From 4752c65f416bf3ec2edcccb63ea758ef5d610e34 Mon Sep 17 00:00:00 2001
From: Ian Chamberlain <ian.h.chamberlain@gmail.com>
Date: Sat, 23 Sep 2023 13:34:28 -0400
Subject: [PATCH] Rename to citro3d-macros

Export as pub mod macros, add tests, and refactor error handling a bit
to make the logic simpler.
---
 .gitignore                             |  3 ++
 Cargo.toml                             | 13 ++++-
 {pica200 => citro3d-macros}/Cargo.toml |  2 +-
 {pica200 => citro3d-macros}/build.rs   |  0
 {pica200 => citro3d-macros}/src/lib.rs | 66 ++++++++++++++++----------
 citro3d-macros/tests/integration.pica  | 14 ++++++
 citro3d-macros/tests/integration.rs    | 15 ++++++
 citro3d/Cargo.toml                     |  2 +-
 citro3d/src/lib.rs                     |  6 ++-
 9 files changed, 91 insertions(+), 30 deletions(-)
 rename {pica200 => citro3d-macros}/Cargo.toml (89%)
 rename {pica200 => citro3d-macros}/build.rs (100%)
 rename {pica200 => citro3d-macros}/src/lib.rs (65%)
 create mode 100644 citro3d-macros/tests/integration.pica
 create mode 100644 citro3d-macros/tests/integration.rs

diff --git a/.gitignore b/.gitignore
index 4a87a85..f13002d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,6 @@ Cargo.lock
 rust-toolchain
 rust-toolchain.toml
 .cargo/
+
+# Pica200 output files
+*.shbin
diff --git a/Cargo.toml b/Cargo.toml
index f8955b4..c2c3e84 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,15 @@
 [workspace]
-members = ["citro3d-sys", "citro3d", "bindgen-citro3d", "pica200"]
-default-members = ["citro3d", "citro3d-sys", "pica200"]
+members = [
+    "bindgen-citro3d",
+    "citro3d-macros",
+    "citro3d-sys",
+    "citro3d",
+]
+default-members = [
+    "citro3d",
+    "citro3d-sys",
+    "citro3d-macros",
+]
 resolver = "2"
 
 [patch."https://github.com/rust3ds/citro3d-rs.git"]
diff --git a/pica200/Cargo.toml b/citro3d-macros/Cargo.toml
similarity index 89%
rename from pica200/Cargo.toml
rename to citro3d-macros/Cargo.toml
index bc7c0e3..968366e 100644
--- a/pica200/Cargo.toml
+++ b/citro3d-macros/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "pica200"
+name = "citro3d-macros"
 version = "0.1.0"
 edition = "2021"
 authors = ["Rust3DS Org"]
diff --git a/pica200/build.rs b/citro3d-macros/build.rs
similarity index 100%
rename from pica200/build.rs
rename to citro3d-macros/build.rs
diff --git a/pica200/src/lib.rs b/citro3d-macros/src/lib.rs
similarity index 65%
rename from pica200/src/lib.rs
rename to citro3d-macros/src/lib.rs
index 77f195e..6fbcc3a 100644
--- a/pica200/src/lib.rs
+++ b/citro3d-macros/src/lib.rs
@@ -1,10 +1,13 @@
 // we're already nightly-only so might as well use unstable proc macro APIs.
 #![feature(proc_macro_span)]
 
+use std::error::Error;
+use std::fs::DirBuilder;
 use std::path::PathBuf;
 use std::{env, process};
 
 use litrs::StringLit;
+use proc_macro::TokenStream;
 use quote::quote;
 
 /// Compiles the given PICA200 shader using [`picasso`](https://github.com/devkitPro/picasso)
@@ -23,22 +26,30 @@ use quote::quote;
 /// # Example
 ///
 /// ```no_run
-/// # use pica200::include_shader;
+/// # use citro3d_macros::include_shader;
 /// static SHADER_BYTES: &[u8] = include_shader!("assets/vshader.pica");
 /// ```
 #[proc_macro]
 pub fn include_shader(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    match include_shader_impl(input) {
+        Ok(tokens) => tokens,
+        Err(err) => {
+            let err_str = err.to_string();
+            quote! { compile_error!( #err_str ) }.into()
+        }
+    }
+}
+
+fn include_shader_impl(input: TokenStream) -> Result<TokenStream, Box<dyn Error>> {
     let tokens: Vec<_> = input.into_iter().collect();
 
     if tokens.len() != 1 {
-        let msg = format!("expected exactly one input token, got {}", tokens.len());
-        return quote! { compile_error!(#msg) }.into();
+        return Err(format!("expected exactly one input token, got {}", tokens.len()).into());
     }
 
     let string_lit = match StringLit::try_from(&tokens[0]) {
-        // Error if the token is not a string literal
-        Err(e) => return e.to_compile_error(),
         Ok(lit) => lit,
+        Err(err) => return Ok(err.to_compile_error()),
     };
 
