lshal: register options for ListCommand.

ListCommand parseArgs() and usage() uses a list of RegisteredOption's
instead of hardcoding all options.

Test: lshal_test
Change-Id: I94418b22791fbff7a17756c4266252a76570fb84

2 files changed, 227 insertions, 125 deletions

diff --git a/cmds/lshal/ListCommand.cpp b/cmds/lshal/ListCommand.cpp
index c7a41a3ba1..8b59fb867d 100644
--- a/cmds/lshal/ListCommand.cpp
+++ b/cmds/lshal/ListCommand.cpp
@@ -611,29 +611,119 @@ Status ListCommand::fetch() {
     return status;
 }
 
+void ListCommand::registerAllOptions() {
+    int v = mOptions.size();
+    // A list of acceptable command line options
+    // key: value returned by getopt_long
+    // long options with short alternatives
+    mOptions.push_back({'h', "help", no_argument, v++, [](ListCommand*, const char*) {
+        return USAGE;
+    }, ""});
+    mOptions.push_back({'i', "interface", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::INTERFACE_NAME);
+        return OK;
+    }, "print the instance name column"});
+    mOptions.push_back({'t', "transport", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::TRANSPORT);
+        return OK;
+    }, "print the transport mode column"});
+    mOptions.push_back({'r', "arch", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::ARCH);
+        return OK;
+    }, "print the bitness column"});
+    mOptions.push_back({'p', "pid", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::SERVER_PID);
+        return OK;
+    }, "print the server PID, or server cmdline if -m is set"});
+    mOptions.push_back({'a', "address", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::SERVER_ADDR);
+        return OK;
+    }, "print the server object address column"});
+    mOptions.push_back({'c', "clients", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::CLIENT_PIDS);
+        return OK;
+    }, "print the client PIDs, or client cmdlines if -m is set"});
+    mOptions.push_back({'e', "threads", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mSelectedColumns.push_back(TableColumnType::THREADS);
+        return OK;
+    }, "print currently used/available threads\n(note, available threads created lazily)"});
+    mOptions.push_back({'m', "cmdline", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mEnableCmdlines = true;
+        return OK;
+    }, "print cmdline instead of PIDs"});
+    mOptions.push_back({'d', "debug", optional_argument, v++, [](ListCommand* thiz, const char* arg) {
+        thiz->mEmitDebugInfo = true;
+        if (arg) thiz->mFileOutputPath = arg;
+        return OK;
+    }, "Emit debug info from\nIBase::debug with empty options. Cannot be used with --neat.\n"
+        "Writes to specified file if 'arg' is provided, otherwise stdout."});
+
+    // long options without short alternatives
+    mOptions.push_back({'\0', "init-vintf", no_argument, v++, [](ListCommand* thiz, const char* arg) {
+        thiz->mVintf = true;
+        if (arg) thiz->mFileOutputPath = arg;
+        return OK;
+    }, "form a skeleton HAL manifest to specified file,\nor stdout if no file specified."});
+    mOptions.push_back({'\0', "sort", required_argument, v++, [](ListCommand* thiz, const char* arg) {
+        if (strcmp(arg, "interface") == 0 || strcmp(arg, "i") == 0) {
+            thiz->mSortColumn = TableEntry::sortByInterfaceName;
+        } else if (strcmp(arg, "pid") == 0 || strcmp(arg, "p") == 0) {
+            thiz->mSortColumn = TableEntry::sortByServerPid;
+        } else {
+            thiz->err() << "Unrecognized sorting column: " << arg << std::endl;
+            return USAGE;
+        }
+        return OK;
+    }, "sort by a column. 'arg' can be (i|interface) or (p|pid)."});
+    mOptions.push_back({'\0', "neat", no_argument, v++, [](ListCommand* thiz, const char*) {
+        thiz->mNeat = true;
+        return OK;
+    }, "output is machine parsable (no explanatory text).\nCannot be used with --debug."});
+}
+
+// Create 'longopts' argument to getopt_long. Caller is responsible for maintaining
+// the lifetime of "options" during the usage of the returned array.
+static std::unique_ptr<struct option[]> getLongOptions(
+        const ListCommand::RegisteredOptions& options,
+        int* longOptFlag) {
+    std::unique_ptr<struct option[]> ret{new struct option[options.size() + 1]};
+    int i = 0;
+    for (const auto& e : options) {
+        ret[i].name = e.longOption.c_str();
+        ret[i].has_arg = e.hasArg;
+        ret[i].flag = longOptFlag;
+        ret[i].val = e.val;
+
+        i++;
+    }
+    // getopt_long last option has all zeros
+    ret[i].name = NULL;
+    ret[i].has_arg = 0;
+    ret[i].flag = NULL;
+    ret[i].val = 0;
+
+    return ret;
+}
+
+// Create 'optstring' argument to getopt_long.
+static std::string getShortOptions(const ListCommand::RegisteredOptions& options) {
+    std::stringstream ss;
+    for (const auto& e : options) {
+        if (e.shortOption != '\0') {
+            ss << e.shortOption;
+        }
+    }
+    return ss.str();
+}
+
 Status ListCommand::parseArgs(const Arg &arg) {
-    static struct option longOptions[] = {
-        // long options with short alternatives
-        {"help",      no_argument,       0, 'h' },
-        {"interface", no_argument,       0, 'i' },
-        {"transport", no_argument,       0, 't' },
-        {"arch",      no_argument,       0, 'r' },
-        {"pid",       no_argument,       0, 'p' },
-        {"address",   no_argument,       0, 'a' },
-        {"clients",   no_argument,       0, 'c' },
-        {"threads",   no_argument,       0, 'e' },
-        {"cmdline",   no_argument,       0, 'm' },
-        {"debug",     optional_argument, 0, 'd' },
-
-        // long options without short alternatives
-        {"sort",      required_argument, 0, 's' },
-        {"init-vintf",optional_argument, 0, 'v' },
-        {"neat",      no_argument,       0, 'n' },
-        { 0,          0,                 0,  0  }
-    };
-
-    std::vector<TableColumnType> selectedColumns;
-    bool enableCmdlines = false;
+
+    if (mOptions.empty()) {
+        registerAllOptions();
+    }
+    int longOptFlag;
+    std::unique_ptr<struct option[]> longOptions = getLongOptions(mOptions, &longOptFlag);
+    std::string shortOptions = getShortOptions(mOptions);
 
