diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index a4919b25fe3..34acb4ea10f 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -18,7 +18,7 @@ use rustc_feature::UnstableFeatures; use rustc_span::edition::{Edition, DEFAULT_EDITION, EDITION_NAME_LIST, LATEST_STABLE_EDITION}; use rustc_span::source_map::FilePathMapping; use rustc_span::{FileName, FileNameDisplayPreference, RealFileName, SourceFileHashAlgorithm}; -use rustc_target::spec::LinkSelfContainedComponents; +use rustc_target::spec::{LinkSelfContainedComponents, LinkerFeatures}; use rustc_target::spec::{SplitDebuginfo, Target, TargetTriple}; use std::collections::btree_map::{ Iter as BTreeMapIter, Keys as BTreeMapKeysIter, Values as BTreeMapValuesIter, @@ -292,6 +292,48 @@ impl LinkSelfContained { } } +/// The different values that `-Z linker-features` can take on the CLI: a list of individually +/// enabled or disabled features used during linking. +/// +/// There is no need to enable or disable them in bulk. Each feature is fine-grained, and can be +/// used to turn `LinkerFeatures` on or off, without needing to change the linker flavor: +/// - using the system lld, or the self-contained `rust-lld` linker +/// - using a C/C++ compiler to drive the linker (not yet exposed on the CLI) +/// - etc. +#[derive(Default, Copy, Clone, PartialEq, Debug)] +pub struct LinkerFeaturesCli { + /// The linker features that are enabled on the CLI, using the `+feature` syntax. + pub enabled: LinkerFeatures, + + /// The linker features that are disabled on the CLI, using the `-feature` syntax. + pub disabled: LinkerFeatures, +} + +impl LinkerFeaturesCli { + /// Accumulates an enabled or disabled feature as specified on the CLI, if possible. + /// For example: `+lld`, and `-lld`. + pub(crate) fn handle_cli_feature(&mut self, feature: &str) -> Option<()> { + // Duplicate flags are reduced as we go, the last occurrence wins: + // `+feature,-feature,+feature` only enables the feature, and does not record it as both + // enabled and disabled on the CLI. + // We also only expose `+/-lld` at the moment, as it's currenty the only implemented linker + // feature and toggling `LinkerFeatures::CC` would be a noop. + match feature { + "+lld" => { + self.enabled.insert(LinkerFeatures::LLD); + self.disabled.remove(LinkerFeatures::LLD); + Some(()) + } + "-lld" => { + self.disabled.insert(LinkerFeatures::LLD); + self.enabled.remove(LinkerFeatures::LLD); + Some(()) + } + _ => None, + } + } +} + /// Used with `-Z assert-incr-state`. #[derive(Clone, Copy, PartialEq, Hash, Debug)] pub enum IncrementalStateAssertion { diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index 5e7c2465097..963c9558c17 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -426,6 +426,8 @@ mod desc { "one of supported split dwarf modes (`split` or `single`)"; pub const parse_link_self_contained: &str = "one of: `y`, `yes`, `on`, `n`, `no`, `off`, or a list of enabled (`+` prefix) and disabled (`-` prefix) \ components: `crto`, `libc`, `unwind`, `linker`, `sanitizers`, `mingw`"; + pub const parse_linker_features: &str = + "a list of enabled (`+` prefix) and disabled (`-` prefix) features: `lld`"; pub const parse_polonius: &str = "either no value or `legacy` (the default), or `next`"; pub const parse_stack_protector: &str = "one of (`none` (default), `basic`, `strong`, or `all`)"; @@ -1269,6 +1271,22 @@ mod parse { true } + /// Parse a comma-separated list of enabled and disabled linker features. + pub(crate) fn parse_linker_features(slot: &mut LinkerFeaturesCli, v: Option<&str>) -> bool { + match v { + Some(s) => { + for feature in s.split(',') { + if slot.handle_cli_feature(feature).is_none() { + return false; + } + } + + true + } + None => false, + } + } + pub(crate) fn parse_wasi_exec_model(slot: &mut Option, v: Option<&str>) -> bool { match v { Some("command") => *slot = Some(WasiExecModel::Command), @@ -1721,6 +1739,8 @@ options! { "link native libraries in the linker invocation (default: yes)"), link_only: bool = (false, parse_bool, [TRACKED], "link the `.rlink` file generated by `-Z no-link` (default: no)"), + linker_features: LinkerFeaturesCli = (LinkerFeaturesCli::default(), parse_linker_features, [UNTRACKED], + "a comma-separated list of linker features to enable (+) or disable (-): `lld`"), lint_mir: bool = (false, parse_bool, [UNTRACKED], "lint MIR before and after each transformation"), llvm_module_flag: Vec<(String, u32, String)> = (Vec::new(), parse_llvm_module_flag, [TRACKED],