1 files changed, 15 insertions, 4 deletions
diff --git a/src/librustc_trans/llvm_util.rs b/src/librustc_trans/llvm_util.rs
index 214fdbded4e..15988008de2 100644
--- a/src/librustc_trans/llvm_util.rs
+++ b/src/librustc_trans/llvm_util.rs
@@ -19,11 +19,12 @@ use std::ffi::{CStr, CString};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Once;
 
-pub fn init(sess: &Session) {
+static POISONED: AtomicBool = AtomicBool::new(false);
+static INIT: Once = Once::new();
+
+pub(crate) fn init(sess: &Session) {
     unsafe {
         // Before we touch LLVM, make sure that multithreading is enabled.
-        static POISONED: AtomicBool = AtomicBool::new(false);
-        static INIT: Once = Once::new();
         INIT.call_once(|| {
             if llvm::LLVMStartMultithreaded() != 1 {
                 // use an extra bool to make sure that all future usage of LLVM
@@ -40,6 +41,13 @@ pub fn init(sess: &Session) {
     }
 }
 
+fn require_inited() {
+    INIT.call_once(|| bug!("llvm is not initialized"));
+    if POISONED.load(Ordering::SeqCst) {
+        bug!("couldn't enable multi-threaded LLVM");
+    }
+}
+
 unsafe fn configure_llvm(sess: &Session) {
     let mut llvm_c_strs = Vec::new();
     let mut llvm_args = Vec::new();
@@ -125,6 +133,7 @@ pub fn target_feature_whitelist(sess: &Session) -> Vec<&CStr> {
 }
 
 pub fn print_version() {
+    // Can be called without initializing LLVM
     unsafe {
         println!("LLVM version: {}.{}",
                  llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor());
@@ -132,10 +141,12 @@ pub fn print_version() {
 }
 
 pub fn print_passes() {
+    // Can be called without initializing LLVM
     unsafe { llvm::LLVMRustPrintPasses(); }
 }
 
-pub fn print(req: PrintRequest, sess: &Session) {
+pub(crate) fn print(req: PrintRequest, sess: &Session) {
+    require_inited();
     let tm = create_target_machine(sess);
     unsafe {
         match req {