SkCommandLineFlags.cpp revision e13ca329fca4c28cf4e078561f591ab27b743d23 
1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkCommandLineFlags.h"
9#include "SkTDArray.h"
10#include "SkTSort.h"
11
12#include <stdlib.h>
13
14#if defined(GOOGLE3) && (defined(SK_BUILD_FOR_ANDROID) || defined(SK_BUILD_FOR_IOS))
15    // I don't know why, but this is defined by //base only for non-Linux.
16    DECLARE_bool(undefok)
17#else
18    DEFINE_bool(undefok, false, "Silently ignore unknown flags instead of crashing.");
19#endif
20
21template <typename T> static void ignore_result(const T&) {}
22
23bool SkFlagInfo::CreateStringFlag(const char* name, const char* shortName,
24                                  SkCommandLineFlags::StringArray* pStrings,
25                                  const char* defaultValue, const char* helpString,
26                                  const char* extendedHelpString) {
27    SkFlagInfo* info = new SkFlagInfo(name, shortName, kString_FlagType, helpString,
28                                      extendedHelpString);
29    info->fDefaultString.set(defaultValue);
30
31    info->fStrings = pStrings;
32    SetDefaultStrings(pStrings, defaultValue);
33    return true;
34}
35
36void SkFlagInfo::SetDefaultStrings(SkCommandLineFlags::StringArray* pStrings,
37                                   const char* defaultValue) {
38    pStrings->reset();
39    if (nullptr == defaultValue) {
40        return;
41    }
42    // If default is "", leave the array empty.
43    size_t defaultLength = strlen(defaultValue);
44    if (defaultLength > 0) {
45        const char* const defaultEnd = defaultValue + defaultLength;
46        const char* begin = defaultValue;
47        while (true) {
48            while (begin < defaultEnd && ' ' == *begin) {
49                begin++;
50            }
51            if (begin < defaultEnd) {
52                const char* end = begin + 1;
53                while (end < defaultEnd && ' ' != *end) {
54                    end++;
55                }
56                size_t length = end - begin;
57                pStrings->append(begin, length);
58                begin = end + 1;
59            } else {
60                break;
61            }
62        }
63    }
64}
65
66static bool string_is_in(const char* target, const char* set[], size_t len) {
67    for (size_t i = 0; i < len; i++) {
68        if (0 == strcmp(target, set[i])) {
69            return true;
70        }
71    }
72    return false;
73}
74
75/**
76 *  Check to see whether string represents a boolean value.
77 *  @param string C style string to parse.
78 *  @param result Pointer to a boolean which will be set to the value in the string, if the
79 *      string represents a boolean.
80 *  @param boolean True if the string represents a boolean, false otherwise.
81 */
82static bool parse_bool_arg(const char* string, bool* result) {
83    static const char* trueValues[] = { "1", "TRUE", "true" };
84    if (string_is_in(string, trueValues, SK_ARRAY_COUNT(trueValues))) {
85        *result = true;
86        return true;
87    }
88    static const char* falseValues[] = { "0", "FALSE", "false" };
89    if (string_is_in(string, falseValues, SK_ARRAY_COUNT(falseValues))) {
90        *result = false;
91        return true;
92    }
93    SkDebugf("Parameter \"%s\" not supported.\n", string);
94    return false;
95}
96
97bool SkFlagInfo::match(const char* string) {
98    if (SkStrStartsWith(string, '-') && strlen(string) > 1) {
99        string++;
100        const SkString* compareName;
101        if (SkStrStartsWith(string, '-') && strlen(string) > 1) {
102            string++;
103            // There were two dashes. Compare against full name.
104            compareName = &fName;
105        } else {
106            // One dash. Compare against the short name.
107            compareName = &fShortName;
108        }
109        if (kBool_FlagType == fFlagType) {
110            // In this case, go ahead and set the value.
111            if (compareName->equals(string)) {
112                *fBoolValue = true;
113                return true;
114            }
115            if (SkStrStartsWith(string, "no") && strlen(string) > 2) {
116                string += 2;
117                // Only allow "no" to be prepended to the full name.
118                if (fName.equals(string)) {
119                    *fBoolValue = false;
120                    return true;
121                }
122                return false;
123            }
124            int equalIndex = SkStrFind(string, "=");
125            if (equalIndex > 0) {
126                // The string has an equal sign. Check to see if the string matches.
127                SkString flag(string, equalIndex);
128                if (flag.equals(*compareName)) {
129                    // Check to see if the remainder beyond the equal sign is true or false:
130                    string += equalIndex + 1;
131                    parse_bool_arg(string, fBoolValue);
132                    return true;
133                } else {
134                    return false;
135                }
136            }
137        }
138        return compareName->equals(string);
139    } else {
140        // Has no dash
141        return false;
142    }
143    return false;
144}
145
146SkFlagInfo* SkCommandLineFlags::gHead;
147SkString SkCommandLineFlags::gUsage;
148
149void SkCommandLineFlags::SetUsage(const char* usage) {
150    gUsage.set(usage);
151}
152
153// Maximum line length for the help message.
