init: remove Parser singleton and related cleanup

* Remove the Parser singleton (Hooray!)
* Rename parser.* to tokenizer.* as this is actually a tokenizer
* Rename init_parser.* to parser.* as this is a generic parser
* Move contents of init_parser_test.cpp to service_test.cpp as this
  actually is a test of the parsing in MakeExecOneshotService() and
  nothing related to (init_)parser.cpp

Test: boot bullhead
Test: bool sailfish
Test: init unit tests
Change-Id: I4fe39e6483f58ebd3ce5ee715a45dbba0acf5d91
diff --git a/init/parser.cpp b/init/parser.cpp
index c0fa6d9..c6f4f45 100644
--- a/init/parser.cpp
+++ b/init/parser.cpp
@@ -1,123 +1,156 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 #include "parser.h"
 
+#include <dirent.h>
+
+#include <android-base/chrono_utils.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
+#include "tokenizer.h"
+#include "util.h"
+
 namespace android {
 namespace init {
 
-int next_token(struct parse_state *state)
-{
-    char *x = state->ptr;
-    char *s;
+Parser::Parser() {}
 
-    if (state->nexttoken) {
-        int t = state->nexttoken;
-        state->nexttoken = 0;
-        return t;
-    }
+void Parser::AddSectionParser(const std::string& name, std::unique_ptr<SectionParser> parser) {
+    section_parsers_[name] = std::move(parser);
+}
+
+void Parser::AddSingleLineParser(const std::string& prefix, LineCallback callback) {
+    line_callbacks_.emplace_back(prefix, callback);
+}
+
+void Parser::ParseData(const std::string& filename, const std::string& data) {
+    // TODO: Use a parser with const input and remove this copy
+    std::vector<char> data_copy(data.begin(), data.end());
+    data_copy.push_back('\0');
+
+    parse_state state;
+    state.line = 0;
+    state.ptr = &data_copy[0];
+    state.nexttoken = 0;
+
+    SectionParser* section_parser = nullptr;
+    std::vector<std::string> args;
 
     for (;;) {
-        switch (*x) {
-        case 0:
-            state->ptr = x;
-            return T_EOF;
-        case '\n':
-            x++;
-            state->ptr = x;
-            return T_NEWLINE;
-        case ' ':
-        case '\t':
-        case '\r':
-            x++;
-            continue;
-        case '#':
-            while (*x && (*x != '\n')) x++;
-            if (*x == '\n') {
-                state->ptr = x+1;
-                return T_NEWLINE;
-            } else {
-                state->ptr = x;
-                return T_EOF;
-            }
-        default:
-            goto text;
+        switch (next_token(&state)) {
+            case T_EOF:
+                if (section_parser) section_parser->EndSection();
+                return;
+            case T_NEWLINE:
+                state.line++;
+                if (args.empty()) break;
+                // If we have a line matching a prefix we recognize, call its callback and unset any
+                // current section parsers.  This is meant for /sys/ and /dev/ line entries for
+                // uevent.
+                for (const auto& [prefix, callback] : line_callbacks_) {
+                    if (android::base::StartsWith(args[0], prefix.c_str())) {
+                        if (section_parser) section_parser->EndSection();
+
+                        std::string ret_err;
+                        if (!callback(std::move(args), &ret_err)) {
+                            LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
+                        }
+                        section_parser = nullptr;
+                        break;
+                    }
+                }
+                if (section_parsers_.count(args[0])) {
+                    if (section_parser) section_parser->EndSection();
+                    section_parser = section_parsers_[args[0]].get();
+                    std::string ret_err;
+                    if (!section_parser->ParseSection(std::move(args), filename, state.line,
+                                                      &ret_err)) {
+                        LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
+                        section_parser = nullptr;
+                    }
+                } else if (section_parser) {
+                    std::string ret_err;
+                    if (!section_parser->ParseLineSection(std::move(args), state.line, &ret_err)) {
+                        LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
+                    }
+                }
+                args.clear();
+                break;
+            case T_TEXT:
+                args.emplace_back(state.text);
+                break;
         }
     }
+}
+
+bool Parser::ParseConfigFile(const std::string& path) {
+    LOG(INFO) << "Parsing file " << path << "...";
+    android::base::Timer t;
+    std::string data;
+    std::string err;
+    if (!ReadFile(path, &data, &err)) {
+        LOG(ERROR) << err;
+        return false;
+    }
 
-textdone:
-    state->ptr = x;
-    *s = 0;
-    return T_TEXT;
-text:
-    state->text = s = x;
-textresume:
-    for (;;) {
-        switch (*x) {
-        case 0:
-            goto textdone;
-        case ' ':
-        case '\t':
-        case '\r':
-            x++;
-            goto textdone;
-        case '\n':
-            state->nexttoken = T_NEWLINE;
-            x++;
-            goto textdone;
-        case '"':
-            x++;
-            for (;;) {
-                switch (*x) {
-                case 0:
-                        /* unterminated quoted thing */
-                    state->ptr = x;
-                    return T_EOF;
-                case '"':
-                    x++;
-                    goto textresume;
-                default:
-                    *s++ = *x++;
-                }
-            }
-            break;
-        case '\\':
-            x++;
-            switch (*x) {
-            case 0:
-                goto textdone;
-            case 'n':
-                *s++ = '\n';
-                break;
-            case 'r':
-                *s++ = '\r';
-                break;
-            case 't':
-                *s++ = '\t';
-                break;
-            case '\\':
-                *s++ = '\\';
-                break;
-            case '\r':
-                    /* \ <cr> <lf> -> line continuation */
-                if (x[1] != '\n') {
-                    x++;
-                    continue;
-                }
-            case '\n':
-                    /* \ <lf> -> line continuation */
-                state->line++;
-                x++;
-                    /* eat any extra whitespace */
-                while((*x == ' ') || (*x == '\t')) x++;
-                continue;
-            default:
-                    /* unknown escape -- just copy */
-                *s++ = *x++;
-            }
-            continue;
-        default:
-            *s++ = *x++;
+    data.push_back('\n');  // TODO: fix parse_config.
+    ParseData(path, data);
+    for (const auto& [section_name, section_parser] : section_parsers_) {
+        section_parser->EndFile();
+    }
+
+    LOG(VERBOSE) << "(Parsing " << path << " took " << t << ".)";
+    return true;
+}
+
+bool Parser::ParseConfigDir(const std::string& path) {
+    LOG(INFO) << "Parsing directory " << path << "...";
+    std::unique_ptr<DIR, decltype(&closedir)> config_dir(opendir(path.c_str()), closedir);
+    if (!config_dir) {
+        PLOG(ERROR) << "Could not import directory '" << path << "'";
+        return false;
+    }
+    dirent* current_file;
+    std::vector<std::string> files;
+    while ((current_file = readdir(config_dir.get()))) {
+        // Ignore directories and only process regular files.
+        if (current_file->d_type == DT_REG) {
+            std::string current_path =
+                android::base::StringPrintf("%s/%s", path.c_str(), current_file->d_name);
+            files.emplace_back(current_path);
         }
     }
-    return T_EOF;
+    // Sort first so we load files in a consistent order (bug 31996208)
+    std::sort(files.begin(), files.end());
+    for (const auto& file : files) {
+        if (!ParseConfigFile(file)) {
+            LOG(ERROR) << "could not import file '" << file << "'";
+        }
+    }
+    return true;
+}
+
+bool Parser::ParseConfig(const std::string& path) {
+    if (is_dir(path.c_str())) {
+        return ParseConfigDir(path);
+    }
+    return ParseConfigFile(path);
 }
 
 }  // namespace init