Add "system" option to override-allocator directive

INSTALL.md

@@ -96,7 +96,7 @@ See [the rustc-dev-guide for more info][sysllvm].
       --set llvm.libzstd=true \
       --set llvm.ninja=false \
       --set rust.debug-assertions=false \
-      --set rust.override-allocator=jemalloc \
+      --set build.allocator=jemalloc \
       --set rust.bootstrap-override-lld=true \
       --set rust.lto=thin \
       --set rust.codegen-units=1

bootstrap.example.toml

@@ -544,6 +544,12 @@
 # For example, exclude = ["tests/ui", "src/tools/tidy"].
 #build.exclude = []
 
+# Link the compiler and LLVM against the specified allocator instead of the default libc allocator.
+# This option is only tested on Linux and OSX. It can also be configured per-target in the
+# [target.<tuple>] section.
+# Possible options: "system" (default), "jemalloc"
+#build.allocator = "jemalloc"
+
 # =============================================================================
 # General install configuration options
 # =============================================================================
@@ -859,15 +865,9 @@
 # Useful for reproducible builds. Generally only set for releases
 #rust.remap-debuginfo = false
 
-# Link the compiler and LLVM against the specified allocator instead of the default libc allocator.
-# This option is only tested on Linux and OSX. It can also be configured per-target in the
-# [target.<tuple>] section.
-# Possible options: "jemalloc"
-#rust.override-allocator = "jemalloc"
-
-# Deprecated alias for `rust.override-allocator`. Setting this to `true` is
-# equivalent to `rust.override-allocator = "jemalloc"`. If both are set, they
-# must agree.
+# Deprecated alias for `build.allocator`. Setting this to `true` is
+# equivalent to `build.allocator = "jemalloc"`. Both cannot be set in the same section
+# (`rust` or `target.[target]`)
 #rust.jemalloc = false
 
 # Run tests in various test suites with the "nll compare mode" in addition to
@@ -1177,10 +1177,10 @@
 #optimized-compiler-builtins = build.optimized-compiler-builtins (bool or path)
 
 # Link the compiler and LLVM against the specified allocator instead of the default libc allocator.
-# This overrides the global `rust.override-allocator` option. See that option for more info.
-#override-allocator = rust.override-allocator (string)
+# This overrides the global `build.allocator` option. See that option for more info.
+#allocator = build.allocator (string)
 
-# Deprecated alias for `override-allocator`. See `rust.jemalloc` for more info.
+# Deprecated alias for `allocator`. See `rust.jemalloc` for more info.
 #jemalloc = rust.jemalloc (bool)
 
 # The linker configuration that will *override* the default linker used for Linux

src/bootstrap/download-ci-llvm-stamp

@@ -1,4 +1,4 @@
 Change this file to make users of the `download-ci-llvm` configuration download
 a new version of LLVM from CI, even if the LLVM submodule hasn’t changed.
 
-Last change is for: https://github.com/rust-lang/rust/pull/158766
+Last change is for: https://github.com/rust-lang/rust/pull/160100

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

@@ -28,7 +28,7 @@ use crate::core::builder::{
 };
 use crate::core::config::toml::target::DefaultLinuxLinkerOverride;
 use crate::core::config::{
-    CompilerBuiltins, DebuginfoLevel, LlvmLibunwind, OverrideAllocator, RustcLto, TargetSelection,
+    Allocator, CompilerBuiltins, DebuginfoLevel, LlvmLibunwind, RustcLto, TargetSelection,
 };
 use crate::utils::build_stamp;
 use crate::utils::build_stamp::BuildStamp;
@@ -1392,7 +1392,7 @@ pub fn rustc_cargo_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetS
     }
 
