wip

Author: lqd

Cargo.lock

@@ -4391,7 +4391,6 @@ dependencies = [
 name = "rustc_session"
 version = "0.0.0"
 dependencies = [
- "bitflags 1.3.2",
  "getopts",
  "libc",
  "rustc_ast",

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -22,7 +22,8 @@ use rustc_session::utils::NativeLibKind;
 /// need out of the shared crate context before we get rid of it.
 use rustc_session::{filesearch, Session};
 use rustc_span::symbol::Symbol;
-use rustc_target::spec::crt_objects::{CrtObjects, LinkSelfContainedDefault};
+use rustc_target::spec::crt_objects::CrtObjects;
+use rustc_target::spec::LinkSelfContained;
 use rustc_target::spec::{Cc, LinkOutputKind, LinkerFlavor, Lld, PanicStrategy};
 use rustc_target::spec::{RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo};
 
@@ -1709,21 +1710,37 @@ fn detect_self_contained_mingw(sess: &Session) -> bool {
 /// instead of being found somewhere on the host system.
 /// We only provide such support for a very limited number of targets.
 fn self_contained(sess: &Session, crate_type: CrateType) -> bool {
+    // Emit an error if the user requested self-contained mode on the CLI but the target explicitly
+    // refuses it.
     if let Some(self_contained) = sess.opts.cg.link_self_contained.explicitly_set {
-        if sess.target.link_self_contained == LinkSelfContainedDefault::False {
+        if sess.target.link_self_contained.is_disabled() {
             sess.emit_err(errors::UnsupportedLinkSelfContained);
         }
         return self_contained;
     }
 
     match sess.target.link_self_contained {
-        LinkSelfContainedDefault::False => false,
-        LinkSelfContainedDefault::True => true,
+        LinkSelfContained::True => true,
+        LinkSelfContained::False => false,
+        LinkSelfContained::WithComponents(components) => {
+            if components.is_all() {
+                true
+            } else if components.is_empty() {
+                false
+            } else {
+                // FIXME: Currently no target makes use of individual components to mean
+                // self-contained linking is fully enabled, in the sense of what the code downstream
+                // from here expects. Until components are handled a bit more deeply, we can
+                // consider that it's disabled and remain backwards compatible.
+                false
+            }
+        }
+
         // FIXME: Find a better heuristic for "native musl toolchain is available",
         // based on host and linker path, for example.
         // (https://github.com/rust-lang/rust/pull/71769#issuecomment-626330237).
-        LinkSelfContainedDefault::Musl => sess.crt_static(Some(crate_type)),
-        LinkSelfContainedDefault::Mingw => {
+        LinkSelfContained::InferredForMusl => sess.crt_static(Some(crate_type)),
+        LinkSelfContained::InferredForMingw => {
             sess.host == sess.target
                 && sess.target.vendor != "uwp"
                 && detect_self_contained_mingw(&sess)
@@ -2992,9 +3009,15 @@ fn add_lld_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
     }
 
     // 1. Implement the "self-contained" part of this feature by adding rustc distribution
-    //    directories to the tool's search path.
-    let self_contained_linker = sess.opts.cg.link_self_contained.linker() || unstable_use_lld;
-    if self_contained_linker {
+    // directories to the tool's search path, depending on a mix between what users can specify on
+    // the CLI, and what the target spec enables (as it can't disable components):
+    // - if the self-contained linker is enabled on the CLI or by the target spec (or by the
+    //   unstable CLI flag that will be removed eventually),
+    // - and if the self-contained linker is not disabled on the CLI.
+    let self_contained_linker = sess.target.options.link_self_contained.is_linker_enabled()
+        || sess.opts.cg.link_self_contained.is_linker_enabled()
+        || unstable_use_lld;
+    if self_contained_linker && !sess.opts.cg.link_self_contained.is_linker_disabled() {
         for path in sess.get_tools_search_paths(false) {
             cmd.arg({
                 let mut arg = OsString::from("-B");
@@ -3005,7 +3028,7 @@ fn add_lld_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
     }
 
