rustbuild: Add option for enabling partial LLVM rebuilds

appveyor.yml

@@ -144,10 +144,10 @@ on_failure:
  - cat %CD%/sccache.log
 
 cache:
- - "build/i686-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"
- - "build/x86_64-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"
- - "i686-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"
- - "x86_64-pc-windows-msvc/llvm -> src/rustllvm/llvm-auto-clean-trigger"
+ - "build/i686-pc-windows-msvc/llvm -> src/rustllvm/llvm-rebuild-trigger"
+ - "build/x86_64-pc-windows-msvc/llvm -> src/rustllvm/llvm-rebuild-trigger"
+ - "i686-pc-windows-msvc/llvm -> src/rustllvm/llvm-rebuild-trigger"
+ - "x86_64-pc-windows-msvc/llvm -> src/rustllvm/llvm-rebuild-trigger"
 
 branches:
  only:

configure

@@ -437,6 +437,7 @@ opt local-rust 0 "use an installed rustc rather than downloading a snapshot"
 opt local-rebuild 0 "assume local-rust matches the current version, for rebuilds; implies local-rust, and is implied if local-rust already matches the current version"
 opt llvm-static-stdcpp 0 "statically link to libstdc++ for LLVM"
 opt llvm-link-shared 0 "prefer shared linking to LLVM (llvm-config --link-shared)"
+opt llvm-clean-rebuild 0 "delete LLVM build directory on rebuild"
 opt rpath 1 "build rpaths into rustc itself"
 opt stage0-landing-pads 1 "enable landing pads during bootstrap with stage0"
 # This is used by the automation to produce single-target nightlies

src/bootstrap/config.rs

@@ -60,6 +60,7 @@ pub struct Config {
  pub llvm_link_shared: bool,
  pub llvm_targets: Option<String>,
  pub llvm_link_jobs: Option<u32>,
+ pub llvm_clean_rebuild: bool,
 
  // rust codegen options
  pub rust_optimize: bool,
@@ -181,6 +182,7 @@ struct Llvm {
  static_libstdcpp: Option<bool>,
  targets: Option<String>,
  link_jobs: Option<u32>,
+ clean_rebuild: Option<bool>,
 }
 
 #[derive(RustcDecodable, Default, Clone)]
@@ -334,6 +336,7 @@ impl Config {
  set(&mut config.llvm_release_debuginfo, llvm.release_debuginfo);
  set(&mut config.llvm_version_check, llvm.version_check);
  set(&mut config.llvm_static_stdcpp, llvm.static_libstdcpp);
+ set(&mut config.llvm_clean_rebuild, llvm.clean_rebuild);
  config.llvm_targets = llvm.targets.clone();
  config.llvm_link_jobs = llvm.link_jobs;
  }
@@ -439,6 +442,7 @@ impl Config {
  ("LLVM_VERSION_CHECK", self.llvm_version_check),
  ("LLVM_STATIC_STDCPP", self.llvm_static_stdcpp),
  ("LLVM_LINK_SHARED", self.llvm_link_shared),
+ ("LLVM_CLEAN_REBUILD", self.llvm_clean_rebuild),
  ("OPTIMIZE", self.rust_optimize),
  ("DEBUG_ASSERTIONS", self.rust_debug_assertions),
  ("DEBUGINFO", self.rust_debuginfo),

src/bootstrap/config.toml.example

@@ -61,6 +61,11 @@
 # controlled by rustbuild's -j parameter.
 #link-jobs = 0
 
+# Delete LLVM build directory on LLVM rebuild.
+# This option defaults to `false` for local development, but CI may want to
+# always perform clean full builds (possibly accelerated by (s)ccache).
+#clean-rebuild = false
+
 # =============================================================================
 # General build configuration options
 # =============================================================================

src/bootstrap/native.rs

@@ -41,28 +41,25 @@ pub fn llvm(build: &Build, target: &str) {
  }
  }
 
- let clean_trigger = build.src.join("src/rustllvm/llvm-auto-clean-trigger");
- let mut clean_trigger_contents = String::new();
- t!(t!(File::open(&clean_trigger)).read_to_string(&mut clean_trigger_contents));
+ let rebuild_trigger = build.src.join("src/rustllvm/llvm-rebuild-trigger");
+ let mut rebuild_trigger_contents = String::new();
+ t!(t!(File::open(&rebuild_trigger)).read_to_string(&mut rebuild_trigger_contents));
 
  let out_dir = build.llvm_out(target);
  let done_stamp = out_dir.join("llvm-finished-building");
  if done_stamp.exists() {
  let mut done_contents = String::new();
  t!(t!(File::open(&done_stamp)).read_to_string(&mut done_contents));
 
- // LLVM was already built previously.
- // We don't track changes in LLVM sources, so we need to choose between reusing
- // what was built previously, or cleaning the directory and doing a fresh build.
- // The choice depends on contents of the clean-trigger file.
- // If the contents are the same as during the previous build, then no action is required.
- // If the contents differ from the previous build, then cleaning is triggered.
- if done_contents == clean_trigger_contents {
+ // If LLVM was already built previously and contents of the rebuild-trigger file
+ // didn't change from the previous build, then no action is required.
+ if done_contents == rebuild_trigger_contents {
  return
- } else {
- t!(fs::remove_dir_all(&out_dir));
  }
  }
+ if build.config.llvm_clean_rebuild {
+ drop(fs::remove_dir_all(&out_dir));
+ }
 
  println!("Building LLVM for {}", target);
  let _time = util::timeit();
@@ -154,7 +151,7 @@ pub fn llvm(build: &Build, target: &str) {
  // tools and libs on all platforms.
  cfg.build();
 
- t!(t!(File::create(&done_stamp)).write_all(clean_trigger_contents.as_bytes()));
+ t!(t!(File::create(&done_stamp)).write_all(rebuild_trigger_contents.as_bytes()));
 }
 
 fn check_llvm_version(build: &Build, llvm_config: &Path) {

src/ci/run.sh

@@ -28,6 +28,7 @@ RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-quiet-tests"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-manage-submodules"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-locked-deps"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-cargo-openssl-static"
+RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-llvm-clean-rebuild"
 
 if [ "$DIST_SRC" = "" ]; then
  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-dist-src"

src/rustllvm/llvm-auto-clean-trigger → src/rustllvm/llvm-rebuild-trigger

@@ -1,4 +1,4 @@
-# If this file is modified, then llvm will be forcibly cleaned and then rebuilt.
+# If this file is modified, then llvm will be (optionally) cleaned and then rebuilt.
 # The actual contents of this file do not matter, but to trigger a change on the
 # build bots then the contents should be changed so git updates the mtime.
 2017-03-04