worked locally with setting LLVM_ROOT and cc/cxx

Author: ZuseZ4

src/bootstrap/src/core/build_steps/llvm.rs

@@ -971,12 +971,20 @@ impl Step for OmpOffload {
         } else {
             builder.cxx(target).unwrap()
         };
+        let root = if let Some(p) = &builder.build.config.llvm_root_offload {
+            p.clone()
+        } else {
+            builder.llvm_out(target).join("build")
+        };
 
         cfg.out_dir(&out_dir)
             .profile(profile)
             .env("LLVM_CONFIG_REAL", &host_llvm_config)
             .define("LLVM_ENABLE_ASSERTIONS", "ON")
             .define("LLVM_ENABLE_RUNTIMES", "openmp;offload")
+            .define("LLVM_INCLUDE_TESTS", "OFF")
+            .define("LLVM_BUILD_TESTS", "OFF")
+            .define("OFFLOAD_INCLUDE_TESTS", "OFF")
             //.define(
             //    "CMAKE_C_COMPILER",
             //    "/tmp/drehwald1/prog/rust/build/x86_64-unknown-linux-gnu/llvm/bin/clang",
@@ -987,16 +995,17 @@ impl Step for OmpOffload {
             //)
             .define("CMAKE_C_COMPILER", cc)
             .define("CMAKE_CXX_COMPILER", cxx)
+            .define("Clang_DIR", "/tmp/drehwald1/prog/llvm/lib/cmake/clang")
             .define("OPENMP_STANDALONE_BUILD", "ON")
-            .define("LLVM_ROOT", builder.llvm_out(target).join("build"))
+            .define("LLVM_ROOT", root)
             //.define(
             //    "LLVM_ROOT",
             //    "/tmp/drehwald1/prog/rust/build/x86_64-unknown-linux-gnu/llvm/build/",
             //)
             .define("LLVM_DIR", builder.llvm_out(target).join("lib").join("cmake").join("llvm"));
         cfg.build();
 
-        //t!(stamp.write());
+        t!(stamp.write());
         out_dir
     }
 }

src/bootstrap/src/core/config/config.rs

@@ -171,6 +171,7 @@ pub struct Config {
     pub llvm_use_linker: Option<String>,
     pub llvm_offload_cc: Option<PathBuf>,
     pub llvm_offload_cxx: Option<PathBuf>,
+    pub llvm_root_offload: Option<PathBuf>,
     pub llvm_allow_old_toolchain: bool,
     pub llvm_polly: bool,
     pub llvm_clang: bool,
@@ -606,6 +607,7 @@ impl Config {
             use_linker: llvm_use_linker,
             offload_cc: llvm_offload_cc,
             offload_cxx: llvm_offload_cxx,
+            root_offload: llvm_root_offload,
             allow_old_toolchain: llvm_allow_old_toolchain,
             offload: llvm_offload,
             polly: llvm_polly,
@@ -1370,6 +1372,7 @@ impl Config {
             llvm_experimental_targets,
             llvm_offload_cc: llvm_offload_cc.map(PathBuf::from),
             llvm_offload_cxx: llvm_offload_cxx.map(PathBuf::from),
+            llvm_root_offload: llvm_root_offload.map(PathBuf::from),
             llvm_from_ci,
             llvm_ldflags,
             llvm_libunwind_default: rust_llvm_libunwind

src/bootstrap/src/core/config/toml/llvm.rs

@@ -34,6 +34,7 @@ define_config! {
         use_linker: Option<String> = "use-linker",
         offload_cc: Option<String> = "offload-cc",
         offload_cxx: Option<String> = "offload-cxx",
+        root_offload: Option<String> = "root-offload",
         allow_old_toolchain: Option<bool> = "allow-old-toolchain",
         offload: Option<bool> = "offload",
         polly: Option<bool> = "polly",
@@ -114,6 +115,7 @@ pub fn check_incompatible_options_for_ci_llvm(
         use_linker,
         offload_cc,
         offload_cxx,
+        root_offload,
         allow_old_toolchain,
         offload,
         polly,