From 5f20bd02e07d7ea497bbce6cd562d7bec8c4959e Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Tue, 11 Feb 2014 18:22:51 +0100
Subject: [PATCH] Improve error reporting between kernel<->user

---
 kernel/src/scheduler.cpp  |  7 ++++---
 programs/tsh/src/main.cpp | 11 ++---------
 tstl/include/errors.hpp   | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 12 deletions(-)
 create mode 100644 tstl/include/errors.hpp

diff --git a/kernel/src/scheduler.cpp b/kernel/src/scheduler.cpp
index 74169697..8375c26a 100644
--- a/kernel/src/scheduler.cpp
+++ b/kernel/src/scheduler.cpp
@@ -10,6 +10,7 @@
 #include <optional.hpp>
 #include <string.hpp>
 #include <lock_guard.hpp>
+#include <errors.hpp>
 
 #include "scheduler.hpp"
 #include "paging.hpp"
@@ -532,7 +533,7 @@ int64_t scheduler::exec(const std::string& file){
             k_print_line("Not a file");
         }
 
-        return -1;
+        return -std::ERROR_NOT_EXISTS;
     }
 
     if(!elf::is_valid(content)){
@@ -540,7 +541,7 @@ int64_t scheduler::exec(const std::string& file){
             k_print_line("Not a valid file");
         }
 
-        return -2;
+        return -std::ERROR_NOT_EXECUTABLE;
     }
 
     auto buffer = content.c_str();
@@ -552,7 +553,7 @@ int64_t scheduler::exec(const std::string& file){
             k_print_line("Impossible to create paging");
         }
 
-        return -3;
+        return -std::ERROR_FAILED_EXECUTION;
     }
 
     process.brk_start = program_break;
diff --git a/programs/tsh/src/main.cpp b/programs/tsh/src/main.cpp
index 29c2b29c..f0ec9bdd 100644
--- a/programs/tsh/src/main.cpp
+++ b/programs/tsh/src/main.cpp
@@ -9,6 +9,7 @@
 #include <system.hpp>
 #include <string.hpp>
 #include <algorithms.hpp>
+#include <errors.hpp>
 
 namespace {
 
@@ -99,15 +100,7 @@ int main(){
 
                     if(!result.valid()){
                         print("error: ");
-
-                        auto err = result.error();
-                        if(err == 1){
-                            print_line("The file does not exist");
-                        } else if(err == 2){
-                            print_line("The file is not an executable");
-                        } else if(err == 3){
-                            print_line("Failed to execute the file");
-                        }
+                        print_line(std::error_message(result.error()));
                     }
                 }
             }
diff --git a/tstl/include/errors.hpp b/tstl/include/errors.hpp
new file mode 100644
index 00000000..b6279a1c
--- /dev/null
+++ b/tstl/include/errors.hpp
@@ -0,0 +1,32 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef ERRORS_H
+#define ERRORS_H
+
+namespace std {
+
+constexpr const size_t ERROR_NOT_EXISTS = 1;
+constexpr const size_t ERROR_NOT_EXECUTABLE = 2;
+constexpr const size_t ERROR_FAILED_EXECUTION = 3;
+
+inline const char* error_message(size_t error){
+    switch(error){
+        case ERROR_NOT_EXISTS:
+            return "The file does not exist";
+        case ERROR_NOT_EXECUTABLE:
+            return "The file is not an executable";
+        case ERROR_FAILED_EXECUTION:
+            return "Execution failed";
+        default:
+            return "Unknonwn error";
+    }
+}
+
+}
+
+#endif