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+// Copyright (c) 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---
+
+// Bash-style command line flag completion for C++ binaries
+//
+// This module implements bash-style completions. It achieves this
+// goal in the following broad chunks:
+//
+// 1) Take a to-be-completed word, and examine it for search hints
+// 2) Identify all potentially matching flags
+// 2a) If there are no matching flags, do nothing.
+// 2b) If all matching flags share a common prefix longer than the
+// completion word, output just that matching prefix
+// 3) Categorize those flags to produce a rough ordering of relevence.
+// 4) Potentially trim the set of flags returned to a smaller number
+// that bash is happier with
+// 5) Output the matching flags in groups ordered by relevence.
+// 5a) Force bash to place most-relevent groups at the top of the list
+// 5b) Trim most flag's descriptions to fit on a single terminal line
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h> // for strlen
+
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "config.h"
+#include "util.h"
+
+#include "gflags/gflags.h"
+#include "gflags/gflags_completions.h"
+
+using std::set;
+using std::string;
+using std::vector;
+
+
+DEFINE_string(tab_completion_word, "",
+ "If non-empty, HandleCommandLineCompletions() will hijack the "
+ "process and attempt to do bash-style command line flag "
+ "completion on this value.");
+DEFINE_int32(tab_completion_columns, 80,
+ "Number of columns to use in output for tab completion");
+
+
+namespace GFLAGS_NAMESPACE {
+
+
+namespace {
+// Function prototypes and Type forward declarations. Code may be
+// more easily understood if it is roughly ordered according to
+// control flow, rather than by C's "declare before use" ordering
+struct CompletionOptions;
+struct NotableFlags;
+
+// The entry point if flag completion is to be used.
+static void PrintFlagCompletionInfo(void);
+
+
+// 1) Examine search word
+static void CanonicalizeCursorWordAndSearchOptions(
+ const string &cursor_word,
+ string *canonical_search_token,
+ CompletionOptions *options);
+
+static bool RemoveTrailingChar(string *str, char c);
+
+
+// 2) Find all matches
+static void FindMatchingFlags(
+ const vector<CommandLineFlagInfo> &all_flags,
+ const CompletionOptions &options,
+ const string &match_token,
+ set<const CommandLineFlagInfo *> *all_matches,
+ string *longest_common_prefix);
+
+static bool DoesSingleFlagMatch(
+ const CommandLineFlagInfo &flag,
+ const CompletionOptions &options,
+ const string &match_token);
+
+
+// 3) Categorize matches
+static void CategorizeAllMatchingFlags(
+ const set<const CommandLineFlagInfo *> &all_matches,
+ const string &search_token,
+ const string &module,
+ const string &package_dir,
+ NotableFlags *notable_flags);
+
+static void TryFindModuleAndPackageDir(
+ const vector<CommandLineFlagInfo> &all_flags,
+ string *module,
+ string *package_dir);
+
+
+// 4) Decide which flags to use
+static void FinalizeCompletionOutput(
+ const set<const CommandLineFlagInfo *> &matching_flags,
+ CompletionOptions *options,
+ NotableFlags *notable_flags,
+ vector<string> *completions);
+
+static void RetrieveUnusedFlags(
+ const set<const CommandLineFlagInfo *> &matching_flags,
+ const NotableFlags &notable_flags,
+ set<const CommandLineFlagInfo *> *unused_flags);
+
+
+// 5) Output matches
+static void OutputSingleGroupWithLimit(
+ const set<const CommandLineFlagInfo *> &group,
+ const string &line_indentation,
+ const string &header,
+ const string &footer,
+ bool long_output_format,
+ int *remaining_line_limit,
+ size_t *completion_elements_added,
+ vector<string> *completions);
+
+// (helpers for #5)
+static string GetShortFlagLine(
+ const string &line_indentation,
+ const CommandLineFlagInfo &info);
+
+static string GetLongFlagLine(
+ const string &line_indentation,
+ const CommandLineFlagInfo &info);
+
+
+//
+// Useful types
+
+// Try to deduce the intentions behind this completion attempt. Return the
+// canonical search term in 'canonical_search_token'. Binary search options
+// are returned in the various booleans, which should all have intuitive
+// semantics, possibly except:
+// - return_all_matching_flags: Generally, we'll trim the number of
+// returned candidates to some small number, showing those that are
+// most likely to be useful first. If this is set, however, the user
+// really does want us to return every single flag as an option.