     // suppress output to std::err for unknown options
     opterr = 0;
@@ -642,77 +732,34 @@ Status ListCommand::parseArgs(const Arg &arg) {
     int c;
     // Lshal::parseArgs has set optind to the next option to parse
     for (;;) {
-        // using getopt_long in case we want to add other options in the future
         c = getopt_long(arg.argc, arg.argv,
-                "hitrpacmde", longOptions, &optionIndex);
+                shortOptions.c_str(), longOptions.get(), &optionIndex);
         if (c == -1) {
             break;
         }
-        switch (c) {
-        case 's': {
-            if (strcmp(optarg, "interface") == 0 || strcmp(optarg, "i") == 0) {
-                mSortColumn = TableEntry::sortByInterfaceName;
-            } else if (strcmp(optarg, "pid") == 0 || strcmp(optarg, "p") == 0) {
-                mSortColumn = TableEntry::sortByServerPid;
-            } else {
-                err() << "Unrecognized sorting column: " << optarg << std::endl;
-                return USAGE;
+        const RegisteredOption* found = nullptr;
+        if (c == 0) {
+            // see long option
+            for (const auto& e : mOptions) {
+                if (longOptFlag == e.val) found = &e;
+            }
+        } else {
+            // see short option
+            for (const auto& e : mOptions) {
+                if (c == e.shortOption) found = &e;
             }
-            break;
-        }
-        case 'v': {
-            mVintf = true;
-            if (optarg) mFileOutputPath = optarg;
-            break;
-        }
-        case 'i': {
-            selectedColumns.push_back(TableColumnType::INTERFACE_NAME);
-            break;
-        }
-        case 't': {
-            selectedColumns.push_back(TableColumnType::TRANSPORT);
-            break;
-        }
-        case 'r': {
-            selectedColumns.push_back(TableColumnType::ARCH);
-            break;
-        }
-        case 'p': {
-            selectedColumns.push_back(TableColumnType::SERVER_PID);
-            break;
-        }
-        case 'a': {
-            selectedColumns.push_back(TableColumnType::SERVER_ADDR);
-            break;
-        }
-        case 'c': {
-            selectedColumns.push_back(TableColumnType::CLIENT_PIDS);
-            break;
-        }
-        case 'e': {
-            selectedColumns.push_back(TableColumnType::THREADS);
-            break;
-        }
-        case 'm': {
-            enableCmdlines = true;
-            break;
-        }
-        case 'd': {
-            mEmitDebugInfo = true;
-            if (optarg) mFileOutputPath = optarg;
-            break;
-        }
-        case 'n': {
-            mNeat = true;
-            break;
-        }
-        case 'h': {
-            return USAGE;
         }
-        default: // see unrecognized options
+
+        if (found == nullptr) {
+            // see unrecognized options
             err() << "unrecognized option `" << arg.argv[optind - 1] << "'" << std::endl;
             return USAGE;
         }
+
+        Status status = found->op(this, optarg);
+        if (status != OK) {
+            return status;
+        }
     }
     if (optind < arg.argc) {
         // see non option
@@ -725,24 +772,24 @@ Status ListCommand::parseArgs(const Arg &arg) {
         return USAGE;
     }
 