     // See also the "JEMALLOC_SYS_WITH_LG_PAGE" setting in the tool build step.
-    if let Some(OverrideAllocator::Jemalloc) = builder.config.override_allocator(target)
+    if builder.config.allocator(target) == Allocator::Jemalloc
         && env::var_os("JEMALLOC_SYS_WITH_LG_PAGE").is_none()
     {
         // Build jemalloc on AArch64 with support for page sizes up to 64K

src/bootstrap/src/core/build_steps/tool.rs

@@ -21,7 +21,7 @@ use crate::core::builder::{
     Builder, Cargo as CargoCommand, CommandLineStep, RunConfig, ShouldRun, Step, StepMetadata,
     apply_pgo, cargo_profile_var,
 };
-use crate::core::config::{DebuginfoLevel, OverrideAllocator, RustcLto, TargetSelection};
+use crate::core::config::{Allocator, DebuginfoLevel, RustcLto, TargetSelection};
 use crate::utils::exec::{BootstrapCommand, command};
 use crate::utils::helpers::{add_dylib_path, exe, t};
 use crate::{Compiler, FileType, Kind, Mode};
@@ -241,7 +241,7 @@ pub fn prepare_tool_cargo(
     cargo.env("LZMA_API_STATIC", "1");
 
     // See also the "JEMALLOC_SYS_WITH_LG_PAGE" setting in the compile build step.
-    if let Some(OverrideAllocator::Jemalloc) = builder.config.override_allocator(target)
+    if builder.config.allocator(target) == Allocator::Jemalloc
         && env::var_os("JEMALLOC_SYS_WITH_LG_PAGE").is_none()
     {
         // Build jemalloc on AArch64 with support for page sizes up to 64K
@@ -767,8 +767,8 @@ impl CommandLineStep for Rustdoc {
         // to build rustdoc.
         //
         let mut extra_features = Vec::new();
-        if let Some(allocator) = builder.config.override_allocator(target) {
-            extra_features.push(allocator.feature_name().to_string());
+        if let Some(allocator_feature_name) = builder.config.allocator(target).feature_name() {
+            extra_features.push(allocator_feature_name.to_string());
         }
         if !builder.config.rust_debug_logging {
             extra_features.push("max_level_info".to_string())
@@ -1585,8 +1585,8 @@ tool_rustc_extended!(Clippy {
     stable: true,
     add_bins_to_sysroot: ["clippy-driver"],
     add_features: |builder, target, features| {
-        if let Some(allocator) = builder.config.override_allocator(target) {
-            features.push(allocator.feature_name().to_string());
+        if let Some(allocator_feature_name) = builder.config.allocator(target).feature_name() {
+            features.push(allocator_feature_name.to_string());
         }
     }
 });
@@ -1596,8 +1596,8 @@ tool_rustc_extended!(Miri {
     stable: false,
     add_bins_to_sysroot: ["miri"],
     add_features: |builder, target, features| {
-        if let Some(allocator) = builder.config.override_allocator(target) {
-            features.push(allocator.feature_name().to_string());
+        if let Some(allocator_feature_name) = builder.config.allocator(target).feature_name() {
+            features.push(allocator_feature_name.to_string());
         }
     },
     // Always compile also tests when building miri. Otherwise feature unification can cause rebuilds between building and testing miri.

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

@@ -49,8 +49,8 @@ use crate::core::config::toml::target::{
     DefaultLinuxLinkerOverride, Target, TomlTarget, default_linux_linker_overrides,
 };
 use crate::core::config::{
-    CompilerBuiltins, CompressDebuginfo, DebuggerPath, DebuginfoLevel, DryRun, GccCiMode,
-    LlvmLibunwind, Merge, OverrideAllocator, ReplaceOpt, RustcLto, SplitDebuginfo, StringOrBool,
+    Allocator, CompilerBuiltins, CompressDebuginfo, DebuggerPath, DebuginfoLevel, DryRun,
+    GccCiMode, LlvmLibunwind, Merge, ReplaceOpt, RustcLto, SplitDebuginfo, StringOrBool,
     threads_from_config,
 };
 use crate::core::download::{
@@ -249,7 +249,7 @@ pub struct Config {
     pub hosts: Vec<TargetSelection>,
     pub targets: Vec<TargetSelection>,
     pub local_rebuild: bool,
-    pub override_allocator: Option<OverrideAllocator>,
+    pub allocator: Option<Allocator>,
     pub control_flow_guard: bool,
     pub ehcont_guard: bool,
 