+// - force_no_update: Any time we output lines, all of which share a
+// common prefix, bash will 'helpfully' not even bother to show the
+// output, instead changing the current word to be that common prefix.
+// If it's clear this shouldn't happen, we'll set this boolean
+struct CompletionOptions {
+ bool flag_name_substring_search;
+ bool flag_location_substring_search;
+ bool flag_description_substring_search;
+ bool return_all_matching_flags;
+ bool force_no_update;
+};
+
+// Notable flags are flags that are special or preferred for some
+// reason. For example, flags that are defined in the binary's module
+// are expected to be much more relevent than flags defined in some
+// other random location. These sets are specified roughly in precedence
+// order. Once a flag is placed in one of these 'higher' sets, it won't
+// be placed in any of the 'lower' sets.
+struct NotableFlags {
+ typedef set<const CommandLineFlagInfo *> FlagSet;
+ FlagSet perfect_match_flag;
+ FlagSet module_flags; // Found in module file
+ FlagSet package_flags; // Found in same directory as module file
+ FlagSet most_common_flags; // One of the XXX most commonly supplied flags
+ FlagSet subpackage_flags; // Found in subdirectories of package
+};
+
+
+//
+// Tab completion implementation - entry point
+static void PrintFlagCompletionInfo(void) {
+ string cursor_word = FLAGS_tab_completion_word;
+ string canonical_token;
+ CompletionOptions options = { };
+ CanonicalizeCursorWordAndSearchOptions(
+ cursor_word,
+ &canonical_token,
+ &options);
+
+ DVLOG(1) << "Identified canonical_token: '" << canonical_token << "'";
+
+ vector<CommandLineFlagInfo> all_flags;
+ set<const CommandLineFlagInfo *> matching_flags;
+ GetAllFlags(&all_flags);
+ DVLOG(2) << "Found " << all_flags.size() << " flags overall";
+
+ string longest_common_prefix;
+ FindMatchingFlags(
+ all_flags,
+ options,
+ canonical_token,
+ &matching_flags,
+ &longest_common_prefix);
+ DVLOG(1) << "Identified " << matching_flags.size() << " matching flags";
+ DVLOG(1) << "Identified " << longest_common_prefix
+ << " as longest common prefix.";
+ if (longest_common_prefix.size() > canonical_token.size()) {
+ // There's actually a shared common prefix to all matching flags,
+ // so may as well output that and quit quickly.
+ DVLOG(1) << "The common prefix '" << longest_common_prefix
+ << "' was longer than the token '" << canonical_token
+ << "'. Returning just this prefix for completion.";
+ fprintf(stdout, "--%s", longest_common_prefix.c_str());
+ return;
+ }
+ if (matching_flags.empty()) {
+ VLOG(1) << "There were no matching flags, returning nothing.";
+ return;
+ }
+
+ string module;
+ string package_dir;
+ TryFindModuleAndPackageDir(all_flags, &module, &package_dir);
+ DVLOG(1) << "Identified module: '" << module << "'";
+ DVLOG(1) << "Identified package_dir: '" << package_dir << "'";
+
+ NotableFlags notable_flags;
+ CategorizeAllMatchingFlags(
+ matching_flags,
+ canonical_token,
+ module,
+ package_dir,
+ &notable_flags);
+ DVLOG(2) << "Categorized matching flags:";
+ DVLOG(2) << " perfect_match: " << notable_flags.perfect_match_flag.size();
+ DVLOG(2) << " module: " << notable_flags.module_flags.size();
+ DVLOG(2) << " package: " << notable_flags.package_flags.size();
+ DVLOG(2) << " most common: " << notable_flags.most_common_flags.size();
+ DVLOG(2) << " subpackage: " << notable_flags.subpackage_flags.size();
+
+ vector<string> completions;
+ FinalizeCompletionOutput(
+ matching_flags,
+ &options,
+ &notable_flags,
+ &completions);
+
+ if (options.force_no_update)
+ completions.push_back("~");
+
+ DVLOG(1) << "Finalized with " << completions.size()
+ << " chosen completions";
+
+ for (vector<string>::const_iterator it = completions.begin();
+ it != completions.end();
+ ++it) {
+ DVLOG(9) << " Completion entry: '" << *it << "'";
+ fprintf(stdout, "%s\n", it->c_str());
+ }
+}
+
+
+// 1) Examine search word (and helper method)
+static void CanonicalizeCursorWordAndSearchOptions(
+ const string &cursor_word,
+ string *canonical_search_token,
+ CompletionOptions *options) {
+ *canonical_search_token = cursor_word;
+ if (canonical_search_token->empty()) return;
+
+ // Get rid of leading quotes and dashes in the search term
+ if ((*canonical_search_token)[0] == '"')
+ *canonical_search_token = canonical_search_token->substr(1);
+ while ((*canonical_search_token)[0] == '-')
+ *canonical_search_token = canonical_search_token->substr(1);
+
+ options->flag_name_substring_search = false;
+ options->flag_location_substring_search = false;
+ options->flag_description_substring_search = false;
+ options->return_all_matching_flags = false;
+ options->force_no_update = false;
+
+ // Look for all search options we can deduce now. Do this by walking
+ // backwards through the term, looking for up to three '?' and up to
+ // one '+' as suffixed characters. Consume them if found, and remove
+ // them from the canonical search token.
