diff options
| -rw-r--r-- | src/librustc/session/config.rs | 97 | ||||
| -rw-r--r-- | src/librustc_trans/back/link.rs | 2 | ||||
| -rw-r--r-- | src/librustc_trans/back/write.rs | 11 | ||||
| -rw-r--r-- | src/librustc_trans/base.rs | 4 | ||||
| -rw-r--r-- | src/test/run-make/codegen-options-parsing/Makefile | 30 | ||||
| -rw-r--r-- | src/test/run-make/llvm-phase/test.rs | 1 |
6 files changed, 97 insertions, 48 deletions
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index d3256357941..0390e222348 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -350,6 +350,9 @@ top_level_options!( // is currently just a hack and will be removed eventually, so please // try to not rely on this too much. actually_rustdoc: bool [TRACKED], + + // Number of object files/codegen units to produce on the backend + codegen_units: usize [UNTRACKED], } ); @@ -512,6 +515,7 @@ pub fn basic_options() -> Options { unstable_features: UnstableFeatures::Disallow, debug_assertions: true, actually_rustdoc: false, + codegen_units: 1, } } @@ -529,11 +533,6 @@ impl Options { (self.debugging_opts.query_dep_graph || self.debugging_opts.incremental_info) } - pub fn single_codegen_unit(&self) -> bool { - self.incremental.is_none() || - self.cg.codegen_units == 1 - } - pub fn file_path_mapping(&self) -> FilePathMapping { FilePathMapping::new( self.debugging_opts.remap_path_prefix_from.iter().zip( @@ -791,7 +790,7 @@ macro_rules! options { fn parse_opt_uint(slot: &mut Option<usize>, v: Option<&str>) -> bool { match v { Some(s) => { *slot = s.parse().ok(); slot.is_some() } - None => { *slot = None; true } + None => { *slot = None; false } } } @@ -924,7 +923,7 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options, "metadata to mangle symbol names with"), extra_filename: String = ("".to_string(), parse_string, [UNTRACKED], "extra data to put in each output filename"), - codegen_units: usize = (1, parse_uint, [UNTRACKED], + codegen_units: Option<usize> = (None, parse_opt_uint, [UNTRACKED], "divide crate into N units to optimize in parallel"), remark: Passes = (SomePasses(Vec::new()), parse_passes, [UNTRACKED], "print remarks for these optimization passes (space separated, or \"all\")"), @@ -1521,27 +1520,35 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches) } let mut cg = build_codegen_options(matches, error_format); + let mut codegen_units = cg.codegen_units; // Issue #30063: if user requests llvm-related output to one // particular path, disable codegen-units. - if matches.opt_present("o") && cg.codegen_units != 1 { - let incompatible: Vec<_> = output_types.iter() - .map(|ot_path| ot_path.0) - .filter(|ot| { - !ot.is_compatible_with_codegen_units_and_single_output_file() - }).collect(); - if !incompatible.is_empty() { - for ot in &incompatible { - early_warn(error_format, &format!("--emit={} with -o incompatible with \ - -C codegen-units=N for N > 1", - ot.shorthand())); + let incompatible: Vec<_> = output_types.iter() + .map(|ot_path| ot_path.0) + .filter(|ot| { + !ot.is_compatible_with_codegen_units_and_single_output_file() + }) + .map(|ot| ot.shorthand()) + .collect(); + if !incompatible.is_empty() { + match codegen_units { + Some(n) if n > 1 => { + if matches.opt_present("o") { + for ot in &incompatible { + early_warn(error_format, &format!("--emit={} with -o incompatible with \ + -C codegen-units=N for N > 1", + ot)); + } + early_warn(error_format, "resetting to default -C codegen-units=1"); + codegen_units = Some(1); + } } - early_warn(error_format, "resetting to default -C codegen-units=1"); - cg.codegen_units = 1; + _ => codegen_units = Some(1), } } - if cg.codegen_units < 1 { + if codegen_units == Some(0) { early_error(error_format, "Value for codegen units must be a positive nonzero integer"); } @@ -1550,12 +1557,17 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches) // case, but it would be confusing to have the validity of // `-Z lto -C codegen-units=2` depend on details of the crate being // compiled, so we complain regardless. - if cg.lto && cg.codegen_units > 1 { - // This case is impossible to handle because LTO expects to be able - // to combine the entire crate and all its dependencies into