Add field to FunctionCx for passing caller location.

Author: anp

src/librustc_codegen_ssa/mir/block.rs

@@ -995,13 +995,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         bx: &mut Bx,
         span: Span,
     ) -> OperandRef<'tcx, Bx::Value> {
-        let caller = bx.tcx().sess.source_map().lookup_char_pos(span.lo());
-        let const_loc = bx.tcx().const_caller_location((
-            Symbol::intern(&caller.file.name.to_string()),
-            caller.line as u32,
-            caller.col_display as u32 + 1,
-        ));
-        OperandRef::from_const(bx, const_loc)
+        if let Some(l) = self.caller_location {
+            bx.load_operand(l)
+        } else {
+            let caller = bx.tcx().sess.source_map().lookup_char_pos(span.lo());
+            let const_loc = bx.tcx().const_caller_location((
+                Symbol::intern(&caller.file.name.to_string()),
+                caller.line as u32,
+                caller.col_display as u32 + 1,
+            ));
+            OperandRef::from_const(bx, const_loc)
+        }
     }
 
     fn get_personality_slot(

src/librustc_codegen_ssa/mir/mod.rs

@@ -75,6 +75,9 @@ pub struct FunctionCx<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> {
     locals: IndexVec<mir::Local, LocalRef<'tcx, Bx::Value>>,
 
     per_local_var_debug_info: Option<IndexVec<mir::Local, Vec<debuginfo::VarDebugInfo<'tcx>>>>,
+
+    /// Caller location propagated if this function has `#[track_caller]`.
+    caller_location: Option<PlaceRef<'tcx, Bx::Value>>,
 }
 
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
@@ -176,6 +179,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         locals: IndexVec::new(),
         debug_context,
         per_local_var_debug_info: debuginfo::per_local_var_debug_info(cx.tcx(), mir),
+        caller_location: None,
     };
 
     let memory_locals = analyze::non_ssa_locals(&fx);