-    if (selectedColumns.empty()) {
-        selectedColumns = {TableColumnType::INTERFACE_NAME, TableColumnType::THREADS,
+    if (mSelectedColumns.empty()) {
+        mSelectedColumns = {TableColumnType::INTERFACE_NAME, TableColumnType::THREADS,
                             TableColumnType::SERVER_PID, TableColumnType::CLIENT_PIDS};
     }
 
-    if (enableCmdlines) {
-        for (size_t i = 0; i < selectedColumns.size(); ++i) {
-            if (selectedColumns[i] == TableColumnType::SERVER_PID) {
-                selectedColumns[i] = TableColumnType::SERVER_CMD;
+    if (mEnableCmdlines) {
+        for (size_t i = 0; i < mSelectedColumns.size(); ++i) {
+            if (mSelectedColumns[i] == TableColumnType::SERVER_PID) {
+                mSelectedColumns[i] = TableColumnType::SERVER_CMD;
             }
-            if (selectedColumns[i] == TableColumnType::CLIENT_PIDS) {
-                selectedColumns[i] = TableColumnType::CLIENT_CMDS;
+            if (mSelectedColumns[i] == TableColumnType::CLIENT_PIDS) {
+                mSelectedColumns[i] = TableColumnType::CLIENT_CMDS;
             }
         }
     }
 
-    forEachTable([&selectedColumns] (Table& table) {
-        table.setSelectedColumns(selectedColumns);
+    forEachTable([this] (Table& table) {
+        table.setSelectedColumns(this->mSelectedColumns);
     });
 
     return OK;
@@ -759,39 +806,64 @@ Status ListCommand::main(const Arg &arg) {
     return status;
 }
 
+static std::vector<std::string> splitString(const std::string &s, char c) {
+    std::vector<std::string> components;
+
+    size_t startPos = 0;
+    size_t matchPos;
+    while ((matchPos = s.find(c, startPos)) != std::string::npos) {
+        components.push_back(s.substr(startPos, matchPos - startPos));
+        startPos = matchPos + 1;
+    }
+
+    if (startPos <= s.length()) {
+        components.push_back(s.substr(startPos));
+    }
+    return components;
+}
+
+const std::string& ListCommand::RegisteredOption::getHelpMessageForArgument() const {
+    static const std::string empty{};
+    static const std::string optional{"[=<arg>]"};
+    static const std::string required{"=<arg>"};
+
+    if (hasArg == optional_argument) {
+        return optional;
+    }
+    if (hasArg == required_argument) {
+        return required;
+    }
+    return empty;
+}
+
 void ListCommand::usage() const {
 