@@ -538,6 +538,7 @@ impl Config {
             exclude: build_exclude,
             compiletest_allow_stage0: build_compiletest_allow_stage0,
             sde: build_sde,
+            allocator: build_allocator,
         } = toml_build.unwrap_or_default();
 
         let Install {
@@ -590,7 +591,6 @@ impl Config {
             thin_lto_import_instr_limit: rust_thin_lto_import_instr_limit,
             parallel_frontend_threads: rust_parallel_frontend_threads,
             remap_debuginfo: rust_remap_debuginfo,
-            override_allocator: rust_override_allocator,
             jemalloc: rust_jemalloc,
             test_compare_mode: rust_test_compare_mode,
             llvm_libunwind: rust_llvm_libunwind,
@@ -970,7 +970,7 @@ impl Config {
                     codegen_backends: target_codegen_backends,
                     runner: target_runner,
                     optimized_compiler_builtins: target_optimized_compiler_builtins,
-                    override_allocator: target_override_allocator,
+                    allocator: target_allocator,
                     jemalloc: target_jemalloc,
                 } = cfg;
 
@@ -1047,9 +1047,10 @@ impl Config {
                 target.rpath = target_rpath;
                 target.rustflags = target_rustflags.unwrap_or_default();
                 target.optimized_compiler_builtins = target_optimized_compiler_builtins;
-                target.override_allocator = reconcile_jemalloc(
+                target.allocator = reconcile_jemalloc(
                     target_jemalloc,
-                    target_override_allocator,
+                    target_allocator,
+                    &format!("target.{triple}"),
                     &format!("target.{triple}"),
                 );
                 if let Some(backends) = target_codegen_backends {
@@ -1396,6 +1397,7 @@ NOTE: Please add `--stage 2` to your command line, or if you're sure you want to
 
         Config {
             // tidy-alphabetical-start
+            allocator: reconcile_jemalloc(rust_jemalloc, build_allocator, "rust", "build"),
             android_ndk: build_android_ndk,
             backtrace: rust_backtrace.unwrap_or(true),
             backtrace_on_ice: rust_backtrace_on_ice.unwrap_or(false),
@@ -1521,7 +1523,6 @@ NOTE: Please add `--stage 2` to your command line, or if you're sure you want to
             on_fail: flags_on_fail,
             optimized_compiler_builtins,
             out,
-            override_allocator: reconcile_jemalloc(rust_jemalloc, rust_override_allocator, "rust"),
             patch_binaries_for_nix: build_patch_binaries_for_nix,
             path_modification_cache,
             paths,
@@ -1956,11 +1957,12 @@ NOTE: Please add `--stage 2` to your command line, or if you're sure you want to
         self.enabled_codegen_backends(target).first().unwrap()
     }
 
-    pub fn override_allocator(&self, target: TargetSelection) -> Option<OverrideAllocator> {
+    pub fn allocator(&self, target: TargetSelection) -> Allocator {
         self.target_config
             .get(&target)
-            .and_then(|cfg| cfg.override_allocator)
-            .or(self.override_allocator)
+            .and_then(|cfg| cfg.allocator)
+            .or(self.allocator)
+            .unwrap_or(Allocator::System)
     }
 
     pub fn rpath_enabled(&self, target: TargetSelection) -> bool {
@@ -2054,35 +2056,39 @@ impl AsRef<ExecutionContext> for Config {
 }
 
