Auto merge of #109900 - cjgillot:disable-const-prop, r=oli-obk

Only enable ConstProp at mir-opt-level >= 2.

That pass is not responsible for lints any more, so we can restrict it to optimized builds.

This reduces the amount of duplicated const-eval messages.

14 files changed, 8 insertions, 108 deletions

diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index 79a9ac7d20c..c0146e3efb0 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -54,7 +54,7 @@ pub struct ConstProp;
 
 impl<'tcx> MirPass<'tcx> for ConstProp {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        sess.mir_opt_level() >= 1
+        sess.mir_opt_level() >= 2
     }
 
     #[instrument(skip(self, tcx), level = "debug")]
@@ -854,12 +854,6 @@ impl<'tcx> MutVisitor<'tcx> for ConstPropagator<'_, 'tcx> {
         }
     }
 
-    fn visit_constant(&mut self, constant: &mut Constant<'tcx>, location: Location) {
-        trace!("visit_constant: {:?}", constant);
-        self.super_constant(constant, location);
-        self.eval_constant(constant);
-    }
-
     fn visit_assign(
         &mut self,
         place: &mut Place<'tcx>,
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 2e418c1dafc..fc12d423cb0 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -566,8 +566,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
             &separate_const_switch::SeparateConstSwitch,
             &simplify::SimplifyLocals::new("before-const-prop"),
             &copy_prop::CopyProp,
-            //
-            // FIXME(#70073): This pass is responsible for both optimization as well as some lints.
             &const_prop::ConstProp,
             &dataflow_const_prop::DataflowConstProp,
             //
diff --git a/tests/codegen/optimize-attr-1.rs b/tests/codegen/optimize-attr-1.rs
index 22abe06e7a9..1d1f0a38657 100644
--- a/tests/codegen/optimize-attr-1.rs
+++ b/tests/codegen/optimize-attr-1.rs
@@ -8,7 +8,6 @@
 
 // CHECK-LABEL: define{{.*}}i32 @nothing
 // CHECK-SAME: [[NOTHING_ATTRS:#[0-9]+]]
-// NO-OPT: ret i32 4
 // SIZE-OPT: ret i32 4
 // SPEEC-OPT: ret i32 4
 #[no_mangle]
@@ -18,7 +17,6 @@ pub fn nothing() -> i32 {
 
 // CHECK-LABEL: define{{.*}}i32 @size
 // CHECK-SAME: [[SIZE_ATTRS:#[0-9]+]]
-// NO-OPT: ret i32 6
 // SIZE-OPT: ret i32 6
 // SPEED-OPT: ret i32 6
 #[optimize(size)]
@@ -31,7 +29,6 @@ pub fn size() -> i32 {
 // NO-OPT-SAME: [[NOTHING_ATTRS]]
 // SPEED-OPT-SAME: [[NOTHING_ATTRS]]
 // SIZE-OPT-SAME: [[SPEED_ATTRS:#[0-9]+]]
-// NO-OPT: ret i32 8
 // SIZE-OPT: ret i32 8
 // SPEED-OPT: ret i32 8
 #[optimize(speed)]
diff --git a/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir b/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir
deleted file mode 100644
index 1a7fb916e56..00000000000
--- a/tests/mir-opt/div_overflow.const_dividend.PreCodegen.after.mir
+++ /dev/null
@@ -1,17 +0,0 @@
-// MIR for `const_dividend` after PreCodegen
-
-fn const_dividend(_1: i32) -> i32 {
-    debug a => _1;                       // in scope 0 at $DIR/div_overflow.rs:+0:23: +0:24
-    let mut _0: i32;                     // return place in scope 0 at $DIR/div_overflow.rs:+0:34: +0:37
-    let mut _2: bool;                    // in scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
-
-    bb0: {
-        _2 = Eq(_1, const 0_i32);        // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
-        assert(!move _2, "attempt to divide `{}` by zero", const 256_i32) -> bb1; // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
-    }
-
-    bb1: {
-        _0 = Div(const 256_i32, _1);     // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
-        return;                          // scope 0 at $DIR/div_overflow.rs:+2:2: +2:2
-    }
-}
diff --git a/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir b/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir
deleted file mode 100644
index 5526a194be5..00000000000
--- a/tests/mir-opt/div_overflow.const_divisor.PreCodegen.after.mir
+++ /dev/null
@@ -1,11 +0,0 @@
-// MIR for `const_divisor` after PreCodegen
-
-fn const_divisor(_1: i32) -> i32 {
-    debug a => _1;                       // in scope 0 at $DIR/div_overflow.rs:+0:22: +0:23
-    let mut _0: i32;                     // return place in scope 0 at $DIR/div_overflow.rs:+0:33: +0:36
-
-    bb0: {
-        _0 = Div(_1, const 256_i32);     // scope 0 at $DIR/div_overflow.rs:+1:5: +1:12
-        return;                          // scope 0 at $DIR/div_overflow.rs:+2:2: +2:2
-    }
-}
diff --git a/tests/mir-opt/div_overflow.rs b/tests/mir-opt/div_overflow.rs
deleted file mode 100644
index fe34a865b93..00000000000
--- a/tests/mir-opt/div_overflow.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-// ignore-wasm32 compiled with panic=abort by default
-// compile-flags: -Copt-level=0 -Coverflow-checks=yes
-
-// Tests that division with a const does not emit a panicking branch for overflow
-
-// EMIT_MIR div_overflow.const_divisor.PreCodegen.after.mir
-pub fn const_divisor(a: i32) -> i32 {
-    a / 256
-}
-
-// EMIT_MIR div_overflow.const_dividend.PreCodegen.after.mir
-pub fn const_dividend(a: i32) -> i32 {
-    256 / a
-}
-
-fn main() {
-    const_divisor(123);
-    const_dividend(123);
-}
diff --git a/tests/run-make/const_fn_mir/dump.mir b/tests/run-make/const_fn_mir/dump.mir
index ab4084c952a..9cc70d3b0e6 100644
--- a/tests/run-make/const_fn_mir/dump.mir
+++ b/tests/run-make/const_fn_mir/dump.mir
@@ -2,9 +2,15 @@
 // and is subject to change without notice. Knock yourself out.
 fn foo() -> i32 {
     let mut _0: i32;                     // return place in scope 0 at main.rs:4:19: 4:22
+    let mut _1: (i32, bool);             // in scope 0 at main.rs:5:5: 5:10
 