+ int found_question_marks = 0;
+ int found_plusses = 0;
+ while (true) {
+ if (found_question_marks < 3 &&
+ RemoveTrailingChar(canonical_search_token, '?')) {
+ ++found_question_marks;
+ continue;
+ }
+ if (found_plusses < 1 &&
+ RemoveTrailingChar(canonical_search_token, '+')) {
+ ++found_plusses;
+ continue;
+ }
+ break;
+ }
+
+ switch (found_question_marks) { // all fallthroughs
+ case 3: options->flag_description_substring_search = true;
+ case 2: options->flag_location_substring_search = true;
+ case 1: options->flag_name_substring_search = true;
+ };
+
+ options->return_all_matching_flags = (found_plusses > 0);
+}
+
+// Returns true if a char was removed
+static bool RemoveTrailingChar(string *str, char c) {
+ if (str->empty()) return false;
+ if ((*str)[str->size() - 1] == c) {
+ *str = str->substr(0, str->size() - 1);
+ return true;
+ }
+ return false;
+}
+
+
+// 2) Find all matches (and helper methods)
+static void FindMatchingFlags(
+ const vector<CommandLineFlagInfo> &all_flags,
+ const CompletionOptions &options,
+ const string &match_token,
+ set<const CommandLineFlagInfo *> *all_matches,
+ string *longest_common_prefix) {
+ all_matches->clear();
+ bool first_match = true;
+ for (vector<CommandLineFlagInfo>::const_iterator it = all_flags.begin();
+ it != all_flags.end();
+ ++it) {
+ if (DoesSingleFlagMatch(*it, options, match_token)) {
+ all_matches->insert(&*it);
+ if (first_match) {
+ first_match = false;
+ *longest_common_prefix = it->name;
+ } else {
+ if (longest_common_prefix->empty() || it->name.empty()) {
+ longest_common_prefix->clear();
+ continue;
+ }
+ string::size_type pos = 0;
+ while (pos < longest_common_prefix->size() &&
+ pos < it->name.size() &&
+ (*longest_common_prefix)[pos] == it->name[pos])
+ ++pos;
+ longest_common_prefix->erase(pos);
+ }
+ }
+ }
+}
+
+// Given the set of all flags, the parsed match options, and the
+// canonical search token, produce the set of all candidate matching
+// flags for subsequent analysis or filtering.
+static bool DoesSingleFlagMatch(
+ const CommandLineFlagInfo &flag,
+ const CompletionOptions &options,
+ const string &match_token) {
+ // Is there a prefix match?
+ string::size_type pos = flag.name.find(match_token);
+ if (pos == 0) return true;
+
+ // Is there a substring match if we want it?
+ if (options.flag_name_substring_search &&
+ pos != string::npos)
+ return true;
+
+ // Is there a location match if we want it?
+ if (options.flag_location_substring_search &&
+ flag.filename.find(match_token) != string::npos)
+ return true;
+
+ // TODO(user): All searches should probably be case-insensitive
+ // (especially this one...)
