Bootstrap: Add argument for building llvm bitcode linker

Author: Kjetil Kjeka

config.example.toml

@@ -679,6 +679,10 @@
 # sysroot.
 #llvm-tools = true
 
+# Indicates whether the `self-contained` llvm-bitcode-linker, will be made available
+# in the sysroot
+#llvm-bitcode-linker = false
+
 # Whether to deny warnings in crates
 #deny-warnings = true
 

src/bootstrap/configure.py

@@ -54,6 +54,7 @@ def v(*args):
 o("profiler", "build.profiler", "build the profiler runtime")
 o("full-tools", None, "enable all tools")
 o("lld", "rust.lld", "build lld")
+o("llvm-bitcode-linker", "rust.llvm-bitcode-linker", "build llvm bitcode linker")
 o("clang", "llvm.clang", "build clang")
 o("use-libcxx", "llvm.use-libcxx", "build LLVM with libc++")
 o("control-flow-guard", "rust.control-flow-guard", "Enable Control Flow Guard")
@@ -366,6 +367,7 @@ def apply_args(known_args, option_checking, config):
             set('rust.codegen-backends', ['llvm'], config)
             set('rust.lld', True, config)
             set('rust.llvm-tools', True, config)
+            set('rust.llvm-bitcode-linker', True, config)
             set('build.extended', True, config)
         elif option.name in ['option-checking', 'verbose-configure']:
             # this was handled above

src/bootstrap/defaults/config.compiler.toml

@@ -17,6 +17,8 @@ lto = "off"
 # Forces frame pointers to be used with `-Cforce-frame-pointers`.
 # This can be helpful for profiling at a small performance cost.
 frame-pointers = true
+# Build the llvm-bitcode-linker as it is required for running nvptx tests
+llvm-bitcode-linker = true
 
 [llvm]
 # Having this set to true disrupts compiler development workflows for people who use `llvm.download-ci-llvm = true`

src/bootstrap/defaults/config.dist.toml

@@ -16,6 +16,8 @@ download-ci-llvm = false
 # Make sure they don't get set when installing from source.
 channel = "nightly"
 download-rustc = false
+# Build the llvm-bitcode-linker as it is required for running nvptx tests
+llvm-bitcode-linker = true
 
 [dist]
 # Use better compression when preparing tarballs.

src/bootstrap/defaults/config.library.toml

@@ -10,6 +10,8 @@ bench-stage = 0
 incremental = true
 # Make the compiler and standard library faster to build, at the expense of a ~20% runtime slowdown.
 lto = "off"
+# Build the llvm-bitcode-linker as it is required for running nvptx tests
+llvm-bitcode-linker = true
 
 [llvm]
 # Will download LLVM from CI if available on your platform.

src/bootstrap/defaults/config.tools.toml

@@ -12,6 +12,8 @@ incremental = true
 # Using these defaults will download the stage2 compiler (see `download-rustc`
 # setting) and the stage2 toolchain should therefore be used for these defaults.
 download-rustc = "if-unchanged"
+# Build the llvm-bitcode-linker as it is required for running nvptx tests
+llvm-bitcode-linker = true
 
 [build]
 # Document with the in-tree rustdoc by default, since `download-rustc` makes it quick to compile.

src/bootstrap/src/core/build_steps/compile.rs

@@ -1844,6 +1844,16 @@ impl Step for Assemble {
             }
         }
 
+        if builder.config.llvm_bitcode_linker_enabled {
+            let src_path = builder.ensure(crate::core::build_steps::tool::LlvmBitcodeLinker {
+                compiler: build_compiler,
+                target: target_compiler.host,
+                extra_features: vec![],
+            });
+            let tool_exe = exe("llvm-bitcode-linker", target_compiler.host);
+            builder.copy(&src_path, &libdir_bin.join(&tool_exe));
+        }
+
         // Ensure that `libLLVM.so` ends up in the newly build compiler directory,
         // so that it can be found when the newly built `rustc` is run.
         dist::maybe_install_llvm_runtime(builder, target_compiler.host, &sysroot);

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

@@ -236,6 +236,7 @@ pub struct Config {
     pub lld_mode: LldMode,
     pub lld_enabled: bool,
     pub llvm_tools_enabled: bool,
+    pub llvm_bitcode_linker_enabled: bool,
 
     pub llvm_cflags: Option<String>,
     pub llvm_cxxflags: Option<String>,
@@ -1096,6 +1097,7 @@ define_config! {
         dist_src: Option<bool> = "dist-src",
         save_toolstates: Option<String> = "save-toolstates",
         codegen_backends: Option<Vec<String>> = "codegen-backends",
+        llvm_bitcode_linker: Option<bool> = "llvm-bitcode-linker",
         lld: Option<bool> = "lld",
         lld_mode: Option<LldMode> = "use-lld",
         llvm_tools: Option<bool> = "llvm-tools",
@@ -1567,6 +1569,7 @@ impl Config {
                 codegen_backends,
                 lld,
                 llvm_tools,
+                llvm_bitcode_linker,
                 deny_warnings,
                 backtrace_on_ice,
                 verify_llvm_ir,
@@ -1646,6 +1649,7 @@ impl Config {
             }
             set(&mut config.lld_mode, lld_mode);
             set(&mut config.lld_enabled, lld);
+            set(&mut config.llvm_bitcode_linker_enabled, llvm_bitcode_linker);
 
             if matches!(config.lld_mode, LldMode::SelfContained)
                 && !config.lld_enabled

src/bootstrap/src/utils/change_tracker.rs

@@ -141,4 +141,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Info,
         summary: "A new `boostrap-cache-path` option has been introduced which can be utilized to modify the cache path for bootstrap.",
     },
+    ChangeInfo {
+        change_id: 117458,
+        severity: ChangeSeverity::Info,
+        summary: "New option `rust.llvm-bitcode-linker` that will build the llvm-bitcode-linker.",
+    },
 ];

src/ci/docker/host-x86_64/dist-various-2/Dockerfile

@@ -135,7 +135,7 @@ ENV TARGETS=$TARGETS,x86_64-unknown-uefi
 # Luckily one of the folders is /usr/local/include so symlink /usr/include/x86_64-linux-gnu/asm there
 RUN ln -s /usr/include/x86_64-linux-gnu/asm /usr/local/include/asm
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --disable-docs \
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --enable-llvm-bitcode-linker --disable-docs \
   --set target.wasm32-wasi.wasi-root=/wasm32-wasip1 \
   --set target.wasm32-wasip1.wasi-root=/wasm32-wasip1 \
   --set target.wasm32-wasi-preview1-threads.wasi-root=/wasm32-wasi-preview1-threads \