     // 2. Implement the "linker flavor" part of this feature by asking `cc` to use some kind of
-    //    `lld` as the linker.
+    // `lld` as the linker.
     cmd.arg("-fuse-ld=lld");
 
     if !flavor.is_gnu() {

compiler/rustc_session/Cargo.toml

@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
-bitflags = "1.2.1"
 getopts = "0.2"
 rustc_macros = { path = "../rustc_macros" }
 tracing = "0.1"

compiler/rustc_session/src/config.rs

@@ -12,6 +12,7 @@ use crate::{EarlyErrorHandler, Session};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stable_hasher::{StableOrd, ToStableHashKey};
 use rustc_target::abi::Align;
+use rustc_target::spec::LinkSelfContainedComponents;
 use rustc_target::spec::{PanicStrategy, RelocModel, SanitizerSet, SplitDebuginfo};
 use rustc_target::spec::{Target, TargetTriple, TargetWarnings, TARGETS};
 
@@ -232,75 +233,50 @@ pub struct LinkSelfContained {
     /// Used for compatibility with the existing opt-in and target inference.
     pub explicitly_set: Option<bool>,
 
-    /// The components that are enabled.
-    components: LinkSelfContainedComponents,
-}
+    /// The components that are enabled on the CLI, using the `+component` syntax or one of the
+    /// `true` shorcuts.
+    enabled_components: LinkSelfContainedComponents,
 
-bitflags::bitflags! {
-    #[derive(Default)]
-    /// The `-C link-self-contained` components that can individually be enabled or disabled.
-    pub struct LinkSelfContainedComponents: u8 {
-        /// CRT objects (e.g. on `windows-gnu`, `musl`, `wasi` targets)
-        const CRT_OBJECTS = 1 << 0;
-        /// libc static library (e.g. on `musl`, `wasi` targets)
-        const LIBC        = 1 << 1;
-        /// libgcc/libunwind (e.g. on `windows-gnu`, `fuchsia`, `fortanix`, `gnullvm` targets)
-        const UNWIND      = 1 << 2;
-        /// Linker, dlltool, and their necessary libraries (e.g. on `windows-gnu` and for `rust-lld`)
-        const LINKER      = 1 << 3;
-        /// Sanitizer runtime libraries
-        const SANITIZERS  = 1 << 4;
-        /// Other MinGW libs and Windows import libs
-        const MINGW       = 1 << 5;
-    }
-}
-
-impl FromStr for LinkSelfContainedComponents {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(match s {
-            "crto" => LinkSelfContainedComponents::CRT_OBJECTS,
-            "libc" => LinkSelfContainedComponents::LIBC,
-            "unwind" => LinkSelfContainedComponents::UNWIND,
-            "linker" => LinkSelfContainedComponents::LINKER,
-            "sanitizers" => LinkSelfContainedComponents::SANITIZERS,
-            "mingw" => LinkSelfContainedComponents::MINGW,
-            _ => return Err(()),
-        })
-    }
+    /// The components that are disabled on the CLI, using the `-component` syntax or one of the
+    /// `false` shortcuts.
+    disabled_components: LinkSelfContainedComponents,
 }
 
 impl LinkSelfContained {
     /// Incorporates an enabled or disabled component as specified on the CLI, if possible.
     /// For example: `+linker`, and `-crto`.
-    pub(crate) fn handle_cli_component(&mut self, component: &str) -> Result<(), ()> {
+    pub(crate) fn handle_cli_component(&mut self, component: &str) -> Option<()> {
         // Note that for example `-Cself-contained=y -Cself-contained=-linker` is not an explicit
         // set of all values like `y` or `n` used to be. Therefore, if this flag had previously been
         // set in bulk with its historical values, then manually setting a component clears that
         // `explicitly_set` state.
         if let Some(component_to_enable) = component.strip_prefix('+') {
             self.explicitly_set = None;
-            self.components.insert(component_to_enable.parse()?);
-            Ok(())
+            self.enabled_components
+                .insert(LinkSelfContainedComponents::from_str(component_to_enable)?);
+            Some(())
         } else if let Some(component_to_disable) = component.strip_prefix('-') {
             self.explicitly_set = None;
-            self.components.remove(component_to_disable.parse()?);
-            Ok(())
+            self.disabled_components
+                .insert(LinkSelfContainedComponents::from_str(component_to_disable)?);
+            Some(())
         } else {
-            Err(())
+            None
         }
     }
 