154#define LINE_LENGTH 72
155
156static void print_indented(const SkString& text) {
157    size_t length = text.size();
158    const char* currLine = text.c_str();
159    const char* stop = currLine + length;
160    while (currLine < stop) {
161        int lineBreak = SkStrFind(currLine, "\n");
162        if (lineBreak < 0) {
163            lineBreak = static_cast<int>(strlen(currLine));
164        }
165        if (lineBreak > LINE_LENGTH) {
166            // No line break within line length. Will need to insert one.
167            // Find a space before the line break.
168            int spaceIndex = LINE_LENGTH - 1;
169            while (spaceIndex > 0 && currLine[spaceIndex] != ' ') {
170                spaceIndex--;
171            }
172            int gap;
173            if (0 == spaceIndex) {
174                // No spaces on the entire line. Go ahead and break mid word.
175                spaceIndex = LINE_LENGTH;
176                gap = 0;
177            } else {
178                // Skip the space on the next line
179                gap = 1;
180            }
181            SkDebugf("        %.*s\n", spaceIndex, currLine);
182            currLine += spaceIndex + gap;
183        } else {
184            // the line break is within the limit. Break there.
185            lineBreak++;
186            SkDebugf("        %.*s", lineBreak, currLine);
187            currLine += lineBreak;
188        }
189    }
190}
191
192static void print_help_for_flag(const SkFlagInfo* flag) {
193    SkDebugf("    --%s", flag->name().c_str());
194    const SkString& shortName = flag->shortName();
195    if (shortName.size() > 0) {
196        SkDebugf(" or -%s", shortName.c_str());
197    }
198    SkDebugf(":\ttype: %s", flag->typeAsString().c_str());
199    if (flag->defaultValue().size() > 0) {
200        SkDebugf("\tdefault: %s", flag->defaultValue().c_str());
201    }
202    SkDebugf("\n");
203    const SkString& help = flag->help();
204    print_indented(help);
205    SkDebugf("\n");
206}
207static void print_extended_help_for_flag(const SkFlagInfo* flag) {
208    print_help_for_flag(flag);
209    print_indented(flag->extendedHelp());
210    SkDebugf("\n");
211}
212
213namespace {
214struct CompareFlagsByName {
215    bool operator()(SkFlagInfo* a, SkFlagInfo* b) const {
216        return strcmp(a->name().c_str(), b->name().c_str()) < 0;
217    }
218};
219}  // namespace
220
221void SkCommandLineFlags::Parse(int argc, char** argv) {
222    // Only allow calling this function once.
223    static bool gOnce;
224    if (gOnce) {
225        SkDebugf("Parse should only be called once at the beginning of main!\n");
226        SkASSERT(false);
227        return;
228    }
229    gOnce = true;
230
231    bool helpPrinted = false;
232    // Loop over argv, starting with 1, since the first is just the name of the program.
233    for (int i = 1; i < argc; i++) {
234        if (0 == strcmp("-h", argv[i]) || 0 == strcmp("--help", argv[i])) {
235            // Print help message.
236            SkTDArray<const char*> helpFlags;
237            for (int j = i + 1; j < argc; j++) {
238                if (SkStrStartsWith(argv[j], '-')) {
239                    break;
240                }
241                helpFlags.append(1, &argv[j]);
242            }
243            if (0 == helpFlags.count()) {
244                // Only print general help message if help for specific flags is not requested.
245                SkDebugf("%s\n%s\n", argv[0], gUsage.c_str());
246            }
247            SkDebugf("Flags:\n");
248
249            if (0 == helpFlags.count()) {
250                // If no flags followed --help, print them all
251                SkTDArray<SkFlagInfo*> allFlags;
252                for (SkFlagInfo* flag = SkCommandLineFlags::gHead; flag;
253                     flag = flag->next()) {
254                    allFlags.push(flag);
255                }
256                SkTQSort(&allFlags[0], &allFlags[allFlags.count() - 1],
257                         CompareFlagsByName());
258                for (int i = 0; i < allFlags.count(); ++i) {
259                    print_help_for_flag(allFlags[i]);
260                    if (allFlags[i]->extendedHelp().size() > 0) {
261                        SkDebugf("        Use '--help %s' for more information.\n",
262                                 allFlags[i]->name().c_str());
263                    }
264                }
265            } else {
266                for (SkFlagInfo* flag = SkCommandLineFlags::gHead; flag;
267                     flag = flag->next()) {
268                    for (int k = 0; k < helpFlags.count(); k++) {
269                        if (flag->name().equals(helpFlags[k]) ||
270                            flag->shortName().equals(helpFlags[k])) {
271                            print_extended_help_for_flag(flag);
272                            helpFlags.remove(k);
273                            break;
274                        }
275                    }
276                }
277            }
278            if (helpFlags.count() > 0) {
279                SkDebugf("Requested help for unrecognized flags:\n");
280                for (int k = 0; k < helpFlags.count(); k++) {
281                    SkDebugf("    --%s\n", helpFlags[k]);
282                }
283            }
284            helpPrinted = true;
285        }
286        if (!helpPrinted) {
287            bool flagMatched = false;
288            SkFlagInfo* flag = gHead;
289            while (flag != nullptr) {
290                if (flag->match(argv[i])) {
291                    flagMatched = true;
292                    switch (flag->getFlagType()) {
293                        case SkFlagInfo::kBool_FlagType:
294                            // Can be handled by match, above, but can also be set by the next
295                            // string.
