rustc_target: Stop using "string typing" for TLS models

Introduce `enum TlsModel` instead.

3 files changed, 9 insertions, 23 deletions

diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs
index bf79c5b593e..3ec7ef831b5 100644
--- a/src/librustc_codegen_llvm/back/write.rs
+++ b/src/librustc_codegen_llvm/back/write.rs
@@ -43,13 +43,6 @@ pub const CODE_GEN_MODEL_ARGS: &[(&str, llvm::CodeModel)] = &[
     ("large", llvm::CodeModel::Large),
 ];
 
-pub const TLS_MODEL_ARGS: [(&str, llvm::ThreadLocalMode); 4] = [
-    ("global-dynamic", llvm::ThreadLocalMode::GeneralDynamic),
-    ("local-dynamic", llvm::ThreadLocalMode::LocalDynamic),
-    ("initial-exec", llvm::ThreadLocalMode::InitialExec),
-    ("local-exec", llvm::ThreadLocalMode::LocalExec),
-];
-
 pub fn llvm_err(handler: &rustc_errors::Handler, msg: &str) -> FatalError {
     match llvm::last_error() {
         Some(err) => handler.fatal(&format!("{}: {}", msg, err)),
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index df442609052..f868385ee86 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -21,7 +21,7 @@ use rustc_session::Session;
 use rustc_span::source_map::{Span, DUMMY_SP};
 use rustc_span::symbol::Symbol;
 use rustc_target::abi::{HasDataLayout, LayoutOf, PointeeInfo, Size, TargetDataLayout, VariantIdx};
-use rustc_target::spec::{HasTargetSpec, RelocModel, Target};
+use rustc_target::spec::{HasTargetSpec, RelocModel, Target, TlsModel};
 
 use std::cell::{Cell, RefCell};
 use std::ffi::CStr;
@@ -87,19 +87,12 @@ pub struct CodegenCx<'ll, 'tcx> {
     local_gen_sym_counter: Cell<usize>,
 }
 
-fn get_tls_model(sess: &Session) -> llvm::ThreadLocalMode {
-    let tls_model_arg = match sess.opts.debugging_opts.tls_model {
-        Some(ref s) => &s[..],
-        None => &sess.target.target.options.tls_model[..],
-    };
-
-    match crate::back::write::TLS_MODEL_ARGS.iter().find(|&&arg| arg.0 == tls_model_arg) {
-        Some(x) => x.1,
-        _ => {
-            sess.err(&format!("{:?} is not a valid TLS model", tls_model_arg));
-            sess.abort_if_errors();
-            bug!();
-        }
+fn to_llvm_tls_model(tls_model: TlsModel) -> llvm::ThreadLocalMode {
+    match tls_model {
+        TlsModel::GeneralDynamic => llvm::ThreadLocalMode::GeneralDynamic,
+        TlsModel::LocalDynamic => llvm::ThreadLocalMode::LocalDynamic,
+        TlsModel::InitialExec => llvm::ThreadLocalMode::InitialExec,
+        TlsModel::LocalExec => llvm::ThreadLocalMode::LocalExec,
     }
 }
 
@@ -267,7 +260,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         let check_overflow = tcx.sess.overflow_checks();
 
-        let tls_model = get_tls_model(&tcx.sess);
+        let tls_model = to_llvm_tls_model(tcx.sess.tls_model());
 
         let (llcx, llmod) = (&*llvm_module.llcx, llvm_module.llmod());
 
diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs
index 330d6ea75d2..42302a56b41 100644
--- a/src/librustc_codegen_llvm/lib.rs
+++ b/src/librustc_codegen_llvm/lib.rs
@@ -216,7 +216,7 @@ impl CodegenBackend for LlvmCodegenBackend {
             }
             PrintRequest::TlsModels => {
                 println!("Available TLS models:");
-                for &(name, _) in back::write::TLS_MODEL_ARGS.iter() {
+                for name in &["global-dynamic", "local-dynamic", "initial-exec", "local-exec"] {
                     println!("    {}", name);
                 }
                 println!();