Add the relocation_model to the cfg

This way is possible to write inline assembly code aware of it.

compiler/rustc_feature/src/active.rs

@@ -352,6 +352,8 @@ pub fn set(&self, features: &mut Features, span: Span) {
     (active, c_variadic, "1.34.0", Some(44930), None),
     /// Allows the use of `#[cfg(overflow_checks)` to check if integer overflow behaviour.
     (active, cfg_overflow_checks, "1.71.0", Some(111466), None),
+    /// Provides the relocation model information as cfg entry
+    (active, cfg_relocation_model, "CURRENT_RUSTC_VERSION", Some(114929), None),
     /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
     (active, cfg_sanitize, "1.41.0", Some(39699), None),
     /// Allows `cfg(target_abi = "...")`.

compiler/rustc_feature/src/builtin_attrs.rs

@@ -35,6 +35,7 @@ macro_rules! cfg_fn {
     (sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
     (sym::sanitize, sym::cfg_sanitize, cfg_fn!(cfg_sanitize)),
     (sym::version, sym::cfg_version, cfg_fn!(cfg_version)),
+    (sym::relocation_model, sym::cfg_relocation_model, cfg_fn!(cfg_relocation_model)),
 ];
 
 /// Find a gated cfg determined by the `pred`icate which is given the cfg's name.

compiler/rustc_session/src/config.rs

@@ -12,7 +12,7 @@
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stable_hasher::{StableOrd, ToStableHashKey};
 use rustc_target::abi::Align;
-use rustc_target::spec::{PanicStrategy, SanitizerSet, SplitDebuginfo};
+use rustc_target::spec::{PanicStrategy, RelocModel, SanitizerSet, SplitDebuginfo};
 use rustc_target::spec::{Target, TargetTriple, TargetWarnings, TARGETS};
 
 use crate::parse::{CrateCheckConfig, CrateConfig};
@@ -1193,6 +1193,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
     let os = &sess.target.os;
     let env = &sess.target.env;
     let abi = &sess.target.abi;
+    let relocation_model = sess.target.relocation_model.desc_symbol();
     let vendor = &sess.target.vendor;
     let min_atomic_width = sess.target.min_atomic_width();
     let max_atomic_width = sess.target.max_atomic_width();
@@ -1218,6 +1219,9 @@ fn default_configuration(sess: &Session) -> CrateConfig {
     ret.insert((sym::target_pointer_width, Some(Symbol::intern(&wordsz))));
     ret.insert((sym::target_env, Some(Symbol::intern(env))));
     ret.insert((sym::target_abi, Some(Symbol::intern(abi))));
+    if sess.is_nightly_build() {
+        ret.insert((sym::relocation_model, Some(relocation_model)));
+    }
     ret.insert((sym::target_vendor, Some(Symbol::intern(vendor))));
     if sess.target.has_thread_local {
         ret.insert((sym::target_thread_local, None));
@@ -1415,6 +1419,8 @@ pub fn fill_well_known(&mut self, current_target: &Target) {
             .into_iter()
             .map(|sanitizer| Symbol::intern(sanitizer.as_str().unwrap()));
 
+        let relocation_model_values = RelocModel::all();
+
         // Unknown possible values:
         //  - `feature`
         //  - `target_feature`
@@ -1453,6 +1459,10 @@ pub fn fill_well_known(&mut self, current_target: &Target) {
             .entry(sym::target_has_atomic_equal_alignment)
             .or_insert_with(no_values)
             .extend(atomic_values);
+        self.expecteds
+            .entry(sym::relocation_model)
+            .or_insert_with(empty_values)
+            .extend(relocation_model_values);
 
