Add support for Windows #![no_main] (#62)

johnthagen · web-flow · commit e493017f67a0 · 2024-03-17T14:51:10.000-04:00
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -11,7 +11,7 @@ jobs:
         toolchain: [ stable, nightly ]
     runs-on: ${{ matrix.platform }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.toolchain }}
@@ -25,21 +25,35 @@ jobs:
         toolchain: [ stable, nightly ]
     runs-on: ${{ matrix.platform }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.toolchain }}
       - name: Build
         working-directory: no_std
         run: cargo build --release --all-features
+  no_main_win:
+    name: no_main-win
+    strategy:
+      matrix:
+        toolchain: [ stable, nightly ]
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.toolchain }}
+      - name: Build
+        working-directory: no_main/win
+        run: cargo build --release --all-features
   build_std:
     name: build-std
     strategy:
       matrix:
-        project_dir: [ build_std, no_main ]
+        project_dir: [ build_std, no_main/nix ]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: nightly
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,7 +1,6 @@
 [package]
 name = "min-sized-rust"
 version = "0.1.0"
-authors = ["johnthagen <johnthagen@gmail.com>"]
 edition = "2021"
 license-file = "LICENSE.txt"
 
diff --git a/README.md b/README.md
@@ -233,7 +233,7 @@ On macOS, the final stripped binary size is reduced to 30KB.
 
 ![Minimum Rust: Nightly](https://img.shields.io/badge/Minimum%20Rust%20Version-nightly-orange.svg)
 
-> Example project is located in the [`no_main`](no_main) folder.
+> Example projects are located in the [`no_main`](no_main) folder.
 
 Up until this point, we haven't restricted what utilities we used from `libstd`. In this section
 we will restrict our usage of `libstd` in order to reduce binary size further.
diff --git a/no_main/nix/.gitignore b/no_main/nix/.gitignore
diff --git a/no_main/nix/Cargo.lock b/no_main/nix/Cargo.lock
diff --git a/no_main/nix/Cargo.toml b/no_main/nix/Cargo.toml
@@ -1,7 +1,6 @@
 [package]
 name = "no_main"
 version = "0.1.0"
-authors = ["johnthagen <johnthagen@gmail.com>", "Vitaly '_Vi' Shukela <vi0oss@gmail.com>"]
 edition = "2021"
 license = "MIT"
 
diff --git a/no_main/nix/src/main.rs b/no_main/nix/src/main.rs
diff --git a/no_main/win/.gitignore b/no_main/win/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/no_main/win/Cargo.lock b/no_main/win/Cargo.lock
diff --git a/no_main/win/Cargo.toml b/no_main/win/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "no_main"
+version = "0.1.0"
+edition = "2021"
+license = "MIT"
+
+[dependencies]
+
+[profile.release]
+opt-level = "z"
+lto = true
+codegen-units = 1
+panic = "abort"
+strip = true
diff --git a/no_main/win/src/main.rs b/no_main/win/src/main.rs
@@ -0,0 +1,24 @@
+#![no_main]
+
+use std::fs::File;
+use std::io::Write as _;
+use std::os::windows::{io::FromRawHandle as _, raw::HANDLE};
+
+#[link(name = "kernel32")]
+extern "system" {
+    pub fn GetStdHandle(nstdhandle: u32) -> HANDLE;
+}
+
+pub const STD_OUTPUT_HANDLE: u32 = 4294967285;
+
+fn stdout() -> File {
+    unsafe { File::from_raw_handle(GetStdHandle(STD_OUTPUT_HANDLE)) }
+}
+
+#[no_mangle]
+pub fn main(_argc: i32, _argv: *const *const u8) -> u32 {
+    let mut stdout = stdout();
+    stdout.write_all(b"Hello, world!\n").unwrap();
+
+    0
+}
diff --git a/no_std/Cargo.toml b/no_std/Cargo.toml
@@ -1,7 +1,6 @@
 [package]
 name = "min-sized-no_std"
 version = "0.1.0"
-authors = ["johnthagen <johnthagen@gmail.com>"]
 edition = "2021"
 license = "MIT"
 
