-
Notifications
You must be signed in to change notification settings - Fork 0
/
options.go
372 lines (332 loc) · 9.17 KB
/
options.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
// dcc - dependency-driven C/C++ compiler front end
//
// Copyright © A.Newman 2015.
//
// This source code is released under version 2 of the GNU Public License.
// See the file LICENSE for details.
//
package main
import (
"bufio"
"fmt"
"io"
"log"
"os"
"path/filepath"
"strings"
"time"
)
const (
includeDirective = "!include"
inheritDirective = "!inherit"
ifdefDirective = "!ifdef"
ifndefDirective = "!ifndef"
elseDirective = "!else"
endifDirective = "!endif"
errorDirective = "!error"
)
// Options represents a series of words and is used to represent
// compiler and linker options. Options are intended to be read from a
// file and act as a dependency to the build.
//
// An Options has a slice of strings, the option "values".
//
type Options struct {
Values []string // option values
Path string // associated file path
fileinfo os.FileInfo // actual options file info
mtime time.Time // options modtime, mutable
}
// NewOptions returns a new, empty, Options value
//
func NewOptions() *Options {
return &Options{
Values: make([]string, 0),
}
}
// FileInfo returns the receiver's os.FileInfo set when the
// receiver was successfully read from a file.
//
func (o *Options) FileInfo() os.FileInfo {
return o.fileinfo
}
// Len returns the number of values defined by the receiver.
//
func (o *Options) Len() int {
return len(o.Values)
}
// Empty returns true if the Options has no values
//
func (o *Options) Empty() bool {
return len(o.Values) == 0
}
// String returns a string representation of the receiver. This
// returns a space separated list of the options' Values.
//
func (o *Options) String() string {
return strings.Join(o.Values, " ")
}
// Changed updates the "modtime" of the receiver, to "now".
//
func (o *Options) Changed() {
o.mtime = time.Now()
}
// Append appends an option to the set of options. Note, Append does
// NOT modify the mtime of the receiver.
//
func (o *Options) Append(option string) {
o.Values = append(o.Values, option)
}
// Prepend inserts an option at the start of the set of options.
// Note, Prepend does NOT modify the mtime of the receiver.
//
func (o *Options) Prepend(option string) {
o.Values = append([]string{option}, o.Values...)
}
// SetModTime sets the receiver's modification time to the supplied
// value.
//
func (o *Options) SetModTime(t time.Time) {
o.mtime = t
}
// Return the options modification time.
//
func (o *Options) ModTime() time.Time {
return o.mtime
}
// SetFrom copies options from another Options leaving
// the receiver's Path unmodified.
//
func (o *Options) SetFrom(other *Options) {
o.Values = make([]string, len(other.Values))
copy(o.Values, other.Values)
o.mtime = other.mtime
o.fileinfo = other.fileinfo
}
// OptionIndex locates a specific option and returns its index within
// the receiver's Values. If no option is found -1 is returned.
//
func (o *Options) OptionIndex(s string) int {
for i := 0; i < len(o.Values); i++ {
if o.Values[i] == s {
return i
}
}
return -1
}
// ReadFromFile reads options from a text file.
//
// Options files are word-based with each non-blank, non-comment line
// being split into space-separated fields.
//
// An optional 'filter' function can be supplied which is applied to
// each option word before it is added to the receiver's Values slice.
//
// Returns true if everything worked, false if the file could not be
// read for some reason.
//
func (o *Options) ReadFromFile(filename string, filter func(string) string) (bool, error) {
file, err := os.Open(filename)
if err != nil {
return false, err
}
defer file.Close()
o.Path = filename
info, err := file.Stat()
if err != nil {
return true, err
}
o.fileinfo = info
o.SetModTime(info.ModTime())
return o.ReadFromReader(file, filename, filter)
}
// Read options from the given io.Reader.