     bb0: {
-        _0 = const 11_i32;               // scope 0 at main.rs:5:5: 5:10
+        _1 = CheckedAdd(const 5_i32, const 6_i32); // scope 0 at main.rs:5:5: 5:10
+        assert(!move (_1.1: bool), "attempt to compute `{} + {}`, which would overflow", const 5_i32, const 6_i32) -> bb1; // scope 0 at main.rs:5:5: 5:10
+    }
+
+    bb1: {
+        _0 = move (_1.0: i32);           // scope 0 at main.rs:5:5: 5:10
         return;                          // scope 0 at main.rs:6:2: 6:2
     }
 }
diff --git a/tests/ui/associated-consts/defaults-not-assumed-fail.stderr b/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
index fb7159e40c9..9b761b00691 100644
--- a/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
+++ b/tests/ui/associated-consts/defaults-not-assumed-fail.stderr
@@ -26,14 +26,6 @@ LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
    |
    = note: this note originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
-  --> $DIR/defaults-not-assumed-fail.rs:33:5
-   |
-LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: this note originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-err-late.stderr b/tests/ui/consts/const-err-late.stderr
index 192b9ba204b..149d3b5236b 100644
--- a/tests/ui/consts/const-err-late.stderr
+++ b/tests/ui/consts/const-err-late.stderr
@@ -28,12 +28,6 @@ note: erroneous constant used
 LL |     black_box((S::<i32>::FOO, S::<u32>::FOO));
    |                ^^^^^^^^^^^^^
 
-note: erroneous constant used
-  --> $DIR/const-err-late.rs:19:16
-   |
-LL |     black_box((S::<i32>::FOO, S::<u32>::FOO));
-   |                ^^^^^^^^^^^^^
-
 error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/const-eval/issue-44578.stderr b/tests/ui/consts/const-eval/issue-44578.stderr
index 0cbf5448000..f3952809e4b 100644
--- a/tests/ui/consts/const-eval/issue-44578.stderr
+++ b/tests/ui/consts/const-eval/issue-44578.stderr
@@ -26,14 +26,6 @@ LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
    |
    = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
-  --> $DIR/issue-44578.rs:25:20
-   |
-LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
-   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/miri_unleashed/assoc_const.stderr b/tests/ui/consts/miri_unleashed/assoc_const.stderr
index e1da43c3aea..8e22cb74bf5 100644
--- a/tests/ui/consts/miri_unleashed/assoc_const.stderr
+++ b/tests/ui/consts/miri_unleashed/assoc_const.stderr
@@ -25,12 +25,6 @@ note: erroneous constant used
 LL |     let y = <String as Bar<Vec<u32>, String>>::F;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
-  --> $DIR/assoc_const.rs:29:13
-   |
-LL |     let y = <String as Bar<Vec<u32>, String>>::F;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 warning: skipping const checks
    |
 help: skipping check that does not even have a feature gate
diff --git a/tests/ui/consts/miri_unleashed/assoc_const_2.stderr b/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
index fc4b18056da..ae7b03fc9dd 100644
--- a/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
+++ b/tests/ui/consts/miri_unleashed/assoc_const_2.stderr
@@ -16,12 +16,6 @@ note: erroneous constant used
 LL |     let y = <String as Bar<String>>::F;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-note: erroneous constant used
-  --> $DIR/assoc_const_2.rs:27:13
-   |
-LL |     let y = <String as Bar<String>>::F;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/consts/uninhabited-const-issue-61744.stderr b/tests/ui/consts/uninhabited-const-issue-61744.stderr
index 3a94e19313f..adefbf336c2 100644
--- a/tests/ui/consts/uninhabited-const-issue-61744.stderr
+++ b/tests/ui/consts/uninhabited-const-issue-61744.stderr
@@ -657,12 +657,6 @@ note: erroneous constant used
 LL |     dbg!(i32::CONSTANT);
    |          ^^^^^^^^^^^^^
 
-note: erroneous constant used
-  --> $DIR/uninhabited-const-issue-61744.rs:18:10
-   |
-LL |     dbg!(i32::CONSTANT);
-   |          ^^^^^^^^^^^^^
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/limits/issue-55878.stderr b/tests/ui/limits/issue-55878.stderr
index 99f1fdf755a..510b36edd8f 100644
--- a/tests/ui/limits/issue-55878.stderr
+++ b/tests/ui/limits/issue-55878.stderr
@@ -25,14 +25,6 @@ LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());
    |
    = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-note: erroneous constant used
-  --> $DIR/issue-55878.rs:7:26
-   |
-LL |     println!("Size: {}", std::mem::size_of::<[u8; u64::MAX as usize]>());
-   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: this note originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0080`.