a - // single compilation unit, but each codegen unit is in a separate - // LLVM context, so they can't easily be combined. - early_error(error_format, "can't perform LTO when using multiple codegen units"); + if cg.lto { + if let Some(n) = codegen_units { + if n > 1 { + // This case is impossible to handle because LTO expects to be able + // to combine the entire crate and all its dependencies into a + // single compilation unit, but each codegen unit is in a separate + // LLVM context, so they can't easily be combined. + early_error(error_format, "can't perform LTO when using multiple codegen units"); + } + } + codegen_units = Some(1); } if cg.lto && debugging_opts.incremental.is_some() { @@ -1720,6 +1732,34 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches) let incremental = debugging_opts.incremental.as_ref().map(|m| PathBuf::from(m)); + let codegen_units = codegen_units.unwrap_or_else(|| { + match opt_level { + // If we're compiling at `-O0` then default to 32 codegen units. + // The number here shouldn't matter too too much as debug mode + // builds don't rely on performance at all, meaning that lost + // opportunities for inlining through multiple codegen units is + // a non-issue. + // + // Note that the high number here doesn't mean that we'll be + // spawning a large number of threads in parallel. The backend + // of rustc contains global rate limiting through the + // `jobserver` crate so we'll never overload the system with too + // much work, but rather we'll only be optimizing when we're + // otherwise cooperating with other instances of rustc. + // + // Rather the high number here means that we should be able to + // keep a lot of idle cpus busy. By ensuring that no codegen + // unit takes *too* long to build we'll be guaranteed that all + // cpus will finish pretty closely to one another and we should + // make relatively optimal use of system resources + OptLevel::No => 32, + + // All other optimization levels default use one codegen unit, + // the historical default in Rust for a Long Time. + _ => 1, + } + }); + (Options { crate_types, optimize: opt_level, @@ -1744,6 +1784,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches) unstable_features: UnstableFeatures::from_environment(), debug_assertions, actually_rustdoc: false, + codegen_units, }, cfg) } @@ -2447,7 +2488,7 @@ mod tests { opts.cg.extra_filename = String::from("extra-filename"); assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash()); - opts.cg.codegen_units = 42; + opts.cg.codegen_units = Some(42); assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash()); opts.cg.remark = super::SomePasses(vec![String::from("pass1"), diff --git a/src/librustc_trans/back/link.rs b/src/librustc_trans/back/link.rs index 1630e775991..2cf0a32d5af 100644 --- a/src/librustc_trans/back/link.rs +++ b/src/librustc_trans/back/link.rs @@ -509,7 +509,7 @@ fn link_rlib<'a>(sess: &'a Session, // of when we do and don't keep .#module-name#.bc files around. let user_wants_numbered_bitcode = sess.opts.output_types.contains_key(&OutputType::Bitcode) && - sess.opts.cg.codegen_units > 1; + sess.opts.codegen_units > 1; if !sess.opts.cg.save_temps && !user_wants_numbered_bitcode { remove(sess, &bc_filename); } diff --git a/src/librustc_trans/back/write.rs b/src/librustc_trans/back/write.rs index ef6bf2504f3..6b980a37ac7 100644 --- a/src/librustc_trans/back/write.rs +++ b/src/librustc_trans/back/write.rs @@ -939,10 +939,10 @@ fn produce_final_output_artifacts(sess: &Session, let needs_crate_object = crate_output.outputs.contains_key(&OutputType::Exe); let keep_numbered_bitcode = needs_crate_bitcode || - (user_wants_bitcode && sess.opts.cg.codegen_units > 1); + (user_wants_bitcode && sess.opts.codegen_units > 1); let keep_numbered_objects = needs_crate_object || - (user_wants_objects && sess.opts.cg.codegen_units > 1); + (user_wants_objects && sess.opts.codegen_units > 1); for module in compiled_modules.modules.iter() { let module_name = Some(&module.name[..]); @@ -1520,6 +1520,11 @@ fn start_executing_work(tcx: TyCtxt, total_llvm_time); } + // Regardless of what order these modules completed in, report them to + // the backend