move required_consts check to general post-mono-check function

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -1088,9 +1088,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     InlineAsmOperandRef::InOut { reg, late, in_value, out_place }
                 }
                 mir::InlineAsmOperand::Const { ref value } => {
-                    let const_value = self
-                        .eval_mir_constant(value)
-                        .unwrap_or_else(|_| span_bug!(span, "asm const cannot be resolved"));
+                    let const_value = self.eval_mir_constant(value);
                     let string = common::asm_const_to_str(
                         bx.tcx(),
                         span,

compiler/rustc_codegen_ssa/src/mir/constant.rs

@@ -14,34 +14,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         &self,
         bx: &mut Bx,
         constant: &mir::Constant<'tcx>,
-    ) -> Result<OperandRef<'tcx, Bx::Value>, ErrorHandled> {
-        let val = self.eval_mir_constant(constant)?;
+    ) -> OperandRef<'tcx, Bx::Value> {
+        let val = self.eval_mir_constant(constant);
         let ty = self.monomorphize(constant.ty());
-        Ok(OperandRef::from_const(bx, val, ty))
+        OperandRef::from_const(bx, val, ty)
     }
 
-    pub fn eval_mir_constant(
-        &self,
-        constant: &mir::Constant<'tcx>,
-    ) -> Result<ConstValue<'tcx>, ErrorHandled> {
+    pub fn eval_mir_constant(&self, constant: &mir::Constant<'tcx>) -> ConstValue<'tcx> {
         self.monomorphize(constant.literal)
             .eval(self.cx.tcx(), ty::ParamEnv::reveal_all(), Some(constant.span))
-            .map_err(|err| {
-                match err {
-                    ErrorHandled::Reported(_) => {
-                        self.cx
-                            .tcx()
-                            .sess
-                            .emit_err(errors::ErroneousConstant { span: constant.span });
-                    }
-                    ErrorHandled::TooGeneric => {
-                        self.cx.tcx().sess.diagnostic().emit_bug(
-                            errors::PolymorphicConstantTooGeneric { span: constant.span },
-                        );
-                    }
-                }
-                err
-            })
+            .expect("erroneous constant not captured by required_consts")
     }
 
     /// This is a convenience helper for `simd_shuffle_indices`. It has the precondition

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -579,23 +579,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     if let Some(dbg_var) = dbg_var {
                         let Some(dbg_loc) = self.dbg_loc(var.source_info) else { continue };
 
-                        if let Ok(operand) = self.eval_mir_constant_to_operand(bx, &c) {
-                            self.set_debug_loc(bx, var.source_info);
-                            let base = Self::spill_operand_to_stack(
-                                operand,
-                                Some(var.name.to_string()),
-                                bx,
-                            );
+                        let operand = self.eval_mir_constant_to_operand(bx, &c);
+                        self.set_debug_loc(bx, var.source_info);
+                        let base =
+                            Self::spill_operand_to_stack(operand, Some(var.name.to_string()), bx);
 
-                            bx.dbg_var_addr(
-                                dbg_var,
-                                dbg_loc,
-                                base.llval,
-                                Size::ZERO,
-                                &[],
-                                fragment,
-                            );
-                        }
+                        bx.dbg_var_addr(dbg_var, dbg_loc, base.llval, Size::ZERO, &[], fragment);
                     }
                 }
             }

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -1,4 +1,5 @@
 use crate::base;
+use crate::errors;
 use crate::traits::*;
 use rustc_index::bit_set::BitSet;
 use rustc_index::IndexVec;
@@ -212,24 +213,21 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
     fx.per_local_var_debug_info = fx.compute_per_local_var_debug_info(&mut start_bx);
 
-    // Evaluate all required consts; codegen later assumes that CTFE will never fail.
-    let mut all_consts_ok = true;
-    for const_ in &mir.required_consts {
-        if let Err(err) = fx.eval_mir_constant(const_) {
-            all_consts_ok = false;
-            match err {
-                // errored or at least linted
-                ErrorHandled::Reported(_) => {}
-                ErrorHandled::TooGeneric => {
-                    span_bug!(const_.span, "codegen encountered polymorphic constant: {:?}", err)
-                }
-            }
+    // Rust post-monomorphization checks; we later rely on them.
+    match mir.post_mono_checks(cx.tcx(), ty::ParamEnv::reveal_all(), |c| Ok(fx.monomorphize(c))) {
+        Ok(()) => {}
+        Err(ErrorHandled::TooGeneric(span)) => {
+            cx.tcx().sess.diagnostic().emit_bug(errors::PolymorphicConstantTooGeneric { span });
+        }
+        Err(ErrorHandled::Reported(info, span)) => {
+            if !info.is_tainted_by_errors() {
+                cx.tcx().sess.emit_err(errors::ErroneousConstant { span });
+            }
+            // This IR shouldn't ever be emitted, but let's try to guard against any of this code
+            // ever running.
+            start_bx.abort();
+            return;
         }
-    }
-    if !all_consts_ok {
-        // We leave the IR in some half-built state here, and rely on this code not even being
-        // submitted to LLVM once an error was raised.
-        return;
     }
 
     let memory_locals = analyze::non_ssa_locals(&fx);

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -575,12 +575,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 self.codegen_consume(bx, place.as_ref())
             }
 
-            mir::Operand::Constant(ref constant) => {
-                // This cannot fail because we checked all required_consts in advance.
-                self.eval_mir_constant_to_operand(bx, constant).unwrap_or_else(|_err| {
-                    span_bug!(constant.span, "erroneous constant not captured by required_consts")
-                })
-            }
+            mir::Operand::Constant(ref constant) => self.eval_mir_constant_to_operand(bx, constant),
         }
     }
 }