rusticl/program: add debugging for OpenCL C compilation

Signed-off-by: Karol Herbst <git@karolherbst.de>
Reviewed-by: Nora Allen <blackcatgames@protonmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23818>

docs/envvars.rst

@@ -945,6 +945,7 @@ Rusticl environment variables
 
    a comma-separated list of debug channels to enable.
 
+   - ``clc`` dumps all OpenCL C source being compiled
    - ``program`` dumps compilation logs to stderr
 
 .. _clc-env-var:

src/gallium/frontends/rusticl/core/platform.rs

@@ -17,6 +17,7 @@ pub struct Platform {
 }
 
 pub struct PlatformDebug {
+    pub clc: bool,
     pub program: bool,
 }
 
@@ -55,7 +56,10 @@ static mut PLATFORM: Platform = Platform {
     dispatch: &DISPATCH,
     devs: Vec::new(),
 };
-static mut PLATFORM_DBG: PlatformDebug = PlatformDebug { program: false };
+static mut PLATFORM_DBG: PlatformDebug = PlatformDebug {
+    clc: false,
+    program: false,
+};
 static mut PLATFORM_FEATURES: PlatformFeatures = PlatformFeatures {
     fp16: false,
     fp64: false,
@@ -66,6 +70,7 @@ fn load_env() {
     if let Ok(debug_flags) = env::var("RUSTICL_DEBUG") {
         for flag in debug_flags.split(',') {
             match flag {
+                "clc" => debug.clc = true,
                 "program" => debug.program = true,
                 _ => eprintln!("Unknown RUSTICL_DEBUG flag found: {}", flag),
             }

src/gallium/frontends/rusticl/core/program.rs

@@ -563,6 +563,17 @@ impl Program {
             }
             ProgramSourceType::Src(src) => {
                 let args = prepare_options(&options, dev);
+
+                if Platform::dbg().clc {
+                    let src = src.to_string_lossy();
+                    eprintln!("dumping compilation inputs:");
+                    eprintln!("compilation arguments: {args:?}");
+                    if !headers.is_empty() {
+                        eprintln!("headers: {headers:#?}");
+                    }
+                    eprintln!("source code:\n{src}");
+                }
+
                 spirv::SPIRVBin::from_clc(
                     src,
                     &args,

src/gallium/frontends/rusticl/mesa/compiler/clc/spirv.rs

@@ -7,6 +7,7 @@ use mesa_rust_util::serialize::*;
 use mesa_rust_util::string::*;
 
 use std::ffi::CString;
+use std::fmt::Debug;
 use std::os::raw::c_char;
 use std::os::raw::c_void;
 use std::ptr;
@@ -37,6 +38,15 @@ pub struct CLCHeader<'a> {
     pub source: &'a CString,
 }
 
+impl<'a> Debug for CLCHeader<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let name = self.name.to_string_lossy();
+        let source = self.source.to_string_lossy();
+
+        f.write_fmt(format_args!("[{name}]:\n{source}"))
+    }
+}
+
 unsafe fn callback_impl(data: *mut c_void, msg: *const c_char) {
     let data = data as *mut Vec<String>;
     let msgs = unsafe { data.as_mut() }.unwrap();