+ if (options.flag_description_substring_search &&
+ flag.description.find(match_token) != string::npos)
+ return true;
+
+ return false;
+}
+
+// 3) Categorize matches (and helper method)
+
+// Given a set of matching flags, categorize them by
+// likely relevence to this specific binary
+static void CategorizeAllMatchingFlags(
+ const set<const CommandLineFlagInfo *> &all_matches,
+ const string &search_token,
+ const string &module, // empty if we couldn't find any
+ const string &package_dir, // empty if we couldn't find any
+ NotableFlags *notable_flags) {
+ notable_flags->perfect_match_flag.clear();
+ notable_flags->module_flags.clear();
+ notable_flags->package_flags.clear();
+ notable_flags->most_common_flags.clear();
+ notable_flags->subpackage_flags.clear();
+
+ for (set<const CommandLineFlagInfo *>::const_iterator it =
+ all_matches.begin();
+ it != all_matches.end();
+ ++it) {
+ DVLOG(2) << "Examining match '" << (*it)->name << "'";
+ DVLOG(7) << " filename: '" << (*it)->filename << "'";
+ string::size_type pos = string::npos;
+ if (!package_dir.empty())
+ pos = (*it)->filename.find(package_dir);
+ string::size_type slash = string::npos;
+ if (pos != string::npos) // candidate for package or subpackage match
+ slash = (*it)->filename.find(
+ PATH_SEPARATOR,
+ pos + package_dir.size() + 1);
+
+ if ((*it)->name == search_token) {
+ // Exact match on some flag's name
+ notable_flags->perfect_match_flag.insert(*it);
+ DVLOG(3) << "Result: perfect match";
+ } else if (!module.empty() && (*it)->filename == module) {
+ // Exact match on module filename
+ notable_flags->module_flags.insert(*it);
+ DVLOG(3) << "Result: module match";
+ } else if (!package_dir.empty() &&
+ pos != string::npos && slash == string::npos) {
+ // In the package, since there was no slash after the package portion
+ notable_flags->package_flags.insert(*it);
+ DVLOG(3) << "Result: package match";
+ } else if (false) {
+ // In the list of the XXX most commonly supplied flags overall
+ // TODO(user): Compile this list.
+ DVLOG(3) << "Result: most-common match";
+ } else if (!package_dir.empty() &&
+ pos != string::npos && slash != string::npos) {
+ // In a subdirectory of the package
+ notable_flags->subpackage_flags.insert(*it);
+ DVLOG(3) << "Result: subpackage match";
+ }
+
+ DVLOG(3) << "Result: not special match";
+ }
+}
+
+static void PushNameWithSuffix(vector<string>* suffixes, const char* suffix) {
+ suffixes->push_back(
+ StringPrintf("/%s%s", ProgramInvocationShortName(), suffix));
+}
+
+static void TryFindModuleAndPackageDir(
+ const vector<CommandLineFlagInfo> &all_flags,
+ string *module,
+ string *package_dir) {
+ module->clear();
+ package_dir->clear();
+
+ vector<string> suffixes;
+ // TODO(user): There's some inherant ambiguity here - multiple directories
+ // could share the same trailing folder and file structure (and even worse,
+ // same file names), causing us to be unsure as to which of the two is the
+ // actual package for this binary. In this case, we'll arbitrarily choose.
+ PushNameWithSuffix(&suffixes, ".");
+ PushNameWithSuffix(&suffixes, "-main.");
+ PushNameWithSuffix(&suffixes, "_main.");
+ // These four are new but probably merited?
+ PushNameWithSuffix(&suffixes, "-test.");
+ PushNameWithSuffix(&suffixes, "_test.");
+ PushNameWithSuffix(&suffixes, "-unittest.");
+ PushNameWithSuffix(&suffixes, "_unittest.");
+
+ for (vector<CommandLineFlagInfo>::const_iterator it = all_flags.begin();
+ it != all_flags.end();
+ ++it) {
+ for (vector<string>::const_iterator suffix = suffixes.begin();
+ suffix != suffixes.end();
+ ++suffix) {
+ // TODO(user): Make sure the match is near the end of the string
+ if (it->filename.find(*suffix) != string::npos) {
+ *module = it->filename;
+ string::size_type sep = it->filename.rfind(PATH_SEPARATOR);
+ *package_dir = it->filename.substr(0, (sep == string::npos) ? 0 : sep);
+ return;
+ }
+ }
+ }
+}
+
+// Can't specialize template type on a locally defined type. Silly C++...
+struct DisplayInfoGroup {
+ const char* header;
+ const char* footer;
+ set<const CommandLineFlagInfo *> *group;
+
+ int SizeInLines() const {
+ int size_in_lines = static_cast<int>(group->size()) + 1;
+ if (strlen(header) > 0) {
+ size_in_lines++;
+ }
+ if (strlen(footer) > 0) {
+ size_in_lines++;
+ }
+ return size_in_lines;
+ }
+};
+
+// 4) Finalize and trim output flag set
+static void FinalizeCompletionOutput(
+ const set<const CommandLineFlagInfo *> &matching_flags,
+ CompletionOptions *options,
+ NotableFlags *notable_flags,
+ vector<string> *completions) {
+
+ // We want to output lines in groups. Each group needs to be indented
+ // the same to keep its lines together. Unless otherwise required,
+ // only 99 lines should be output to prevent bash from harassing the
+ // user.