 /// Reconciles the deprecated `jemalloc` boolean option with the new
-/// `override-allocator` option.
+/// `allocator` option.
 ///
-/// Emits a warning if `jemalloc` is present and errors out if it is set but
-/// `override-allocator` is not `jemalloc`. The allocator is overridden if
-/// either option is set.
+/// Emits a warning if `jemalloc` is set, and an error if *both* `jemalloc` and `allocator` are set.
 fn reconcile_jemalloc(
     jemalloc: Option<bool>,
-    override_allocator: Option<OverrideAllocator>,
-    section: &str,
-) -> Option<OverrideAllocator> {
-    if let Some(jemalloc) = jemalloc {
-        println!(
-            "WARNING: The `{section}.jemalloc` option is deprecated. \
-             Use `{section}.override-allocator` instead.",
-        );
-        if jemalloc && override_allocator.is_some_and(|a| a != OverrideAllocator::Jemalloc) {
-            panic!(
-                "ERROR: `{section}.jemalloc` is set but `{section}.override-allocator` is \
-                 not `jemalloc` ({:?}). Remove the deprecated `jemalloc` option or set \
-                 `override-allocator = \"jemalloc\"`.",
-                override_allocator,
+    allocator: Option<Allocator>,
+    jemalloc_section: &str,
+    allocator_section: &str,
+) -> Option<Allocator> {
+    match (jemalloc, allocator) {
+        (None, None) => None,
+        (None, Some(allocator)) => Some(allocator),
+        (Some(true), None) => {
+            println!(
+                "WARNING: The `jemalloc` option is deprecated. \
+                 Please use `{allocator_section}.allocator = \"jemalloc\"` instead of `{jemalloc_section}.jemalloc = true`",
+            );
+            Some(Allocator::Jemalloc)
+        }
+        (Some(false), None) => {
+            println!(
+                "WARNING: The `jemalloc` option is deprecated. \
+                 Please use `{allocator_section}.allocator = \"system\"` instead of `{jemalloc_section}.jemalloc = false`",
             );
+            Some(Allocator::System)
+        }
+        _ => {
+            panic!(
+                "ERROR: `{jemalloc_section}.jemalloc` and `{allocator_section}.allocator` are both set. \
+                 Please remove the outdated `{jemalloc_section}.jemalloc` directive."
+            )
         }
     }
-    override_allocator.or(if jemalloc == Some(true) {
-        Some(OverrideAllocator::Jemalloc)
-    } else {
-        None
-    })
 }
 
 fn compute_src_directory(src_dir: Option<PathBuf>, exec_ctx: &ExecutionContext) -> Option<PathBuf> {

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

@@ -252,27 +252,30 @@ impl<'de> Deserialize<'de> for CompilerBuiltins {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub enum OverrideAllocator {
+pub enum Allocator {
+    System,
     Jemalloc,
 }
 
-impl OverrideAllocator {
-    pub fn feature_name(self) -> &'static str {
+impl Allocator {
+    pub fn feature_name(self) -> Option<&'static str> {
         match self {
-            OverrideAllocator::Jemalloc => "jemalloc",
+            Allocator::System => None,
+            Allocator::Jemalloc => Some("jemalloc"),
         }
     }
 }
 
-impl<'de> Deserialize<'de> for OverrideAllocator {
+impl<'de> Deserialize<'de> for Allocator {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>,
     {
         let name = String::deserialize(deserializer)?;
         match name.as_str() {
+            "system" => Ok(Self::System),
             "jemalloc" => Ok(Self::Jemalloc),
-            other => Err(serde::de::Error::unknown_variant(other, &["jemalloc"])),
+            other => Err(serde::de::Error::unknown_variant(other, &["system", "jemalloc"])),
         }
     }
 }

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

@@ -11,7 +11,7 @@ use std::collections::HashMap;
 use serde::{Deserialize, Deserializer};
 
 use crate::core::config::toml::ReplaceOpt;
-use crate::core::config::{CompilerBuiltins, DebuggerPath, Merge, StringOrBool};
+use crate::core::config::{Allocator, CompilerBuiltins, DebuggerPath, Merge, StringOrBool};
 use crate::{HashSet, PathBuf, define_config, exit};
 
 define_config! {
@@ -77,6 +77,7 @@ define_config! {
         exclude: Option<Vec<PathBuf>> = "exclude",
         record_failed_tests_path: Option<String> = "record_failed_tests_path",
         sde: Option<String> = "sde",
+        allocator: Option<Allocator> = "allocator",
     }
 }