         // Target specific values
         {

compiler/rustc_span/src/symbol.rs

@@ -468,6 +468,7 @@
         cfg_hide,
         cfg_overflow_checks,
         cfg_panic,
+        cfg_relocation_model,
         cfg_sanitize,
         cfg_target_abi,
         cfg_target_compact,
@@ -661,6 +662,7 @@
         dyn_metadata,
         dyn_star,
         dyn_trait,
+        dynamic_no_pic: "dynamic-no-pic",
         e,
         edition_panic,
         effects,
@@ -1115,6 +1117,8 @@
         path,
         pattern_parentheses,
         phantom_data,
+        pic,
+        pie,
         pin,
         platform_intrinsics,
         plugin,
@@ -1223,6 +1227,7 @@
         register_tool,
         relaxed_adts,
         relaxed_struct_unsize,
+        relocation_model,
         rem,
         rem_assign,
         repr,
@@ -1243,6 +1248,8 @@
         rintf64,
         riscv_target_feature,
         rlib,
+        ropi,
+        ropi_rwpi: "ropi-rwpi",
         rotate_left,
         rotate_right,
         roundevenf32,
@@ -1354,6 +1361,7 @@
         rustdoc_missing_doc_code_examples,
         rustfmt,
         rvalue_static_promotion,
+        rwpi,
         s,
         safety,
         sanitize,

compiler/rustc_target/src/spec/mod.rs

@@ -42,7 +42,7 @@
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_fs_util::try_canonicalize;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::{kw, sym, Symbol};
 use serde_json::Value;
 use std::borrow::Cow;
 use std::collections::BTreeMap;
@@ -655,6 +655,43 @@ pub enum RelocModel {
     RopiRwpi,
 }
 
+impl RelocModel {
+    pub fn desc(&self) -> &str {
+        match *self {
+            RelocModel::Static => "static",
+            RelocModel::Pic => "pic",
+            RelocModel::Pie => "pie",
+            RelocModel::DynamicNoPic => "dynamic-no-pic",
+            RelocModel::Ropi => "ropi",
+            RelocModel::Rwpi => "rwpi",
+            RelocModel::RopiRwpi => "ropi-rwpi",
+        }
+    }
+    pub const fn desc_symbol(&self) -> Symbol {
+        match *self {
+            RelocModel::Static => kw::Static,
+            RelocModel::Pic => sym::pic,
+            RelocModel::Pie => sym::pie,
+            RelocModel::DynamicNoPic => sym::dynamic_no_pic,
+            RelocModel::Ropi => sym::ropi,
+            RelocModel::Rwpi => sym::rwpi,
+            RelocModel::RopiRwpi => sym::ropi_rwpi,
+        }
+    }
+
+    pub const fn all() -> [Symbol; 7] {
+        [
+            RelocModel::Static.desc_symbol(),
+            RelocModel::Pic.desc_symbol(),
+            RelocModel::Pie.desc_symbol(),
+            RelocModel::DynamicNoPic.desc_symbol(),
+            RelocModel::Ropi.desc_symbol(),
+            RelocModel::Rwpi.desc_symbol(),
+            RelocModel::RopiRwpi.desc_symbol(),
+        ]
+    }
+}
+
 impl FromStr for RelocModel {
     type Err = ();
 
@@ -674,16 +711,7 @@ fn from_str(s: &str) -> Result<RelocModel, ()> {
 
 impl ToJson for RelocModel {
     fn to_json(&self) -> Json {
-        match *self {
-            RelocModel::Static => "static",
-            RelocModel::Pic => "pic",
-            RelocModel::Pie => "pie",
-            RelocModel::DynamicNoPic => "dynamic-no-pic",
-            RelocModel::Ropi => "ropi",
-            RelocModel::Rwpi => "rwpi",
-            RelocModel::RopiRwpi => "ropi-rwpi",
-        }
-        .to_json()
+        self.desc().to_json()
     }
 }
 

tests/ui/abi/relocation_model_pic.rs

@@ -0,0 +1,9 @@
+// run-pass
+// compile-flags: -C relocation-model=pic
+// ignore-emscripten no pic
+// ignore-wasm
+
+#![feature(cfg_relocation_model)]
+
+#[cfg(relocation_model = "pic")]
+fn main() {}

tests/ui/feature-gates/feature-gate-cfg-relocation-model.rs

@@ -0,0 +1,4 @@
+#[cfg(relocation_model = "pic")] //~ ERROR
+fn _foo() {}
+
+fn main() {}

tests/ui/feature-gates/feature-gate-cfg-relocation-model.stderr

@@ -0,0 +1,12 @@
+error[E0658]: `cfg(relocation_model)` is experimental and subject to change
+  --> $DIR/feature-gate-cfg-relocation-model.rs:1:7
+   |
+LL | #[cfg(relocation_model = "pic")]
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #114929 <https://github.com/rust-lang/rust/issues/114929> for more information
+   = help: add `#![feature(cfg_relocation_model)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.