+
+ // First, figure out which output groups we'll actually use. For each
+ // nonempty group, there will be ~3 lines of header & footer, plus all
+ // output lines themselves.
+ int max_desired_lines = // "999999 flags should be enough for anyone. -dave"
+ (options->return_all_matching_flags ? 999999 : 98);
+ int lines_so_far = 0;
+
+ vector<DisplayInfoGroup> output_groups;
+ bool perfect_match_found = false;
+ if (lines_so_far < max_desired_lines &&
+ !notable_flags->perfect_match_flag.empty()) {
+ perfect_match_found = true;
+ DisplayInfoGroup group =
+ { "",
+ "==========",
+ &notable_flags->perfect_match_flag };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+ if (lines_so_far < max_desired_lines &&
+ !notable_flags->module_flags.empty()) {
+ DisplayInfoGroup group = {
+ "-* Matching module flags *-",
+ "===========================",
+ &notable_flags->module_flags };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+ if (lines_so_far < max_desired_lines &&
+ !notable_flags->package_flags.empty()) {
+ DisplayInfoGroup group = {
+ "-* Matching package flags *-",
+ "============================",
+ &notable_flags->package_flags };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+ if (lines_so_far < max_desired_lines &&
+ !notable_flags->most_common_flags.empty()) {
+ DisplayInfoGroup group = {
+ "-* Commonly used flags *-",
+ "=========================",
+ &notable_flags->most_common_flags };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+ if (lines_so_far < max_desired_lines &&
+ !notable_flags->subpackage_flags.empty()) {
+ DisplayInfoGroup group = {
+ "-* Matching sub-package flags *-",
+ "================================",
+ &notable_flags->subpackage_flags };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+
+ set<const CommandLineFlagInfo *> obscure_flags; // flags not notable
+ if (lines_so_far < max_desired_lines) {
+ RetrieveUnusedFlags(matching_flags, *notable_flags, &obscure_flags);
+ if (!obscure_flags.empty()) {
+ DisplayInfoGroup group = {
+ "-* Other flags *-",
+ "",
+ &obscure_flags };
+ lines_so_far += group.SizeInLines();
+ output_groups.push_back(group);
+ }
+ }
+
+ // Second, go through each of the chosen output groups and output
+ // as many of those flags as we can, while remaining below our limit
+ int remaining_lines = max_desired_lines;
+ size_t completions_output = 0;
+ int indent = static_cast<int>(output_groups.size()) - 1;
+ for (vector<DisplayInfoGroup>::const_iterator it =
+ output_groups.begin();
+ it != output_groups.end();
+ ++it, --indent) {
+ OutputSingleGroupWithLimit(
+ *it->group, // group
+ string(indent, ' '), // line indentation
+ string(it->header), // header
+ string(it->footer), // footer
+ perfect_match_found, // long format
+ &remaining_lines, // line limit - reduces this by number printed
+ &completions_output, // completions (not lines) added
+ completions); // produced completions
+ perfect_match_found = false;
+ }
+
+ if (completions_output != matching_flags.size()) {
+ options->force_no_update = false;
+ completions->push_back("~ (Remaining flags hidden) ~");
+ } else {
+ options->force_no_update = true;
+ }
+}
+
+static void RetrieveUnusedFlags(
+ const set<const CommandLineFlagInfo *> &matching_flags,
+ const NotableFlags &notable_flags,
+ set<const CommandLineFlagInfo *> *unused_flags) {
+ // Remove from 'matching_flags' set all members of the sets of
+ // flags we've already printed (specifically, those in notable_flags)
+ for (set<const CommandLineFlagInfo *>::const_iterator it =
+ matching_flags.begin();
+ it != matching_flags.end();
+ ++it) {
+ if (notable_flags.perfect_match_flag.count(*it) ||
+ notable_flags.module_flags.count(*it) ||
+ notable_flags.package_flags.count(*it) ||
+ notable_flags.most_common_flags.count(*it) ||
+ notable_flags.subpackage_flags.count(*it))
