rustbuild: Remove ThinLTO-related configuration

src/bootstrap/bin/rustc.rs

@@ -175,9 +175,6 @@ fn main() {
         if let Ok(s) = env::var("RUSTC_CODEGEN_UNITS") {
             cmd.arg("-C").arg(format!("codegen-units={}", s));
         }
-        if env::var("RUSTC_THINLTO").is_ok() {
-            cmd.arg("-Ccodegen-units=16").arg("-Zthinlto");
-        }
 
         // Emit save-analysis info.
         if env::var("RUSTC_SAVE_ANALYSIS") == Ok("api".to_string()) {

src/bootstrap/builder.rs

@@ -792,17 +792,6 @@ impl<'a> Builder<'a> {
             if cmd != "bench" {
                 cargo.arg("--release");
             }
-
-            if self.config.rust_codegen_units.is_none() &&
-               self.build.is_rust_llvm(compiler.host) &&
-               self.config.rust_thinlto {
-                cargo.env("RUSTC_THINLTO", "1");
-            } else if self.config.rust_codegen_units.is_none() {
-                // Generally, if ThinLTO has been disabled for some reason, we
-                // want to set the codegen units to 1. However, we shouldn't do
-                // this if the option was specifically set by the user.
-                cargo.env("RUSTC_CODEGEN_UNITS", "1");
-            }
         }
 
         if self.config.locked_deps {

src/bootstrap/config.rs

@@ -86,7 +86,6 @@ pub struct Config {
     // rust codegen options
     pub rust_optimize: bool,
     pub rust_codegen_units: Option<u32>,
-    pub rust_thinlto: bool,
     pub rust_debug_assertions: bool,
     pub rust_debuginfo: bool,
     pub rust_debuginfo_lines: bool,
@@ -269,7 +268,6 @@ impl Default for StringOrBool {
 struct Rust {
     optimize: Option<bool>,
     codegen_units: Option<u32>,
-    thinlto: Option<bool>,
     debug_assertions: Option<bool>,
     debuginfo: Option<bool>,
     debuginfo_lines: Option<bool>,
@@ -427,7 +425,6 @@ impl Config {
 
         // Store off these values as options because if they're not provided
         // we'll infer default values for them later
-        let mut thinlto = None;
         let mut llvm_assertions = None;
         let mut debuginfo_lines = None;
         let mut debuginfo_only_std = None;
@@ -471,7 +468,6 @@ impl Config {
             optimize = rust.optimize;
             ignore_git = rust.ignore_git;
             debug_jemalloc = rust.debug_jemalloc;
-            thinlto = rust.thinlto;
             set(&mut config.rust_optimize_tests, rust.optimize_tests);
             set(&mut config.rust_debuginfo_tests, rust.debuginfo_tests);
             set(&mut config.codegen_tests, rust.codegen_tests);
@@ -559,7 +555,6 @@ impl Config {
             "stable" | "beta" | "nightly" => true,
             _ => false,
         };
-        config.rust_thinlto = thinlto.unwrap_or(true);
         config.rust_debuginfo_lines = debuginfo_lines.unwrap_or(default);
         config.rust_debuginfo_only_std = debuginfo_only_std.unwrap_or(default);
 

src/bootstrap/configure.py

@@ -71,7 +71,6 @@ def v(*args):
 # Optimization and debugging options. These may be overridden by the release
 # channel, etc.
 o("optimize", "rust.optimize", "build optimized rust code")
-o("thinlto", "rust.thinlto", "build Rust with ThinLTO enabled")
 o("optimize-llvm", "llvm.optimize", "build optimized LLVM")
 o("llvm-assertions", "llvm.assertions", "build LLVM with assertions")
 o("debug-assertions", "rust.debug-assertions", "build with debugging assertions")

src/ci/run.sh

@@ -46,7 +46,6 @@ export RUST_RELEASE_CHANNEL=nightly
 if [ "$DEPLOY$DEPLOY_ALT" != "" ]; then
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --release-channel=$RUST_RELEASE_CHANNEL"
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-llvm-static-stdcpp"
-  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-thinlto"
 
   if [ "$NO_LLVM_ASSERTIONS" = "1" ]; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-llvm-assertions"