Fixes executable linker

build-dist.ps1

@@ -1,4 +1,34 @@
-.\dist\bin\nitro.exe build --pkg dist\share\nitro\nitro.npk std
+$root = "$PSScriptRoot\dist\share\nitro"
+
+# linux stubs
+New-Item -ItemType Directory -Path "$root\stub\linux-gnu-x86_64" -Force
+
+.\lib\llvm\bin\llvm-ifs.exe `
+    --output-elf="$root\stub\linux-gnu-x86_64\libc.so" `
+    --arch=x86_64 --bitwidth=64 --endianness=little `
+    "$PSScriptRoot\stub\linux-gnu\libc.ifs"
+
+if ($LASTEXITCODE -ne 0) {
+    exit 1
+}
+
+# darwin stubs
+New-Item -ItemType Directory -Path "$root\stub\darwin" -Force
+Copy-Item "$PSScriptRoot\stub\darwin\libSystem.tbd" -Destination "$root\stub\darwin"
+
+# win32 stubs
+New-Item -ItemType Directory -Path "$root\stub\win32-x86_64" -Force
+./lib/llvm/bin/llvm-lib.exe `
+    /def:"$PSScriptRoot\stub\win32\msvcrt.def" `
+    /machine:x64 `
+    /out:"$root\stub\win32-x86_64\msvcrt.lib"
+
+if ($LASTEXITCODE -ne 0) {
+    exit 1
+}
+
+# std
+.\dist\bin\nitro.exe build --pkg dist\share\nitro\nitro.npk
 
 if ($LASTEXITCODE -ne 0) {
     exit 1

build-dist.sh

@@ -1,2 +1,24 @@
 #!/bin/sh -e
-./dist/bin/nitro build --pkg dist/share/nitro/nitro.npk std
+dir="dist/share/nitro"
+
+# linux stubs
+mkdir -p "$dir/stub/linux-gnu-x86_64"
+
+./lib/llvm/bin/llvm-ifs \
+  --output-elf="$dir/stub/linux-gnu-x86_64/libc.so" \
+  --arch=x86_64 --bitwidth=64 --endianness=little \
+  stub/linux-gnu/libc.ifs
+
+# darwin stubs
+mkdir -p "$dir/stub/darwin"
+cp stub/darwin/libSystem.tbd "$dir/stub/darwin"
+
+# win32 stubs
+mkdir -p "$dir/stub/win32-x86_64"
+./lib/llvm/bin/llvm-lib \
+  /def:stub/win32/msvcrt.def \
+  /machine:x64 \
+  /out:"$dir/stub/win32-x86_64/msvcrt.lib"
+
+# std
+./dist/bin/nitro build --pkg "$dir/nitro.npk"

stage0/src/codegen/mod.rs

@@ -167,7 +167,7 @@ impl<'a> Codegen<'a> {
         };
 
         // Create a function.
-        let name = CStr::from_bytes_with_nul(b"_main\0").unwrap();
+        let name = CStr::from_bytes_with_nul(b"main\0").unwrap();
         let ret = LlvmType::Void(LlvmVoid::new(self));
         let mut func = LlvmFunc::new(self, name, &[], ret);
 

stage0/src/main.rs

@@ -6,7 +6,7 @@ use clap::{command, value_parser, Arg, ArgMatches, Command};
 use std::borrow::Cow;
 use std::error::Error;
 use std::fmt::Write;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::ExitCode;
 
 mod ast;
@@ -48,14 +48,51 @@ fn main() -> ExitCode {
         )
         .get_matches();
 
+    // Get path to stubs.
+    let exe = match std::env::current_exe() {
+        Ok(v) => v,
+        Err(e) => {
+            eprintln!("Cannot get path of the executable: {}.", join_nested(&e));
+            return ExitCode::FAILURE;
+        }
+    };
+
+    let meta = match exe.symlink_metadata() {
+        Ok(v) => v,
+        Err(e) => {
+            eprintln!(
+                "Cannot get metadata of {}: {}.",
+                exe.display(),
+                join_nested(&e)
+            );
+            return ExitCode::FAILURE;
+        }
+    };
+
+    let exe = if !meta.is_symlink() {
+        exe
+    } else {
+        match exe.read_link() {
+            Ok(v) => v,
+            Err(e) => {
+                eprintln!(
+                    "Cannot read the target of {}: {}.",
+                    exe.display(),
+                    join_nested(&e)
+                );
+                return ExitCode::FAILURE;
+            }
+        }
+    };
+
     // Execute the command.
     match args.subcommand().unwrap() {
-        ("build", args) => build(args),
+        ("build", args) => build(args, &exe),
         _ => todo!(),
     }
 }
 
-fn build(args: &ArgMatches) -> ExitCode {
+fn build(args: &ArgMatches, exe: &Path) -> ExitCode {
     // Initialize LLVM.
     unsafe { llvm_init() };
 
@@ -68,11 +105,17 @@ fn build(args: &ArgMatches) -> ExitCode {
     // Setup target resolver.
     let targets = TargetResolver::new();
 
+    // Get path to stubs.
+    let mut stubs = exe.parent().unwrap().parent().unwrap().join("share");
+
+    stubs.push("nitro");
+    stubs.push("stub");
+
     // Setup dependency resolver.
     let deps = DependencyResolver::new();
 
     // Open the project.
-    let mut project = match Project::open(path.as_ref(), &targets, &deps) {
+    let mut project = match Project::open(path.as_ref(), &targets, &stubs, &deps) {
         Ok(v) => v,
         Err(e) => {
             eprintln!("Cannot open {}: {}.", path.display(), join_nested(&e));

stage0/src/pkg/target.rs

@@ -115,6 +115,10 @@ impl PrimitiveTarget {
     pub fn os(&self) -> TargetOs {
         self.os
     }
+
+    pub fn env(&self) -> Option<TargetEnv> {
+        self.env
+    }
 }
 
 impl Display for PrimitiveTarget {