+ continue;
+ unused_flags->insert(*it);
+ }
+}
+
+// 5) Output matches (and helper methods)
+
+static void OutputSingleGroupWithLimit(
+ const set<const CommandLineFlagInfo *> &group,
+ const string &line_indentation,
+ const string &header,
+ const string &footer,
+ bool long_output_format,
+ int *remaining_line_limit,
+ size_t *completion_elements_output,
+ vector<string> *completions) {
+ if (group.empty()) return;
+ if (!header.empty()) {
+ if (*remaining_line_limit < 2) return;
+ *remaining_line_limit -= 2;
+ completions->push_back(line_indentation + header);
+ completions->push_back(line_indentation + string(header.size(), '-'));
+ }
+ for (set<const CommandLineFlagInfo *>::const_iterator it = group.begin();
+ it != group.end() && *remaining_line_limit > 0;
+ ++it) {
+ --*remaining_line_limit;
+ ++*completion_elements_output;
+ completions->push_back(
+ (long_output_format
+ ? GetLongFlagLine(line_indentation, **it)
+ : GetShortFlagLine(line_indentation, **it)));
+ }
+ if (!footer.empty()) {
+ if (*remaining_line_limit < 1) return;
+ --*remaining_line_limit;
+ completions->push_back(line_indentation + footer);
+ }
+}
+
+static string GetShortFlagLine(
+ const string &line_indentation,
+ const CommandLineFlagInfo &info) {
+ string prefix;
+ bool is_string = (info.type == "string");
+ SStringPrintf(&prefix, "%s--%s [%s%s%s] ",
+ line_indentation.c_str(),
+ info.name.c_str(),
+ (is_string ? "'" : ""),
+ info.default_value.c_str(),
+ (is_string ? "'" : ""));
+ int remainder =
+ FLAGS_tab_completion_columns - static_cast<int>(prefix.size());
+ string suffix;
+ if (remainder > 0)
+ suffix =
+ (static_cast<int>(info.description.size()) > remainder ?
+ (info.description.substr(0, remainder - 3) + "...").c_str() :
+ info.description.c_str());
+ return prefix + suffix;
+}
+
+static string GetLongFlagLine(
+ const string &line_indentation,
+ const CommandLineFlagInfo &info) {
+
+ string output = DescribeOneFlag(info);
+
+ // Replace '-' with '--', and remove trailing newline before appending
+ // the module definition location.
+ string old_flagname = "-" + info.name;
+ output.replace(
+ output.find(old_flagname),
+ old_flagname.size(),
+ "-" + old_flagname);
+ // Stick a newline and indentation in front of the type and default
+ // portions of DescribeOneFlag()s description
+ static const char kNewlineWithIndent[] = "\n ";
+ output.replace(output.find(" type:"), 1, string(kNewlineWithIndent));
+ output.replace(output.find(" default:"), 1, string(kNewlineWithIndent));
+ output = StringPrintf("%s Details for '--%s':\n"
+ "%s defined: %s",
+ line_indentation.c_str(),
+ info.name.c_str(),
+ output.c_str(),
+ info.filename.c_str());
+
+ // Eliminate any doubled newlines that crept in. Specifically, if
+ // DescribeOneFlag() decided to break the line just before "type"
+ // or "default", we don't want to introduce an extra blank line
+ static const string line_of_spaces(FLAGS_tab_completion_columns, ' ');
+ static const char kDoubledNewlines[] = "\n \n";
+ for (string::size_type newlines = output.find(kDoubledNewlines);
+ newlines != string::npos;
+ newlines = output.find(kDoubledNewlines))
+ // Replace each 'doubled newline' with a single newline
+ output.replace(newlines, sizeof(kDoubledNewlines) - 1, string("\n"));
+
+ for (string::size_type newline = output.find('\n');
+ newline != string::npos;
+ newline = output.find('\n')) {
+ int newline_pos = static_cast<int>(newline) % FLAGS_tab_completion_columns;
+ int missing_spaces = FLAGS_tab_completion_columns - newline_pos;
+ output.replace(newline, 1, line_of_spaces, 1, missing_spaces);
+ }
+ return output;
+}
+} // anonymous
+
+void HandleCommandLineCompletions(void) {
+ if (FLAGS_tab_completion_word.empty()) return;
+ PrintFlagCompletionInfo();
+ gflags_exitfunc(0);
+}
+
+
+} // namespace GFLAGS_NAMESPACE