rustc_target: Stop using "string typing" for relocation models

Introduce `enum RelocModel` instead.

3 files changed, 21 insertions, 12 deletions

diff --git a/src/librustc_session/config.rs b/src/librustc_session/config.rs
index f6d7e091e00..1ab02f84c11 100644
--- a/src/librustc_session/config.rs
+++ b/src/librustc_session/config.rs
@@ -1311,10 +1311,6 @@ fn collect_print_requests(
         prints.push(PrintRequest::TargetFeatures);
         cg.target_feature = String::new();
     }
-    if cg.relocation_model.as_ref().map_or(false, |s| s == "help") {
-        prints.push(PrintRequest::RelocationModels);
-        cg.relocation_model = None;
-    }
     if cg.code_model.as_ref().map_or(false, |s| s == "help") {
         prints.push(PrintRequest::CodeModels);
         cg.code_model = None;
@@ -2005,7 +2001,7 @@ crate mod dep_tracking {
     use crate::utils::NativeLibraryKind;
     use rustc_feature::UnstableFeatures;
     use rustc_span::edition::Edition;
-    use rustc_target::spec::{MergeFunctions, PanicStrategy, RelroLevel, TargetTriple};
+    use rustc_target::spec::{MergeFunctions, PanicStrategy, RelocModel, RelroLevel, TargetTriple};
     use std::collections::hash_map::DefaultHasher;
     use std::collections::BTreeMap;
     use std::hash::Hash;
@@ -2053,6 +2049,7 @@ crate mod dep_tracking {
     impl_dep_tracking_hash_via_hash!(Option<(String, u64)>);
     impl_dep_tracking_hash_via_hash!(Option<Vec<String>>);
     impl_dep_tracking_hash_via_hash!(Option<MergeFunctions>);
+    impl_dep_tracking_hash_via_hash!(Option<RelocModel>);
     impl_dep_tracking_hash_via_hash!(Option<PanicStrategy>);
     impl_dep_tracking_hash_via_hash!(Option<RelroLevel>);
     impl_dep_tracking_hash_via_hash!(Option<lint::Level>);
diff --git a/src/librustc_session/options.rs b/src/librustc_session/options.rs
index 54b2f2fe470..804e929bc81 100644
--- a/src/librustc_session/options.rs
+++ b/src/librustc_session/options.rs
@@ -6,7 +6,7 @@ use crate::search_paths::SearchPath;
 use crate::utils::NativeLibraryKind;
 
 use rustc_target::spec::TargetTriple;
-use rustc_target::spec::{LinkerFlavor, MergeFunctions, PanicStrategy, RelroLevel};
+use rustc_target::spec::{LinkerFlavor, MergeFunctions, PanicStrategy, RelocModel, RelroLevel};
 
 use rustc_feature::UnstableFeatures;
 use rustc_span::edition::Edition;
@@ -265,14 +265,13 @@ macro_rules! options {
         pub const parse_merge_functions: &str = "one of: `disabled`, `trampolines`, or `aliases`";
         pub const parse_symbol_mangling_version: &str = "either `legacy` or `v0` (RFC 2603)";
         pub const parse_src_file_hash: &str = "either `md5` or `sha1`";
+        pub const parse_relocation_model: &str =
+            "one of supported relocation models (`rustc --print relocation-models`)";
     }
 
     #[allow(dead_code)]
     mod $mod_set {
-        use super::{$struct_name, Passes, Sanitizer, LtoCli, LinkerPluginLto, SwitchWithOptPath,
-            SymbolManglingVersion, CFGuard, SourceFileHashAlgorithm};
-        use rustc_target::spec::{LinkerFlavor, MergeFunctions, PanicStrategy, RelroLevel};
-        use std::path::PathBuf;
+        use super::*;
         use std::str::FromStr;
 
         // Sometimes different options need to build a common structure.
@@ -598,6 +597,15 @@ macro_rules! options {
             true
         }
 
+        fn parse_relocation_model(slot: &mut Option<RelocModel>, v: Option<&str>) -> bool {
+            match v.and_then(|s| RelocModel::from_str(s).ok()) {
+                Some(relocation_model) => *slot = Some(relocation_model),
+                None if v == Some("default") => *slot = None,
+                _ => return false,
+            }
+            true
+        }
+
         fn parse_symbol_mangling_version(
             slot: &mut SymbolManglingVersion,
             v: Option<&str>,
@@ -697,7 +705,7 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
         "compile the program with profiling instrumentation"),
     profile_use: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "use the given `.profdata` file for profile-guided optimization"),
-    relocation_model: Option<String> = (None, parse_opt_string, [TRACKED],
+    relocation_model: Option<RelocModel> = (None, parse_relocation_model, [TRACKED],
         "choose the relocation model to use (`rustc --print relocation-models` for details)"),
     remark: Passes = (Passes::Some(Vec::new()), parse_passes, [UNTRACKED],
         "print remarks for these optimization passes (space separated, or \"all\")"),
diff --git a/src/librustc_session/session.rs b/src/librustc_session/session.rs
index f0bbe1d0a18..226d9392095 100644
--- a/src/librustc_session/session.rs
+++ b/src/librustc_session/session.rs
@@ -22,7 +22,7 @@ use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticId, ErrorReported
 use rustc_span::edition::Edition;
 use rustc_span::source_map::{self, FileLoader, MultiSpan, RealFileLoader, SourceMap, Span};
 use rustc_span::SourceFileHashAlgorithm;
-use rustc_target::spec::{PanicStrategy, RelroLevel, Target, TargetTriple};
+use rustc_target::spec::{PanicStrategy, RelocModel, RelroLevel, Target, TargetTriple};
 
 use std::cell::{self, RefCell};
 use std::env;
@@ -584,6 +584,10 @@ impl Session {
         }
     }
 
+    pub fn relocation_model(&self) -> RelocModel {
+        self.opts.cg.relocation_model.unwrap_or(self.target.target.options.relocation_model)
+    }
+
     pub fn must_not_eliminate_frame_pointers(&self) -> bool {
         // "mcount" function relies on stack pointer.
         // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.