//
func (o *Options) ReadFromReader(r io.Reader, filename string, filter func(string) string) (bool, error) {
if filter == nil {
filter = func(s string) string { return s }
}
var conditional Conditional
input := bufio.NewScanner(r)
lineNumber := 0
for input.Scan() {
line := input.Text()
lineNumber++
if line == "" || line[0] == '#' {
continue
}
fields := strings.Fields(line)
if len(fields) == 0 {
continue
}
evalCondition := func(invert bool) error {
if len(fields) != 2 {
return reportErrorInFile(filename, lineNumber, fmt.Sprintf("%s requires a single parameter", fields[0]))
}
val := os.Getenv(fields[1])
state1, state2 := TrueConditionState, FalseConditionState
if invert {
state1, state2 = FalseConditionState, TrueConditionState
}
if val != "" {
conditional.PushState(state1)
} else {
conditional.PushState(state2)
}
return nil
}
if fields[0] == errorDirective {
if !conditional.IsSkippingLines() {
message := strings.Join(fields[1:], " ")
if message == "" {
message = "error"
}
return false, reportErrorInFile(filename, lineNumber, message)
}
continue
}
if fields[0] == ifdefDirective {
if conditional.IsSkippingLines() {
conditional.PushState(conditional.CurrentState())
} else if err := evalCondition(false); err != nil {
return false, err
} else {
continue
}
}
if fields[0] == ifndefDirective {
if conditional.IsSkippingLines() {
conditional.PushState(conditional.CurrentState())
} else if err := evalCondition(true); err != nil {
return false, err
} else {
continue
}
}
if fields[0] == elseDirective {
if !conditional.IsActive() {
return false, reportErrorInFile(filename, lineNumber, ErrNoCondition.Error())
}
conditional.ToggleState()
continue
}
if fields[0] == endifDirective {
if !conditional.IsActive() {
return false, reportErrorInFile(filename, lineNumber, ErrNoCondition.Error())
}
if err := conditional.PopState(); err != nil {
return false, err
}
continue
}
if conditional.IsSkippingLines() {
continue
}
// !include <filename>
//
if fields[0] == includeDirective {
if err := o.includeFile(filename, lineNumber, line, fields, filter); err != nil {
return false, err
}
continue
}
// !inherit [<filename>]
//
if fields[0] == inheritDirective {
if err := o.inheritFile(filename, lineNumber, line, fields, filter); err != nil {
return false, err
}
continue
}
// Otherwise, treat fields (tokens) as options to be included.
// Expand (interpolate) any variable references, filter and
// collect any non-empty strings.
for _, field := range fields {
field = os.ExpandEnv(field)
fields2 := strings.Fields(field)
for _, field2 := range fields2 {
if field2 = filter(field2); field2 != "" {
o.Values = append(o.Values, field2)
}
}
}
}
return true, nil
}
func extractFilename(filename string) string {
if len(filename) < 2 {
return filename
}
if filename[0] == '"' {
return RemoveDelimiters(filename, '"', '"')
}
if filename[0] == '<' {
return RemoveDelimiters(filename, '<', '>')
}
return filename
}
func reportErrorInFile(filename string, lineNumber int, what string) error {
return fmt.Errorf("error: %s:%d %s", filename, lineNumber, what)
}
func malformedLine(filename string, lineNumber int, what, line string) error {
return reportErrorInFile(filename, lineNumber, fmt.Sprintf("malformed %s - %s", what, line))
}
func (o *Options) includeFile(parentFilename string, lineNumber int, line string, fields []string, filter func(string) string) error {
if len(fields) != 2 {
return malformedLine(parentFilename, lineNumber, includeDirective, line)
}
Assert(fields[1] != "", "unexpected empty field returned from strings.Fields()")
filename := fields[1]
if filename[0] == '"' {
filename = RemoveDelimiters(filename, '"', '"')
} else if filename[0] == '<' {
filename = RemoveDelimiters(filename, '<', '>')
}
path := filepath.Join(filepath.Dir(parentFilename), filename)
if Debug {
log.Printf("DEBUG: %q including %q", parentFilename, path)
}
_, err := o.ReadFromFile(path, filter)
return err
}
func (o *Options) inheritFile(parentFilename string, lineNumber int, line string, fields []string, filter func(string) string) error {
if len(fields) > 2 {
return malformedLine(parentFilename, lineNumber, inheritDirective, line)
}
startingDir, inheritedFilename := ParentDir(parentFilename), Basename(parentFilename)
if len(fields) > 1 {
inheritedFilename = fields[1]
}
if Debug {
log.Printf("OPTIONS: %q !inherit (%q)", parentFilename, inheritedFilename)
}
path, _, found, err := FindFileFromDirectory(inheritedFilename, startingDir)
if err != nil {
return err
}
if !found {
return reportErrorInFile(parentFilename, lineNumber, fmt.Sprintf("inherited file %q not found", inheritedFilename))
}
if Debug {
log.Printf("DEBUG: %q inheriting %q", parentFilename, path)
}
ok, err := o.ReadFromFile(path, filter)
if err != nil {
return err
}
if !ok {
return reportErrorInFile(parentFilename, lineNumber, fmt.Sprintf("error reading inherited file %q", path))
}
return nil
}
//
// MostRecentModTime returns the modification time of the most recently
// modified of the two Options.
//
func MostRecentModTime(a *Options, b *Options) time.Time {
at, bt := a.ModTime(), b.ModTime()
if at.After(bt) {
return at
}
return bt
}