIBFUZZER_8BIT_COUNTER: SLIBFUZZER_8BIT_COUNTER,
154	objabi.SCOVERAGE_COUNTER:       SCOVERAGE_COUNTER,
155	objabi.SCOVERAGE_AUXVAR:        SCOVERAGE_AUXVAR,
156	objabi.SSEHUNWINDINFO:          SSEHUNWINDINFO,
157}
158
159// ReadOnly are the symbol kinds that form read-only sections. In some
160// cases, if they will require relocations, they are transformed into
161// rel-ro sections using relROMap.
162var ReadOnly = []SymKind{
163	STYPE,
164	SSTRING,
165	SGOSTRING,
166	SGOFUNC,
167	SGCBITS,
168	SRODATA,
169	SFUNCTAB,
170}
171
172// RelROMap describes the transformation of read-only symbols to rel-ro
173// symbols.
174var RelROMap = map[SymKind]SymKind{
175	STYPE:     STYPERELRO,
176	SSTRING:   SSTRINGRELRO,
177	SGOSTRING: SGOSTRINGRELRO,
178	SGOFUNC:   SGOFUNCRELRO,
179	SGCBITS:   SGCBITSRELRO,
180	SRODATA:   SRODATARELRO,
181	SFUNCTAB:  SFUNCTABRELRO,
182}
183
184// IsData returns true if the type is a data type.
185func (t SymKind) IsData() bool {
186	return t == SDATA || t == SNOPTRDATA || t == SBSS || t == SNOPTRBSS
187}
188
189func (t SymKind) IsDWARF() bool {
190	return t >= SDWARFSECT && t <= SDWARFLINES
191}
192