     /// Turns all components on or off and records that this was done explicitly for compatibility
     /// purposes.
     pub(crate) fn set_all_explicitly(&mut self, enabled: bool) {
         self.explicitly_set = Some(enabled);
-        self.components = if enabled {
-            LinkSelfContainedComponents::all()
+
+        if enabled {
+            self.enabled_components = LinkSelfContainedComponents::all();
+            self.disabled_components = LinkSelfContainedComponents::empty();
         } else {
-            LinkSelfContainedComponents::empty()
-        };
+            self.enabled_components = LinkSelfContainedComponents::empty();
+            self.disabled_components = LinkSelfContainedComponents::all();
+        }
     }
 
     /// Helper creating a fully enabled `LinkSelfContained` instance. Used in tests.
@@ -314,13 +290,21 @@ impl LinkSelfContained {
     /// components was set individually. This would also require the `-Zunstable-options` flag, to
     /// be allowed.
     fn are_unstable_variants_set(&self) -> bool {
-        let any_component_set = !self.components.is_empty();
+        let any_component_set =
+            !self.enabled_components.is_empty() || !self.disabled_components.is_empty();
         self.explicitly_set.is_none() && any_component_set
     }
 
-    /// Returns whether the self-contained linker component is enabled.
-    pub fn linker(&self) -> bool {
-        self.components.contains(LinkSelfContainedComponents::LINKER)
+    /// Returns whether the self-contained linker component was enabled on the CLI, using the
+    /// `-C link-self-contained=+linker` syntax, or one of the `true` shorcuts.
+    pub fn is_linker_enabled(&self) -> bool {
+        self.enabled_components.contains(LinkSelfContainedComponents::LINKER)
+    }
+
+    /// Returns whether the self-contained linker component was disabled on the CLI, using the
+    /// `-C link-self-contained=-linker` syntax, or one of the `false` shorcuts.
+    pub fn is_linker_disabled(&self) -> bool {
+        self.disabled_components.contains(LinkSelfContainedComponents::LINKER)
     }
 }
 

compiler/rustc_session/src/options.rs

@@ -1160,7 +1160,7 @@ mod parse {
 
         // 2. Parse a list of enabled and disabled components.
         for comp in s.split(',') {
-            if slot.handle_cli_component(comp).is_err() {
+            if slot.handle_cli_component(comp).is_none() {
                 return false;
             }
         }

compiler/rustc_target/src/spec/crt_objects.rs

@@ -40,7 +40,6 @@
 //! but not gcc's. As a result rustc cannot link with C++ static libraries (#36710)
 //! when linking in self-contained mode.
 
-use crate::json::{Json, ToJson};
 use crate::spec::LinkOutputKind;
 use std::borrow::Cow;
 use std::collections::BTreeMap;
@@ -147,15 +146,3 @@ impl FromStr for LinkSelfContainedDefault {
         })
     }
 }
-
-impl ToJson for LinkSelfContainedDefault {
-    fn to_json(&self) -> Json {
-        match *self {
-            LinkSelfContainedDefault::False => "false",
-            LinkSelfContainedDefault::True => "true",
-            LinkSelfContainedDefault::Musl => "musl",
-            LinkSelfContainedDefault::Mingw => "mingw",
-        }
-        .to_json()
-    }
-}

compiler/rustc_target/src/spec/linux_musl_base.rs

@@ -1,4 +1,5 @@
-use crate::spec::crt_objects::{self, LinkSelfContainedDefault};
+use crate::spec::crt_objects;
+use crate::spec::LinkSelfContained;
 use crate::spec::TargetOptions;
 
 pub fn opts() -> TargetOptions {
@@ -7,7 +8,7 @@ pub fn opts() -> TargetOptions {
     base.env = "musl".into();
     base.pre_link_objects_self_contained = crt_objects::pre_musl_self_contained();
     base.post_link_objects_self_contained = crt_objects::post_musl_self_contained();
-    base.link_self_contained = LinkSelfContainedDefault::Musl;
+    base.link_self_contained = LinkSelfContained::InferredForMusl;
 
     // These targets statically link libc by default
     base.crt_static_default = true;