From fbe9a7ca3e78b683266dac706d156c110dcefdfc Mon Sep 17 00:00:00 2001
From: Karol Herbst <kherbst@redhat.com>
Date: Wed, 1 Mar 2023 00:39:25 +0100
Subject: [PATCH] rusticl/mesa: create proper build-id hash for the disk cache

Without generating a proper timestamp for the disk cache, we pull old
binaries out of the disk cache, potentially being buggy or simply
outdated.

Once meson 1.2 lands we can easily pull in LLVM functions.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Nora Allen <blackcatgames@protonmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21612>
---
 src/gallium/frontends/rusticl/core/program.rs |  6 ++++-
 .../frontends/rusticl/mesa/util/disk_cache.rs | 26 ++++++++++++++++---
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/gallium/frontends/rusticl/core/program.rs b/src/gallium/frontends/rusticl/core/program.rs
index fe0403203f9..2df9d9ab574 100644
--- a/src/gallium/frontends/rusticl/core/program.rs
+++ b/src/gallium/frontends/rusticl/core/program.rs
@@ -40,9 +40,13 @@ static mut DISK_CACHE: Option<DiskCache> = None;
 static DISK_CACHE_ONCE: Once = Once::new();
 
 fn get_disk_cache() -> &'static Option<DiskCache> {
+    let func_ptrs = [
+        // ourselves
+        get_disk_cache as _,
+    ];
     unsafe {
         DISK_CACHE_ONCE.call_once(|| {
-            DISK_CACHE = DiskCache::new("rusticl", "rusticl", 0);
+            DISK_CACHE = DiskCache::new("rusticl", &func_ptrs, 0);
         });
         &DISK_CACHE
     }
diff --git a/src/gallium/frontends/rusticl/mesa/util/disk_cache.rs b/src/gallium/frontends/rusticl/mesa/util/disk_cache.rs
index 55f7dbd60b8..d07d57ed071 100644
--- a/src/gallium/frontends/rusticl/mesa/util/disk_cache.rs
+++ b/src/gallium/frontends/rusticl/mesa/util/disk_cache.rs
@@ -1,6 +1,6 @@
 use mesa_rust_gen::*;
 
-use std::ffi::CString;
+use std::ffi::{c_void, CString};
 use std::ops::Deref;
 use std::ptr;
 use std::ptr::NonNull;
@@ -74,10 +74,28 @@ impl DiskCacheBorrowed {
 }
 
 impl DiskCache {
-    pub fn new(name: &str, driver_id: &str, flags: u64) -> Option<Self> {
+    pub fn new(name: &str, func_ptrs: &[*mut c_void], flags: u64) -> Option<Self> {
         let c_name = CString::new(name).unwrap();
-        let c_id = CString::new(driver_id).unwrap();
-        let cache = unsafe { disk_cache_create(c_name.as_ptr(), c_id.as_ptr(), flags) };
+        let mut sha_ctx = SHA1_CTX::default();
+        let mut sha = [0; SHA1_DIGEST_LENGTH as usize];
+        let mut cache_id = [0; SHA1_DIGEST_STRING_LENGTH as usize];
+
+        let cache = unsafe {
+            SHA1Init(&mut sha_ctx);
+
+            for &func_ptr in func_ptrs {
+                if !disk_cache_get_function_identifier(func_ptr, &mut sha_ctx) {
+                    return None;
+                }
+            }
+            SHA1Final(&mut sha, &mut sha_ctx);
+            mesa_bytes_to_hex(
+                cache_id.as_mut_ptr(),
+                sha.as_ptr(),
+                (cache_id.len() - 1) as u32,
+            );
+            disk_cache_create(c_name.as_ptr(), cache_id.as_ptr(), flags)
+        };
 
         DiskCacheBorrowed::from_ptr(cache).map(|c| Self { inner: c })
     }