in the same order every time to ensure that we're handing + // out deterministic results. + compiled_modules.sort_by(|a, b| a.name.cmp(&b.name)); + let compiled_metadata_module = compiled_metadata_module .expect("Metadata module not compiled?"); @@ -1853,7 +1858,7 @@ impl OngoingCrateTranslation { // FIXME: time_llvm_passes support - does this use a global context or // something? - if sess.opts.cg.codegen_units == 1 && sess.time_llvm_passes() { + if sess.opts.codegen_units == 1 && sess.time_llvm_passes() { unsafe { llvm::LLVMRustPrintPassTimings(); } } diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs index 2d01d2947d6..774acc81343 100644 --- a/src/librustc_trans/base.rs +++ b/src/librustc_trans/base.rs @@ -1162,7 +1162,7 @@ fn collect_and_partition_translation_items<'a, 'tcx>( let strategy = if tcx.sess.opts.debugging_opts.incremental.is_some() { PartitioningStrategy::PerModule } else { - PartitioningStrategy::FixedUnitCount(tcx.sess.opts.cg.codegen_units) + PartitioningStrategy::FixedUnitCount(tcx.sess.opts.codegen_units) }; let codegen_units = time(time_passes, "codegen unit partitioning", || { @@ -1175,7 +1175,7 @@ fn collect_and_partition_translation_items<'a, 'tcx>( .collect::<Vec<_>>() }); - assert!(tcx.sess.opts.cg.codegen_units == codegen_units.len() || + assert!(tcx.sess.opts.codegen_units == codegen_units.len() || tcx.sess.opts.debugging_opts.incremental.is_some()); let translation_items: DefIdSet = items.iter().filter_map(|trans_item| { diff --git a/src/test/run-make/codegen-options-parsing/Makefile b/src/test/run-make/codegen-options-parsing/Makefile index dc46a8a04ef..755e211a349 100644 --- a/src/test/run-make/codegen-options-parsing/Makefile +++ b/src/test/run-make/codegen-options-parsing/Makefile @@ -1,26 +1,28 @@ -include ../tools.mk +LOG = $(TMPDIR)/log.txt + all: #Option taking a number - $(RUSTC) -C codegen-units dummy.rs 2>&1 | \ - grep 'codegen option `codegen-units` requires a number' - $(RUSTC) -C codegen-units= dummy.rs 2>&1 | \ - grep 'incorrect value `` for codegen option `codegen-units` - a number was expected' - $(RUSTC) -C codegen-units=foo dummy.rs 2>&1 | \ - grep 'incorrect value `foo` for codegen option `codegen-units` - a number was expected' + $(RUSTC) -C codegen-units dummy.rs 2>&1 | tee $(LOG) + grep 'codegen option `codegen-units` requires a number' $(LOG) + $(RUSTC) -C codegen-units= dummy.rs 2>&1 | tee $(LOG) + grep 'incorrect value `` for codegen option `codegen-units` - a number was expected' $(LOG) + $(RUSTC) -C codegen-units=foo dummy.rs 2>&1 | tee $(LOG) + grep 'incorrect value `foo` for codegen option `codegen-units` - a number was expected' $(LOG) $(RUSTC) -C codegen-units=1 dummy.rs #Option taking a string - $(RUSTC) -C extra-filename dummy.rs 2>&1 | \ - grep 'codegen option `extra-filename` requires a string' + $(RUSTC) -C extra-filename dummy.rs 2>&1 | tee $(LOG) + grep 'codegen option `extra-filename` requires a string' $(LOG) $(RUSTC) -C extra-filename= dummy.rs 2>&1 $(RUSTC) -C extra-filename=foo dummy.rs 2>&1 #Option taking no argument - $(RUSTC) -C lto= dummy.rs 2>&1 | \ - grep 'codegen option `lto` takes no value' - $(RUSTC) -C lto=1 dummy.rs 2>&1 | \ - grep 'codegen option `lto` takes no value' - $(RUSTC) -C lto=foo dummy.rs 2>&1 | \ - grep 'codegen option `lto` takes no value' + $(RUSTC) -C lto= dummy.rs 2>&1 | tee $(LOG) + grep 'codegen option `lto` takes no value' $(LOG) + $(RUSTC) -C lto=1 dummy.rs 2>&1 | tee $(LOG) + grep 'codegen option `lto` takes no value' $(LOG) + $(RUSTC) -C lto=foo dummy.rs 2>&1 | tee $(LOG) + grep 'codegen option `lto` takes no value' $(LOG) $(RUSTC) -C lto dummy.rs # Should not link dead code... diff --git a/src/test/run-make/llvm-phase/test.rs b/src/test/run-make/llvm-phase/test.rs index 7a63871f19e..2ff4593a801 100644 --- a/src/test/run-make/llvm-phase/test.rs +++ b/src/test/run-make/llvm-phase/test.rs @@ -77,6 +77,7 @@ fn main() { .split(' ').map(|s| s.to_string()).collect(); args.push("--out-dir".to_string()); args.push(env::var("TMPDIR").unwrap()); + args.push("-Ccodegen-units=1".to_string()); let (result, _) = rustc_driver::run_compiler( &args, &mut JitCalls, Some(box JitLoader), None); |