libos: Add libos + very basic ArgumentParser

libluna but for stuff that interests only userspace, like an argument parser or files or stuff like that.

CMakeLists.txt

@@ -29,6 +29,7 @@ set(CMAKE_FIND_ROOT_PATH ${LUNA_ROOT}/toolchain/${LUNA_ARCH}-luna)
 message(STATUS "Configuring Luna for ${LUNA_ARCH}")
 
 add_subdirectory(libluna)
+add_subdirectory(libos)
 add_subdirectory(libc)
 add_subdirectory(kernel)
 add_subdirectory(apps)

apps/CMakeLists.txt

@@ -8,7 +8,11 @@ endfunction()
 
 luna_app(init.cpp init)
 luna_app(cat.cpp cat)
-luna_app(edit.cpp edit)
 luna_app(sh.cpp sh)
 luna_app(date.cpp date)
+
+luna_app(edit.cpp edit)
+target_link_libraries(edit PRIVATE os)
+
 luna_app(ls.cpp ls)
+target_link_libraries(ls PRIVATE os)

apps/edit.cpp

@@ -1,3 +1,5 @@
+#include <os/ArgumentParser.h>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -5,17 +7,16 @@
 int main(int argc, char** argv)
 {
     FILE* f;
+    StringView pathname;
 
-    if (argc < 2)
-    {
-        fprintf(stderr, "usage: %s [file]", argv[0]);
-        return 1;
-    }
+    ArgumentParser parser;
+    parser.add_positional_argument(pathname, "file", true);
+    parser.parse(argc, argv);
 
-    f = fopen(argv[1], "w");
+    f = fopen(pathname.chars(), "w");
     if (!f)
     {
-        perror(argv[1]);
+        perror(pathname.chars());
         return 1;
     }
 

apps/ls.cpp

@@ -1,3 +1,5 @@
+#include <os/ArgumentParser.h>
+
 #include <dirent.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -5,12 +7,13 @@
 
 int main(int argc, char** argv)
 {
-    const char* pathname;
-    if (argc == 1) pathname = "/";
-    else
-        pathname = argv[1];
+    StringView pathname;
 
-    DIR* dp = opendir(pathname);
+    ArgumentParser parser;
+    parser.add_positional_argument(pathname, "directory", false, "/");
+    parser.parse(argc, argv);
+
+    DIR* dp = opendir(pathname.chars());
     if (!dp)
     {
         perror("opendir");

libluna/include/luna/Vector.h

@@ -103,6 +103,19 @@ template <typename T> class Vector
         return move(m_data[m_size]);
     }
 
+    Option<T> try_dequeue()
+    {
+        if (m_size == 0) return {};
+
+        T item = move(m_data[0]);
+
+        memmove(m_data, m_data + 1, m_size - 1);
+
+        m_size--;
+
+        return move(item);
+    }
+
     const T& operator[](usize index) const
     {
         check(index < m_size);

libos/CMakeLists.txt

@@ -0,0 +1,27 @@
+# The C++ standard library for OS operations (userspace only), so most things that have to do with calling the kernel, or functions that the kernel has no use for.
+
+file(GLOB HEADERS include/os/*.h)
+
+set(SOURCES
+    ${HEADERS}
+    src/ArgumentParser.cpp
+)
+
+add_library(os ${SOURCES})
+target_compile_options(os PRIVATE -Os -Wall -Wextra -Werror -Wvla)
+target_compile_options(os PRIVATE -Wdisabled-optimization -Wformat=2 -Winit-self)
+target_compile_options(os PRIVATE -Wmissing-include-dirs -Wswitch-default -Wcast-qual -Wundef) 
+target_compile_options(os PRIVATE -Wcast-align -Wwrite-strings -Wlogical-op -Wredundant-decls -Wshadow -Wconversion)
+target_compile_options(os PRIVATE -fno-asynchronous-unwind-tables -fno-omit-frame-pointer -std=c++20 -fno-rtti -fno-exceptions)
+target_include_directories(os PUBLIC include/)
+target_include_directories(os PUBLIC ${LUNA_BASE}/usr/include)
+
+if("${LUNA_ARCH}" MATCHES "x86_64")
+target_compile_definitions(os PUBLIC ARCH_X86_64)
+endif()
+
+if(LUNA_DEBUG_SYMBOLS)
+    message(STATUS "Building libOS with debug symbols")
+    target_compile_options(os PRIVATE -ggdb)
+    target_compile_options(os-freestanding PRIVATE -ggdb)
+endif()

