From 9a233bb9dd0783b4819650ed87112dbaf944f353 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Fri, 9 Aug 2024 18:08:34 +0200 Subject: [PATCH] interpret: make identity upcasts a NOP again to avoid them generating a new random vtable --- .../rustc_const_eval/src/interpret/cast.rs | 6 ++ .../consts/const-eval/raw-bytes.32bit.stderr | 22 +++-- .../consts/const-eval/raw-bytes.64bit.stderr | 22 +++-- tests/ui/consts/const-eval/raw-bytes.rs | 4 +- .../ub-incorrect-vtable.32bit.stderr | 54 +++++++----- .../ub-incorrect-vtable.64bit.stderr | 54 +++++++----- .../consts/const-eval/ub-incorrect-vtable.rs | 4 +- tests/ui/consts/const-eval/ub-wide-ptr.rs | 14 +-- tests/ui/consts/const-eval/ub-wide-ptr.stderr | 85 +++++++++++++------ 9 files changed, 173 insertions(+), 92 deletions(-) diff --git a/compiler/rustc_const_eval/src/interpret/cast.rs b/compiler/rustc_const_eval/src/interpret/cast.rs index b2f07de0ac4..f6428104e7a 100644 --- a/compiler/rustc_const_eval/src/interpret/cast.rs +++ b/compiler/rustc_const_eval/src/interpret/cast.rs @@ -400,6 +400,12 @@ fn unsize_into_ptr( } (ty::Dynamic(data_a, _, ty::Dyn), ty::Dynamic(data_b, _, ty::Dyn)) => { let val = self.read_immediate(src)?; + // MIR building generates odd NOP casts, prevent them from causing unexpected trouble. + // See . + // FIXME: ideally we wouldn't have to do this. + if data_a == data_b { + return self.write_immediate(*val, dest); + } // Take apart the old pointer, and find the dynamic type. let (old_data, old_vptr) = val.to_scalar_pair(); let old_data = old_data.to_pointer(self)?; diff --git a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr index 25f17f9c38a..27c85cc8ce4 100644 --- a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr +++ b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr @@ -436,17 +436,27 @@ LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, ╾ALLOC_ID╼ ╾ALLOC_ID╼ │ ╾──╼╾──╼ } -error[E0080]: evaluation of constant value failed - --> $DIR/raw-bytes.rs:196:62 +error[E0080]: it is undefined behavior to use this value + --> $DIR/raw-bytes.rs:196:1 | LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered null pointer, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 8, align: 4) { + ╾ALLOC_ID╼ 00 00 00 00 │ ╾──╼.... + } -error[E0080]: evaluation of constant value failed - --> $DIR/raw-bytes.rs:199:65 +error[E0080]: it is undefined behavior to use this value + --> $DIR/raw-bytes.rs:199:1 | LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC32 as vtable pointer but it does not point to a vtable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC27, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 8, align: 4) { + ╾ALLOC_ID╼ ╾ALLOC_ID╼ │ ╾──╼╾──╼ + } error[E0080]: it is undefined behavior to use this value --> $DIR/raw-bytes.rs:204:1 diff --git a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr index 0fb9694895d..2b0ce99a881 100644 --- a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr +++ b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr @@ -436,17 +436,27 @@ LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, ╾ALLOC_ID╼ ╾ALLOC_ID╼ │ ╾──────╼╾──────╼ } -error[E0080]: evaluation of constant value failed - --> $DIR/raw-bytes.rs:196:62 +error[E0080]: it is undefined behavior to use this value + --> $DIR/raw-bytes.rs:196:1 | LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered null pointer, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 16, align: 8) { + ╾ALLOC_ID╼ 00 00 00 00 00 00 00 00 │ ╾──────╼........ + } -error[E0080]: evaluation of constant value failed - --> $DIR/raw-bytes.rs:199:65 +error[E0080]: it is undefined behavior to use this value + --> $DIR/raw-bytes.rs:199:1 | LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC32 as vtable pointer but it does not point to a vtable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC27, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 16, align: 8) { + ╾ALLOC_ID╼ ╾ALLOC_ID╼ │ ╾──────╼╾──────╼ + } error[E0080]: it is undefined behavior to use this value --> $DIR/raw-bytes.rs:204:1 diff --git a/tests/ui/consts/const-eval/raw-bytes.rs b/tests/ui/consts/const-eval/raw-bytes.rs index de1a81b0024..0df732df30e 100644 --- a/tests/ui/consts/const-eval/raw-bytes.rs +++ b/tests/ui/consts/const-eval/raw-bytes.rs @@ -194,10 +194,10 @@ impl Trait for bool {} //~| expected a boolean const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| null pointer const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| vtable // Uninhabited types diff --git a/tests/ui/consts/const-eval/ub-incorrect-vtable.32bit.stderr b/tests/ui/consts/const-eval/ub-incorrect-vtable.32bit.stderr index 439ccb24e61..5c47cbfdf3b 100644 --- a/tests/ui/consts/const-eval/ub-incorrect-vtable.32bit.stderr +++ b/tests/ui/consts/const-eval/ub-incorrect-vtable.32bit.stderr @@ -1,20 +1,8 @@ -error[E0080]: evaluation of constant value failed - --> $DIR/ub-incorrect-vtable.rs:19:14 - | -LL | unsafe { std::mem::transmute((&92u8, &[0usize, 1usize, 1000usize])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC8 as vtable pointer but it does not point to a vtable - -error[E0080]: evaluation of constant value failed - --> $DIR/ub-incorrect-vtable.rs:24:14 - | -LL | unsafe { std::mem::transmute((&92u8, &[1usize, usize::MAX, 1usize])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC9 as vtable pointer but it does not point to a vtable - error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:33:1 + --> $DIR/ub-incorrect-vtable.rs:18:1 | -LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC1, but expected a vtable pointer +LL | const INVALID_VTABLE_ALIGNMENT: &dyn Trait = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC1, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 8, align: 4) { @@ -22,10 +10,10 @@ LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = } error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:38:1 + --> $DIR/ub-incorrect-vtable.rs:23:1 | -LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC3, but expected a vtable pointer +LL | const INVALID_VTABLE_SIZE: &dyn Trait = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC3, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 8, align: 4) { @@ -33,16 +21,38 @@ LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = } error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:44:1 + --> $DIR/ub-incorrect-vtable.rs:33:1 | -LL | const INVALID_VTABLE_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC5, but expected a vtable pointer +LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC5, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 8, align: 4) { ╾ALLOC4╼ ╾ALLOC5╼ │ ╾──╼╾──╼ } +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-incorrect-vtable.rs:38:1 + | +LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC7, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 8, align: 4) { + ╾ALLOC6╼ ╾ALLOC7╼ │ ╾──╼╾──╼ + } + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-incorrect-vtable.rs:44:1 + | +LL | const INVALID_VTABLE_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC9, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 8, align: 4) { + ╾ALLOC8╼ ╾ALLOC9╼ │ ╾──╼╾──╼ + } + error[E0080]: it is undefined behavior to use this value --> $DIR/ub-incorrect-vtable.rs:91:1 | @@ -51,7 +61,7 @@ LL | const G: Wide = unsafe { Transmute { t: FOO }.u }; | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 8, align: 4) { - ╾ALLOC6╼ ╾ALLOC7╼ │ ╾──╼╾──╼ + ╾ALLOC10╼ ╾ALLOC11╼ │ ╾──╼╾──╼ } error: aborting due to 6 previous errors diff --git a/tests/ui/consts/const-eval/ub-incorrect-vtable.64bit.stderr b/tests/ui/consts/const-eval/ub-incorrect-vtable.64bit.stderr index 89bf959703a..f400073aca2 100644 --- a/tests/ui/consts/const-eval/ub-incorrect-vtable.64bit.stderr +++ b/tests/ui/consts/const-eval/ub-incorrect-vtable.64bit.stderr @@ -1,20 +1,8 @@ -error[E0080]: evaluation of constant value failed - --> $DIR/ub-incorrect-vtable.rs:19:14 - | -LL | unsafe { std::mem::transmute((&92u8, &[0usize, 1usize, 1000usize])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC8 as vtable pointer but it does not point to a vtable - -error[E0080]: evaluation of constant value failed - --> $DIR/ub-incorrect-vtable.rs:24:14 - | -LL | unsafe { std::mem::transmute((&92u8, &[1usize, usize::MAX, 1usize])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC9 as vtable pointer but it does not point to a vtable - error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:33:1 + --> $DIR/ub-incorrect-vtable.rs:18:1 | -LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC1, but expected a vtable pointer +LL | const INVALID_VTABLE_ALIGNMENT: &dyn Trait = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC1, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 16, align: 8) { @@ -22,10 +10,10 @@ LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = } error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:38:1 + --> $DIR/ub-incorrect-vtable.rs:23:1 | -LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC3, but expected a vtable pointer +LL | const INVALID_VTABLE_SIZE: &dyn Trait = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC3, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 16, align: 8) { @@ -33,16 +21,38 @@ LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = } error[E0080]: it is undefined behavior to use this value - --> $DIR/ub-incorrect-vtable.rs:44:1 + --> $DIR/ub-incorrect-vtable.rs:33:1 | -LL | const INVALID_VTABLE_UB: W<&dyn Trait> = - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC5, but expected a vtable pointer +LL | const INVALID_VTABLE_ALIGNMENT_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC5, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 16, align: 8) { ╾ALLOC4╼ ╾ALLOC5╼ │ ╾──────╼╾──────╼ } +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-incorrect-vtable.rs:38:1 + | +LL | const INVALID_VTABLE_SIZE_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC7, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 16, align: 8) { + ╾ALLOC6╼ ╾ALLOC7╼ │ ╾──────╼╾──────╼ + } + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-incorrect-vtable.rs:44:1 + | +LL | const INVALID_VTABLE_UB: W<&dyn Trait> = + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC9, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: 16, align: 8) { + ╾ALLOC8╼ ╾ALLOC9╼ │ ╾──────╼╾──────╼ + } + error[E0080]: it is undefined behavior to use this value --> $DIR/ub-incorrect-vtable.rs:91:1 | @@ -51,7 +61,7 @@ LL | const G: Wide = unsafe { Transmute { t: FOO }.u }; | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: 16, align: 8) { - ╾ALLOC6╼ ╾ALLOC7╼ │ ╾──────╼╾──────╼ + ╾ALLOC10╼ ╾ALLOC11╼ │ ╾──────╼╾──────╼ } error: aborting due to 6 previous errors diff --git a/tests/ui/consts/const-eval/ub-incorrect-vtable.rs b/tests/ui/consts/const-eval/ub-incorrect-vtable.rs index 4325495a380..8058f7693a7 100644 --- a/tests/ui/consts/const-eval/ub-incorrect-vtable.rs +++ b/tests/ui/consts/const-eval/ub-incorrect-vtable.rs @@ -17,12 +17,12 @@ trait Trait {} const INVALID_VTABLE_ALIGNMENT: &dyn Trait = unsafe { std::mem::transmute((&92u8, &[0usize, 1usize, 1000usize])) }; -//~^ ERROR evaluation of constant value failed +//~^^ ERROR it is undefined behavior to use this value //~| vtable const INVALID_VTABLE_SIZE: &dyn Trait = unsafe { std::mem::transmute((&92u8, &[1usize, usize::MAX, 1usize])) }; -//~^ ERROR evaluation of constant value failed +//~^^ ERROR it is undefined behavior to use this value //~| vtable #[repr(transparent)] diff --git a/tests/ui/consts/const-eval/ub-wide-ptr.rs b/tests/ui/consts/const-eval/ub-wide-ptr.rs index 3956146f6ae..991d4424dcf 100644 --- a/tests/ui/consts/const-eval/ub-wide-ptr.rs +++ b/tests/ui/consts/const-eval/ub-wide-ptr.rs @@ -123,13 +123,13 @@ impl Trait for bool {} //~^ ERROR it is undefined behavior to use this value //~| vtable const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92u8, &[0u8; 128])) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| vtable const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92u8, &[0usize; 8])) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| vtable const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u8, &[1usize; 8])) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| vtable const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &[&42u8; 8]))) }; //~^ ERROR it is undefined behavior to use this value @@ -142,10 +142,10 @@ impl Trait for bool {} // # raw trait object const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| null pointer const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) }; -//~^ ERROR evaluation of constant value failed +//~^ ERROR it is undefined behavior to use this value //~| vtable const RAW_TRAIT_OBJ_CONTENT_INVALID: *const dyn Trait = unsafe { mem::transmute::<_, &bool>(&3u8) } as *const dyn Trait; // ok because raw // Officially blessed way to get the vtable @@ -154,12 +154,12 @@ impl Trait for bool {} static mut RAW_TRAIT_OBJ_VTABLE_NULL_THROUGH_REF: *const dyn Trait = unsafe { mem::transmute::<_, &dyn Trait>((&92u8, 0usize)) - //~^ ERROR could not evaluate static initializer + //~^^ ERROR it is undefined behavior to use this value //~| null pointer }; static mut RAW_TRAIT_OBJ_VTABLE_INVALID_THROUGH_REF: *const dyn Trait = unsafe { mem::transmute::<_, &dyn Trait>((&92u8, &3u64)) - //~^ ERROR could not evaluate static initializer + //~^^ ERROR it is undefined behavior to use this value //~| vtable }; diff --git a/tests/ui/consts/const-eval/ub-wide-ptr.stderr b/tests/ui/consts/const-eval/ub-wide-ptr.stderr index c29cc836fff..92f0029a5b3 100644 --- a/tests/ui/consts/const-eval/ub-wide-ptr.stderr +++ b/tests/ui/consts/const-eval/ub-wide-ptr.stderr @@ -218,29 +218,44 @@ LL | const TRAIT_OBJ_INT_VTABLE: W<&dyn Trait> = unsafe { mem::transmute(W((&92u HEX_DUMP } -error[E0080]: evaluation of constant value failed - --> $DIR/ub-wide-ptr.rs:125:57 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:125:1 | LL | const TRAIT_OBJ_UNALIGNED_VTABLE: &dyn Trait = unsafe { mem::transmute((&92u8, &[0u8; 128])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC20 as vtable pointer but it does not point to a vtable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC17, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } -error[E0080]: evaluation of constant value failed - --> $DIR/ub-wide-ptr.rs:128:57 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:128:1 | LL | const TRAIT_OBJ_BAD_DROP_FN_NULL: &dyn Trait = unsafe { mem::transmute((&92u8, &[0usize; 8])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC21 as vtable pointer but it does not point to a vtable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC19, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } -error[E0080]: evaluation of constant value failed - --> $DIR/ub-wide-ptr.rs:131:56 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:131:1 | LL | const TRAIT_OBJ_BAD_DROP_FN_INT: &dyn Trait = unsafe { mem::transmute((&92u8, &[1usize; 8])) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC22 as vtable pointer but it does not point to a vtable + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC21, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } error[E0080]: it is undefined behavior to use this value --> $DIR/ub-wide-ptr.rs:134:1 | LL | const TRAIT_OBJ_BAD_DROP_FN_NOT_FN_PTR: W<&dyn Trait> = unsafe { mem::transmute(W((&92u8, &[&42u8; 8]))) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC17, but expected a vtable pointer + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered ALLOC23, but expected a vtable pointer | = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { @@ -258,29 +273,49 @@ LL | const TRAIT_OBJ_CONTENT_INVALID: &dyn Trait = unsafe { mem::transmute::<_, HEX_DUMP } -error[E0080]: evaluation of constant value failed - --> $DIR/ub-wide-ptr.rs:144:62 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:144:1 | LL | const RAW_TRAIT_OBJ_VTABLE_NULL: *const dyn Trait = unsafe { mem::transmute((&92u8, 0usize)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered null pointer, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } -error[E0080]: evaluation of constant value failed - --> $DIR/ub-wide-ptr.rs:147:65 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:147:1 | LL | const RAW_TRAIT_OBJ_VTABLE_INVALID: *const dyn Trait = unsafe { mem::transmute((&92u8, &3u64)) }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC23 as vtable pointer but it does not point to a vtable - -error[E0080]: could not evaluate static initializer - --> $DIR/ub-wide-ptr.rs:156:5 + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC28, but expected a vtable pointer | -LL | mem::transmute::<_, &dyn Trait>((&92u8, 0usize)) - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ out-of-bounds pointer use: expected a pointer to some allocation, but got a null pointer + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } -error[E0080]: could not evaluate static initializer - --> $DIR/ub-wide-ptr.rs:161:5 +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:155:1 | -LL | mem::transmute::<_, &dyn Trait>((&92u8, &3u64)) - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using ALLOC24 as vtable pointer but it does not point to a vtable +LL | static mut RAW_TRAIT_OBJ_VTABLE_NULL_THROUGH_REF: *const dyn Trait = unsafe { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered null pointer, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } + +error[E0080]: it is undefined behavior to use this value + --> $DIR/ub-wide-ptr.rs:160:1 + | +LL | static mut RAW_TRAIT_OBJ_VTABLE_INVALID_THROUGH_REF: *const dyn Trait = unsafe { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered ALLOC31, but expected a vtable pointer + | + = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior. + = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) { + HEX_DUMP + } error: aborting due to 29 previous errors