Auto merge of #31283 - dotdash:32_64_cc, r=alexcrichton

When cross compiling for a target that has a larger usize type than the
host system, we use a truncated value to mark data as dropped,
eventually leading to drop calls on already dropped data. To properly
handle this, the drop pattern needs to be of type u64.

Since C_integral truncates its given value to the requested size anyway,
we can also drop the function that chose between the u32 and u64 values,
and always use the u64 constant.

Fixes #31139

r? @pnkfelix

diff --git a/src/librustc_trans/trans/adt.rs b/src/librustc_trans/trans/adt.rs
index 2c11aad8940441638d4b9a1e4c0515d4197fe501..2b74fa780931409d99f127e7f9f49422022e670f 100644 (file)
--- a/src/librustc_trans/trans/adt.rs
+++ b/src/librustc_trans/trans/adt.rs
@@ -229,28 +229,12 @@ const fn repeat_u8_as_u64(val: u8) -> u64 {
 pub const DTOR_MOVED_HINT: u8 = 0x2d;
 
 pub const DTOR_NEEDED: u8 = 0xd4;
-pub const DTOR_NEEDED_U32: u32 = repeat_u8_as_u32(DTOR_NEEDED);
-pub const DTOR_NEEDED_U64: u64 = repeat_u8_as_u64(DTOR_NEEDED);
 #[allow(dead_code)]
-pub fn dtor_needed_usize(ccx: &CrateContext) -> usize {
-    match &ccx.tcx().sess.target.target.target_pointer_width[..] {
-        "32" => DTOR_NEEDED_U32 as usize,
-        "64" => DTOR_NEEDED_U64 as usize,
-        tws => panic!("Unsupported target word size for int: {}", tws),
-    }
-}
+pub const DTOR_NEEDED_U64: u64 = repeat_u8_as_u64(DTOR_NEEDED);
 
 pub const DTOR_DONE: u8 = 0x1d;
-pub const DTOR_DONE_U32: u32 = repeat_u8_as_u32(DTOR_DONE);
-pub const DTOR_DONE_U64: u64 = repeat_u8_as_u64(DTOR_DONE);
 #[allow(dead_code)]
-pub fn dtor_done_usize(ccx: &CrateContext) -> usize {
-    match &ccx.tcx().sess.target.target.target_pointer_width[..] {
-        "32" => DTOR_DONE_U32 as usize,
-        "64" => DTOR_DONE_U64 as usize,
-        tws => panic!("Unsupported target word size for int: {}", tws),
-    }
-}
+pub const DTOR_DONE_U64: u64 = repeat_u8_as_u64(DTOR_DONE);
 
 fn dtor_to_init_u8(dtor: bool) -> u8 {
     if dtor { DTOR_NEEDED } else { 0 }

diff --git a/src/librustc_trans/trans/glue.rs b/src/librustc_trans/trans/glue.rs
index de4867398b99eba46b3a4e5aeede0b980c38e0c7..12aa2e2e3ea6cf30d5dcb2b532b6958f81a5a2d9 100644 (file)
--- a/src/librustc_trans/trans/glue.rs
+++ b/src/librustc_trans/trans/glue.rs
@@ -514,7 +514,7 @@ fn make_drop_glue<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, v0: ValueRef, g: DropGlueK
     // the special dtor markings.
 
     let inttype = Type::int(bcx.ccx());
-    let dropped_pattern = C_integral(inttype, adt::dtor_done_usize(bcx.fcx.ccx) as u64, false);
+    let dropped_pattern = C_integral(inttype, adt::DTOR_DONE_U64, false);
 
     match t.sty {
         ty::TyBox(content_ty) => {