296                            if (i+1 < argc && !SkStrStartsWith(argv[i+1], '-')) {
297                                i++;
298                                bool value;
299                                if (parse_bool_arg(argv[i], &value)) {
300                                    flag->setBool(value);
301                                }
302                            }
303                            break;
304                        case SkFlagInfo::kString_FlagType:
305                            flag->resetStrings();
306                            // Add all arguments until another flag is reached.
307                            while (i+1 < argc) {
308                                char* end = nullptr;
309                                // Negative numbers aren't flags.
310                                ignore_result(strtod(argv[i+1], &end));
311                                if (end == argv[i+1] && SkStrStartsWith(argv[i+1], '-')) {
312                                    break;
313                                }
314                                i++;
315                                flag->append(argv[i]);
316                            }
317                            break;
318                        case SkFlagInfo::kInt_FlagType:
319                            i++;
320                            flag->setInt(atoi(argv[i]));
321                            break;
322                        case SkFlagInfo::kDouble_FlagType:
323                            i++;
324                            flag->setDouble(atof(argv[i]));
325                            break;
326                        default:
327                            SkDEBUGFAIL("Invalid flag type");
328                    }
329                    break;
330                }
331                flag = flag->next();
332            }
333            if (!flagMatched) {
334#if SK_BUILD_FOR_MAC
335                if (SkStrStartsWith(argv[i], "NSDocumentRevisions")
336                        || SkStrStartsWith(argv[i], "-NSDocumentRevisions")) {
337                    i++;  // skip YES
338                } else
339#endif
340                if (FLAGS_undefok) {
341                    SkDebugf("FYI: ignoring unknown flag '%s'.\n", argv[i]);
342                } else {
343                    SkDebugf("Got unknown flag '%s'. Exiting.\n", argv[i]);
344                    exit(-1);
345                }
346            }
347        }
348    }
349    // Since all of the flags have been set, release the memory used by each
350    // flag. FLAGS_x can still be used after this.
351    SkFlagInfo* flag = gHead;
352    gHead = nullptr;
353    while (flag != nullptr) {
354        SkFlagInfo* next = flag->next();
355        delete flag;
356        flag = next;
357    }
358    if (helpPrinted) {
359        exit(0);
360    }
361}
362
363namespace {
364
365template <typename Strings>
366bool ShouldSkipImpl(const Strings& strings, const char* name) {
367    int count = strings.count();
368    size_t testLen = strlen(name);
369    bool anyExclude = count == 0;
370    for (int i = 0; i < strings.count(); ++i) {
371        const char* matchName = strings[i];
372        size_t matchLen = strlen(matchName);
373        bool matchExclude, matchStart, matchEnd;
374        if ((matchExclude = matchName[0] == '~')) {
375            anyExclude = true;
376            matchName++;
377            matchLen--;
378        }
379        if ((matchStart = matchName[0] == '^')) {
380            matchName++;
381            matchLen--;
382        }
383        if ((matchEnd = matchName[matchLen - 1] == '$')) {
384            matchLen--;
385        }
386        if (matchStart ? (!matchEnd || matchLen == testLen)
387                && strncmp(name, matchName, matchLen) == 0
388                : matchEnd ? matchLen <= testLen
389                && strncmp(name + testLen - matchLen, matchName, matchLen) == 0
390                : strstr(name, matchName) != 0) {
391            return matchExclude;
392        }
393    }
394    return !anyExclude;
395}
396
397}  // namespace
398
399bool SkCommandLineFlags::ShouldSkip(const SkTDArray<const char*>& strings, const char* name) {
400    return ShouldSkipImpl(strings, name);
401}
402bool SkCommandLineFlags::ShouldSkip(const StringArray& strings, const char* name) {
403    return ShouldSkipImpl(strings, name);
404}
405