-    static const std::string list =
-            "list:\n"
-            "    lshal\n"
-            "    lshal list\n"
-            "        List all hals with default ordering and columns (`lshal list -iepc`)\n"
-            "    lshal list [-h|--help]\n"
-            "        -h, --help: Print help message for list (`lshal help list`)\n"
-            "    lshal [list] [--interface|-i] [--transport|-t] [-r|--arch] [-e|--threads]\n"
-            "            [--pid|-p] [--address|-a] [--clients|-c] [--cmdline|-m]\n"
-            "            [--sort={interface|i|pid|p}] [--init-vintf[=<output file>]]\n"
-            "            [--debug|-d[=<output file>]] [--neat]\n"
-            "        -i, --interface: print the interface name column\n"
-            "        -n, --instance: print the instance name column\n"
-            "        -t, --transport: print the transport mode column\n"
-            "        -r, --arch: print if the HAL is in 64-bit or 32-bit\n"
-            "        -e, --threads: print currently used/available threads\n"
-            "                       (note, available threads created lazily)\n"
-            "        -p, --pid: print the server PID, or server cmdline if -m is set\n"
-            "        -a, --address: print the server object address column\n"
-            "        -c, --clients: print the client PIDs, or client cmdlines if -m is set\n"
-            "        -m, --cmdline: print cmdline instead of PIDs\n"
-            "        -d[=<output file>], --debug[=<output file>]: emit debug info from \n"
-            "                IBase::debug with empty options. Cannot be used with --neat.\n"
-            "        --sort=i, --sort=interface: sort by interface name\n"
-            "        --sort=p, --sort=pid: sort by server pid\n"
-            "        --neat: output is machine parsable (no explanatory text)\n"
-            "                Cannot be used with --debug.\n"
-            "        --init-vintf[=<output file>]: form a skeleton HAL manifest to specified\n"
-            "                      file, or stdout if no file specified.\n";
-
-    err() << list;
+    err() << "list:" << std::endl
+          << "    lshal" << std::endl
+          << "    lshal list" << std::endl
+          << "        List all hals with default ordering and columns (`lshal list -iepc`)" << std::endl
+          << "    lshal list [-h|--help]" << std::endl
+          << "        -h, --help: Print help message for list (`lshal help list`)" << std::endl
+          << "    lshal [list] [OPTIONS...]" << std::endl;
+    for (const auto& e : mOptions) {
+        if (e.help.empty()) {
+            continue;
+        }
+        err() << "        ";
+        if (e.shortOption != '\0')
+            err() << "-" << e.shortOption << e.getHelpMessageForArgument();
+        if (e.shortOption != '\0' && !e.longOption.empty())
+            err() << ", ";
+        if (!e.longOption.empty())
+            err() << "--" << e.longOption << e.getHelpMessageForArgument();
+        err() << ": ";
+        std::vector<std::string> lines = splitString(e.help, '\n');
+        for (const auto& line : lines) {
+            if (&line != &lines.front())
+                err() << "            ";
+            err() << line << std::endl;
+        }
+    }
 }
 
 }  // namespace lshal
diff --git a/cmds/lshal/ListCommand.h b/cmds/lshal/ListCommand.h
index 346af28589..5bc834c320 100644
--- a/cmds/lshal/ListCommand.h
+++ b/cmds/lshal/ListCommand.h
@@ -17,6 +17,7 @@
 #ifndef FRAMEWORK_NATIVE_CMDS_LSHAL_LIST_COMMAND_H_
 #define FRAMEWORK_NATIVE_CMDS_LSHAL_LIST_COMMAND_H_
 
+#include <getopt.h>
 #include <stdint.h>
 
 #include <fstream>
@@ -53,6 +54,27 @@ public:
     std::string getName() const override { return GetName(); }
 
     static std::string GetName();
+
+    struct RegisteredOption {
+        // short alternative, e.g. 'v'. If '\0', no short options is available.
+        char shortOption;
+        // long alternative, e.g. 'init-vintf'
+        std::string longOption;
+        // no_argument, required_argument or optional_argument
+        int hasArg;
+        // value written to 'flag' by getopt_long
+        int val;
+        // operation when the argument is present
+        std::function<Status(ListCommand* thiz, const char* arg)> op;
+        // help message
+        std::string help;
+
+        const std::string& getHelpMessageForArgument() const;
+    };
+    // A list of acceptable command line options
+    // key: value returned by getopt_long
+    using RegisteredOptions = std::vector<RegisteredOption>;
+
 protected:
     Status parseArgs(const Arg &arg);
     Status fetch();
@@ -85,6 +107,8 @@ protected:
     NullableOStream<std::ostream> err() const;
     NullableOStream<std::ostream> out() const;
 
+    void registerAllOptions();
+
     Table mServicesTable{};
     Table mPassthroughRefTable{};
     Table mImplementationsTable{};
@@ -105,6 +129,12 @@ protected:
     // If an entry exist and not empty, it contains the cached content of /proc/{pid}/cmdline.
     std::map<pid_t, std::string> mCmdlines;
 
+    RegisteredOptions mOptions;
+    // All selected columns
+    std::vector<TableColumnType> mSelectedColumns;
+    // If true, emit cmdlines instead of PIDs
+    bool mEnableCmdlines = false;
+
 private:
     DISALLOW_COPY_AND_ASSIGN(ListCommand);
 };