From 35c5bcc89ce713aca02852dc10247a648187ea28 Mon Sep 17 00:00:00 2001
From: Tom Cherry <tomcherry@google.com>
Date: Mon, 24 Apr 2017 16:55:30 -0700
Subject: [PATCH] init: add Parser::AddSingleLineParser()

Add the ability to override the current section being parsed and
instead parse a line by itself if a given line starts with a specific
prefix.

Test: Boot bullhead
Change-Id: Idbbf2682b78996b41d05f3db655c8937a8c6ccda
---
 init/init_parser.cpp | 19 +++++++++++++++++++
 init/init_parser.h   | 27 +++++++++++++++------------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/init/init_parser.cpp b/init/init_parser.cpp
index 5c7af79ee..c8ef8d9e6 100644
--- a/init/init_parser.cpp
+++ b/init/init_parser.cpp
@@ -20,6 +20,7 @@
 
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
+#include <android-base/strings.h>
 
 #include "parser.h"
 #include "util.h"
@@ -37,6 +38,10 @@ void Parser::AddSectionParser(const std::string& name,
     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());
@@ -63,6 +68,20 @@ void Parser::ParseData(const std::string& filename, const std::string& data) {
             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)) {
+                        parse_error(&state, "%s\n", ret_err.c_str());
+                    }
+                    section_parser = nullptr;
+                    break;
+                }
+            }
             if (section_parsers_.count(args[0])) {
                 if (section_parser) {
                     section_parser->EndSection();
diff --git a/init/init_parser.h b/init/init_parser.h
index fe70d7d50..bd8a17805 100644
--- a/init/init_parser.h
+++ b/init/init_parser.h
@@ -57,24 +57,26 @@ class SectionParser {
 
 class Parser {
   public:
+    //  LineCallback is the type for callbacks that can parse a line starting with a given prefix.
+    //
+    //  They take the form of bool Callback(std::vector<std::string>&& args, std::string* err)
+    //
+    //  Similar to ParseSection() and ParseLineSection(), this function returns bool with false
+    //  indicating a failure and has an std::string* err parameter into which an error string can
+    //  be written.
+    using LineCallback = std::function<bool(std::vector<std::string>&&, std::string*)>;
+
     static Parser& GetInstance();
 
     // Exposed for testing
     Parser();
 
     bool ParseConfig(const std::string& path);
-    void AddSectionParser(const std::string& name,
-                          std::unique_ptr<SectionParser> parser);
-
-    void set_is_system_etc_init_loaded(bool loaded) {
-        is_system_etc_init_loaded_ = loaded;
-    }
-    void set_is_vendor_etc_init_loaded(bool loaded) {
-        is_vendor_etc_init_loaded_ = loaded;
-    }
-    void set_is_odm_etc_init_loaded(bool loaded) {
-        is_odm_etc_init_loaded_ = loaded;
-    }
+    void AddSectionParser(const std::string& name, std::unique_ptr<SectionParser> parser);
+    void AddSingleLineParser(const std::string& prefix, LineCallback callback);
+    void set_is_system_etc_init_loaded(bool loaded) { is_system_etc_init_loaded_ = loaded; }
+    void set_is_vendor_etc_init_loaded(bool loaded) { is_vendor_etc_init_loaded_ = loaded; }
+    void set_is_odm_etc_init_loaded(bool loaded) { is_odm_etc_init_loaded_ = loaded; }
     bool is_system_etc_init_loaded() { return is_system_etc_init_loaded_; }
     bool is_vendor_etc_init_loaded() { return is_vendor_etc_init_loaded_; }
     bool is_odm_etc_init_loaded() { return is_odm_etc_init_loaded_; }
@@ -85,6 +87,7 @@ class Parser {
     bool ParseConfigDir(const std::string& path);
 
     std::map<std::string, std::unique_ptr<SectionParser>> section_parsers_;
+    std::vector<std::pair<std::string, LineCallback>> line_callbacks_;
     bool is_system_etc_init_loaded_ = false;
     bool is_vendor_etc_init_loaded_ = false;
     bool is_odm_etc_init_loaded_ = false;