     // The cwd can change depending on whether this is running in a doctest or not:
@@ -46,46 +57,51 @@ pub fn include_shader(input: proc_macro::TokenStream) -> proc_macro::TokenStream
     //
     // But the span's `source_file()` seems to always be relative to the cwd.
     let cwd = env::current_dir().expect("unable to determine working directory");
-    let invoking_source_file = tokens[0].span().source_file().path();
-    let invoking_source_dir = invoking_source_file
-        .parent()
-        .expect("unable to find parent directory of invoking source file");
+    let span = tokens[0].span();
+    let invoking_source_file = span.source_file().path();
+    let Some(invoking_source_dir) = invoking_source_file.parent() else {
+        return Err("unable to find parent directory of invoking source file".into());
+    };
 
     // By joining these three pieces, we arrive at approximately the same behavior as `include_bytes!`
     let shader_source_file = cwd.join(invoking_source_dir).join(string_lit.value());
-    let shader_out_file = shader_source_file.with_extension("shbin");
-
-    let Some(shader_out_file) = shader_out_file.file_name() else {
-        let msg = format!("invalid input file name {shader_source_file:?}");
-        return quote! { compile_error!(#msg) }.into();
-    };
+    let shader_out_file: PathBuf = shader_source_file.with_extension("shbin");
 
     let out_dir = PathBuf::from(env!("OUT_DIR"));
-    let out_path = out_dir.join(shader_out_file);
+    // This might be overkill, but it ensures we get a unique path if different
+    // shaders with the same relative path are used within one program
+    let relative_out_path = shader_out_file.canonicalize()?;
+
+    let out_path = out_dir.join(
+        relative_out_path
+            .strip_prefix("/")
+            .unwrap_or(&shader_out_file),
+    );
+
+    let parent_dir = out_path.parent().ok_or("invalid input filename")?;
+    DirBuilder::new().recursive(true).create(parent_dir)?;
 
     let devkitpro = PathBuf::from(env!("DEVKITPRO"));
 
     let output = process::Command::new(devkitpro.join("tools/bin/picasso"))
         .arg("--out")
         .args([&out_path, &shader_source_file])
-        .output()
-        .unwrap();
+        .output()?;
 
     match output.status.code() {
         Some(0) => {}
         code => {
             let code = code.map_or_else(|| String::from("unknown"), |c| c.to_string());
 
-            let msg = format!(
-                "failed to compile shader {shader_source_file:?}: exit status {code}: {}",
+            return Err(format!(
+                "failed to compile shader: exit status from `picasso` was {code}: {}",
                 String::from_utf8_lossy(&output.stderr),
-            );
-
-            return quote! { compile_error!(#msg) }.into();
+            )
+            .into());
         }
     }
 
-    let bytes = std::fs::read(out_path).unwrap();
+    let bytes = std::fs::read(out_path)?;
     let source_file_path = shader_source_file.to_string_lossy();
 
     let result = quote! {
@@ -111,5 +127,5 @@ pub fn include_shader(input: proc_macro::TokenStream) -> proc_macro::TokenStream
         }
     };
 
-    result.into()
+    Ok(result.into())
 }
diff --git a/citro3d-macros/tests/integration.pica b/citro3d-macros/tests/integration.pica
new file mode 100644
index 0000000..a47bfde
--- /dev/null
+++ b/citro3d-macros/tests/integration.pica
@@ -0,0 +1,14 @@
+; Trivial vertex shader
+
+.out outpos position
+.out outclr color
+
+.alias inpos v1
+.alias inclr v0
+
+.proc main
+    mov outpos, inpos
+    mov outclr, inclr
+
+    end
+.end
diff --git a/citro3d-macros/tests/integration.rs b/citro3d-macros/tests/integration.rs
new file mode 100644
index 0000000..c67a52f
--- /dev/null
+++ b/citro3d-macros/tests/integration.rs
@@ -0,0 +1,15 @@
+use citro3d_macros::include_shader;
+
+#[test]
+fn includes_shader_static() {
+    static SHADER_BYTES: &[u8] = include_shader!("test.pica");
+
+    assert_eq!(SHADER_BYTES.len() % 4, 0);
+}
+
+#[test]
+fn includes_shader_const() {
+    const SHADER_BYTES: &[u8] = include_shader!("test.pica");
+
+    assert_eq!(SHADER_BYTES.len() % 4, 0);
+}
diff --git a/citro3d/Cargo.toml b/citro3d/Cargo.toml
index 8d94e9f..99b340c 100644
--- a/citro3d/Cargo.toml
+++ b/citro3d/Cargo.toml
@@ -6,7 +6,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-pica200 = { version = "0.1.0", path = "../pica200" }
+citro3d-macros = { version = "0.1.0", path = "../citro3d-macros" }
 bitflags = "1.3.2"
 bytemuck = { version = "1.10.0", features = ["extern_crate_std"] }
 citro3d-sys = { git = "https://github.com/rust3ds/citro3d-rs.git" }
diff --git a/citro3d/src/lib.rs b/citro3d/src/lib.rs
index cab6a59..5176de6 100644
--- a/citro3d/src/lib.rs
+++ b/citro3d/src/lib.rs
@@ -8,7 +8,11 @@ pub mod shader;
 
 use citro3d_sys::C3D_FrameDrawOn;
 pub use error::{Error, Result};
-pub use pica200::include_shader;
+
+pub mod macros {
+    //! Helper macros for working with shaders.
+    pub use citro3d_macros::*;
+}
 
 /// The single instance for using `citro3d`. This is the base type that an application
 /// should instantiate to use this library.