libos/include/os/ArgumentParser.h

@@ -0,0 +1,25 @@
+#pragma once
+#include <luna/StringView.h>
+#include <luna/Vector.h>
+
+class ArgumentParser
+{
+  public:
+    ArgumentParser() = default;
+
+    Result<void> add_positional_argument(StringView& out, StringView name, bool required);
+    Result<void> add_positional_argument(StringView& out, StringView name, bool required, StringView fallback);
+
+    void parse(int argc, char* const* argv);
+
+  private:
+    struct PositionalArgument
+    {
+        StringView* out;
+        StringView name;
+        bool required;
+        StringView fallback;
+    };
+
+    Vector<PositionalArgument> m_positional_args;
+};

libos/src/ArgumentParser.cpp

@@ -0,0 +1,47 @@
+#include <os/ArgumentParser.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+Result<void> ArgumentParser::add_positional_argument(StringView& out, StringView name, bool required)
+{
+    PositionalArgument arg { &out, name, required, {} };
+
+    return m_positional_args.try_append(move(arg));
+}
+
+Result<void> ArgumentParser::add_positional_argument(StringView& out, StringView name, bool required,
+                                                     StringView fallback)
+{
+    PositionalArgument arg { &out, name, required, fallback };
+
+    return m_positional_args.try_append(move(arg));
+}
+
+void ArgumentParser::parse(int argc, char* const* argv)
+{
+    StringView program_name = argv[0];
+
+    for (int i = 1; i < argc; i++)
+    {
+        StringView arg = argv[i];
+        Option<PositionalArgument> current = m_positional_args.try_dequeue();
+        if (!current.has_value())
+        {
+            fprintf(stderr, "%s: unused argument '%s'\n", program_name.chars(), arg.chars());
+            continue;
+        }
+
+        *current->out = arg;
+    }
+
+    // Loop through all remaining positional arguments.
+    for (const auto& arg : m_positional_args)
+    {
+        if (arg.required)
+        {
+            fprintf(stderr, "%s: required argument '%s' not provided\n", program_name.chars(), arg.name.chars());
+            exit(1);
+        }
+        else { *arg.out = arg.fallback; }
+    }
+}

tools/check-formatting.sh

@@ -7,6 +7,8 @@ cd $LUNA_ROOT
 SOURCES=($(find kernel/src -type f | grep -v "\.asm"))
 SOURCES+=($(find libluna/src -type f))
 SOURCES+=($(find libluna/include/luna -type f))
+SOURCES+=($(find libos/src -type f))
+SOURCES+=($(find libos/include/os -type f))
 
 ALL_OK=1
 

tools/check-stdint.sh

@@ -8,6 +8,8 @@ cd $LUNA_ROOT
 SOURCES=($(find kernel/src -type f | grep -v "\.asm" | grep -v "bootboot.h"))
 SOURCES+=($(find libluna/src -type f))
 SOURCES+=($(find libluna/include/luna -type f | grep -v "Types.h"))
+SOURCES+=($(find libos/src -type f))
+SOURCES+=($(find libos/include/os -type f))
 
 SUCCESS=1
 

tools/install-headers.sh

@@ -8,6 +8,8 @@ cd $LUNA_ROOT
 mkdir -p $LUNA_BASE
 mkdir -p $LUNA_BASE/usr/include
 mkdir -p $LUNA_BASE/usr/include/luna
+mkdir -p $LUNA_BASE/usr/include/os
 
 cp --preserve=timestamps -RT libc/include/ $LUNA_BASE/usr/include
 cp --preserve=timestamps -RT libluna/include/luna/ $LUNA_BASE/usr/include/luna
+cp --preserve=timestamps -RT libos/include/os/ $LUNA_BASE/usr/include/os

tools/replace-stdint.sh

@@ -8,6 +8,8 @@ cd $LUNA_ROOT
 SOURCES=($(find kernel/src -type f | grep -v "\.asm" | grep -v "bootboot.h"))
 SOURCES+=($(find libluna/src -type f))
 SOURCES+=($(find libluna/include/luna -type f | grep -v "Types.h"))
+SOURCES+=($(find libos/src -type f))
+SOURCES+=($(find libos/include/os -type f))
 
 for f in ${SOURCES[@]}
 do

tools/run-clang-format.sh

@@ -8,6 +8,8 @@ cd $LUNA_ROOT
 SOURCES=($(find kernel/src -type f | grep -v "\.asm"))
 SOURCES+=($(find libluna/src -type f))
 SOURCES+=($(find libluna/include/luna -type f))
+SOURCES+=($(find libos/src -type f))
+SOURCES+=($(find libos/include/os -type f))
 
 for f in ${SOURCES[@]}
 do