1 files changed, 109 insertions, 0 deletions
diff --git a/tools/aapt2/Flag.cpp b/tools/aapt2/Flag.cpp
new file mode 100644
index 000000000000..b1ee8e7bcd4c
--- /dev/null
+++ b/tools/aapt2/Flag.cpp
@@ -0,0 +1,109 @@
+#include "Flag.h"
+#include "StringPiece.h"
+
+#include <functional>
+#include <iomanip>
+#include <iostream>
+#include <string>
+#include <vector>
+
+namespace aapt {
+namespace flag {
+
+struct Flag {
+    std::string name;
+    std::string description;
+    std::function<void(const StringPiece&)> action;
+    bool required;
+    bool* flagResult;
+    bool parsed;
+};
+
+static std::vector<Flag> sFlags;
+static std::vector<std::string> sArgs;
+
+void optionalFlag(const StringPiece& name, const StringPiece& description,
+                  std::function<void(const StringPiece&)> action) {
+    sFlags.push_back(
+            Flag{ name.toString(), description.toString(), action, false, nullptr, false });
+}
+
+void requiredFlag(const StringPiece& name, const StringPiece& description,
+                  std::function<void(const StringPiece&)> action) {
+    sFlags.push_back(
+            Flag{ name.toString(), description.toString(), action, true, nullptr, false });
+}
+
+void optionalSwitch(const StringPiece& name, const StringPiece& description, bool* result) {
+    sFlags.push_back(
+            Flag{ name.toString(), description.toString(), {}, false, result, false });
+}
+
+static void usageAndDie(const StringPiece& command) {
+    std::cerr << command << " [options]";
+    for (const Flag& flag : sFlags) {
+        if (flag.required) {
+            std::cerr << " " << flag.name << " arg";
+        }
+    }
+    std::cerr << " files..." << std::endl << std::endl << "Options:" << std::endl;
+
+    for (const Flag& flag : sFlags) {
+        std::string command = flag.name;
+        if (!flag.flagResult) {
+            command += " arg ";
+        }
+        std::cerr << "  " << std::setw(30) << std::left << command
+                  << flag.description << std::endl;
+    }
+    exit(1);
+}
+
+void parse(int argc, char** argv, const StringPiece& command) {
+    for (int i = 0; i < argc; i++) {
+        const StringPiece arg(argv[i]);
+        if (*arg.data() != '-') {
+            sArgs.emplace_back(arg.toString());
+            continue;
+        }
+
+        bool match = false;
+        for (Flag& flag : sFlags) {
+            if (arg == flag.name) {
+                match = true;
+                flag.parsed = true;
+                if (flag.flagResult) {
+                    *flag.flagResult = true;
+                } else {
+                    i++;
+                    if (i >= argc) {
+                        std::cerr << flag.name << " missing argument." << std::endl
+                                  << std::endl;
+                        usageAndDie(command);
+                    }
+                    flag.action(argv[i]);
+                }
+                break;
+            }
+        }
+
+        if (!match) {
+            std::cerr << "unknown option '" << arg << "'." << std::endl << std::endl;
+            usageAndDie(command);
+        }
+    }
+
+    for (const Flag& flag : sFlags) {
+        if (flag.required && !flag.parsed) {
+            std::cerr << "missing required flag " << flag.name << std::endl << std::endl;
+            usageAndDie(command);
+        }
+    }
+}
+
+const std::vector<std::string>& getArgs() {
+    return sArgs;
+}
+
+} // namespace flag
+} // namespace aapt