build.rs: don't build compile-shaders if shaders are unchanged

Cargo.lock

@@ -637,6 +637,7 @@ dependencies = [
  "tiny-skia",
  "tracy-client-sys",
  "uapi",
+ "walkdir",
  "with_builtin_macros",
 ]
 

Cargo.toml

@@ -74,6 +74,8 @@ repc = "0.1.1"
 anyhow = "1.0.79"
 bstr = { version = "1.9.0", default-features = false, features = ["std"] }
 cc = "1.0.86"
+blake3 = "1.8.2"
+walkdir = "2.5.0"
 
 #[profile.dev.build-override]
 #opt-level = 3

build/vulkan.rs

@@ -1,9 +1,14 @@
-use {anyhow::bail, std::process::Command};
+mod hash;
+
+use {crate::vulkan::hash::unchanged, anyhow::bail, std::process::Command};
 
 pub fn main() -> anyhow::Result<()> {
     if !std::fs::exists("compile-shaders")? {
         return Ok(());
     }
+    if unchanged() {
+        return Ok(());
+    }
     let code = Command::new("cargo")
         .args([
             "run",

build/vulkan/hash.rs

@@ -0,0 +1,32 @@
+use {std::fmt::Write, walkdir::WalkDir};
+
+pub const ROOT: &str = "src/gfx_apis/vulkan/shaders";
+pub const HASH: &str = "src/gfx_apis/vulkan/shaders_hash.txt";
+
+fn calculate_hash() -> anyhow::Result<String> {
+    let dir = WalkDir::new(ROOT);
+    let mut files = vec![];
+    for file in dir {
+        let file = file?;
+        if file.file_type().is_file() {
+            files.push(file.path().to_path_buf());
+        }
+    }
+    files.sort();
+    let mut out = String::new();
+    for file in files {
+        let data = std::fs::read(&file)?;
+        writeln!(out, "{} {}", blake3::hash(&data).to_hex(), file.display())?;
+    }
+    Ok(out)
+}
+
+pub fn unchanged() -> bool {
+    let Ok(actual) = std::fs::read_to_string(HASH) else {
+        return false;
+    };
+    let Ok(expected) = calculate_hash() else {
+        return false;
+    };
+    actual == expected
+}

compile-shaders/build-rs/src/main.rs

@@ -1,14 +1,7 @@
-use {
-    anyhow::bail,
-    compile_shaders_core::{ROOT, unchanged},
-    std::process::Command,
-};
+use {anyhow::bail, compile_shaders_core::ROOT, std::process::Command};
 
 fn main() -> anyhow::Result<()> {
     println!("cargo:rerun-if-changed={}", ROOT);
-    if unchanged() {
-        return Ok(());
-    }
     let code = Command::new("cargo")
         .args([
             "run",

compile-shaders/core/src/lib.rs

@@ -1,36 +1,6 @@
-use {std::fmt::Write, walkdir::WalkDir};
+include!("../../../build/vulkan/hash.rs");
 
-pub const ROOT: &str = "src/gfx_apis/vulkan/shaders";
 pub const BIN: &str = "src/gfx_apis/vulkan/shaders_bin";
-pub const HASH: &str = "src/gfx_apis/vulkan/shaders_hash.txt";
-
-fn calculate_hash() -> anyhow::Result<String> {
-    let dir = WalkDir::new(ROOT);
-    let mut files = vec![];
-    for file in dir {
-        let file = file?;
-        if file.file_type().is_file() {
-            files.push(file.path().to_path_buf());
-        }
-    }
-    files.sort();
-    let mut out = String::new();
-    for file in files {
-        let data = std::fs::read(&file)?;
-        writeln!(out, "{} {}", blake3::hash(&data).to_hex(), file.display())?;
-    }
-    Ok(out)
-}
-
-pub fn unchanged() -> bool {
-    let Ok(actual) = std::fs::read_to_string(HASH) else {
-        return false;
-    };
-    let Ok(expected) = calculate_hash() else {
-        return false;
-    };
-    actual == expected
-}
 
 pub fn update_hash() -> anyhow::Result<()> {
     std::fs::write(HASH, calculate_hash()?)?;