Auto merge of #136454 - matthiaskrgr:rollup-ewejzmp, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #136145 (Test validity of pattern types)
 - #136339 (CompileTest: Add Directives to Ignore `arm-unknown-*` Targets)
 - #136403 (Fix malformed error annotations in a UI test)
 - #136414 (Shorten error message for callable with wrong return type)
 - #136425 (Move `rustc_middle::infer::unify_key`)
 - #136426 (Explain why we retroactively change a static initializer to have a different type)
 - #136445 (Couple of cleanups to DiagCtxt and EarlyDiagCtxt)
 - #136452 (Miri subtree update)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 8 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index 771ebf2057f..c6855dd42e5 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -420,8 +420,14 @@ impl<'ll> CodegenCx<'ll, '_> {
             let g = if val_llty == llty {
                 g
             } else {
-                // If we created the global with the wrong type,
-                // correct the type.
+                // codegen_static_initializer creates the global value just from the
+                // `Allocation` data by generating one big struct value that is just
+                // all the bytes and pointers after each other. This will almost never
+                // match the type that the static was declared with. Unfortunately
+                // we can't just LLVMConstBitCast our way out of it because that has very
+                // specific rules on what can be cast. So instead of adding a new way to
+                // generate static initializers that match the static's type, we picked
+                // the easier option and retroactively change the type of the static item itself.
                 let name = llvm::get_value_name(g).to_vec();
                 llvm::set_value_name(g, b"");