Use LLVMDIBuilderCreateExpression and adjust our insert function

The `LLVMDIBuilderInsertDeclareRecordAtEnd` function requires LLVM 19, so we
can't use it yet, but we can adjust our own wrapper function to resemble it as
closely as possible.

Author: Zalathar

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -172,14 +172,17 @@ impl<'ll> DebugInfoBuilderMethods for Builder<'_, 'll, '_> {
             addr_ops.push((fragment.end - fragment.start).bits() as u64);
         }
 
+        let expr = unsafe {
+            llvm::LLVMDIBuilderCreateExpression(DIB(self.cx()), addr_ops.as_ptr(), addr_ops.len())
+        };
+
         unsafe {
             // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
-            llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
+            llvm::LLVMRustDIBuilderInsertDeclareRecordAtEnd(
                 DIB(self.cx()),
                 variable_alloca,
                 dbg_var,
-                addr_ops.as_ptr(),
-                addr_ops.len() as c_uint,
+                expr,
                 dbg_loc,
                 self.llbb(),
             );

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1784,6 +1784,12 @@ unsafe extern "C" {
         Data: *const Option<&'ll Metadata>,
         NumElements: size_t,
     ) -> &'ll Metadata;
+
+    pub(crate) fn LLVMDIBuilderCreateExpression<'ll>(
+        Builder: &DIBuilder<'ll>,
+        Addr: *const u64,
+        Length: size_t,
+    ) -> &'ll Metadata;
 }
 
 #[link(name = "llvm-wrapper", kind = "static")]
@@ -2162,14 +2168,15 @@ unsafe extern "C" {
         AlignInBits: u32,
     ) -> &'a DIVariable;
 
-    pub fn LLVMRustDIBuilderInsertDeclareAtEnd<'a>(
-        Builder: &DIBuilder<'a>,
-        Val: &'a Value,
-        VarInfo: &'a DIVariable,
-        AddrOps: *const u64,
-        AddrOpsCount: c_uint,
-        DL: &'a DILocation,
-        InsertAtEnd: &'a BasicBlock,
+    /// Mostly equivalent to `LLVMDIBuilderInsertDeclareRecordAtEnd` in LLVM 19,
+    /// except that this works on LLVM 18 and also doesn't return a value.
+    pub(crate) fn LLVMRustDIBuilderInsertDeclareRecordAtEnd<'ll>(
+        Builder: &DIBuilder<'ll>,
+        Storage: &'ll Value,
+        VarInfo: &'ll Metadata,
+        Expr: &'ll Metadata,
+        DebugLoc: &'ll Metadata,
+        Block: &'ll BasicBlock,
     );
 
     pub fn LLVMRustDIBuilderCreateEnumerator<'a>(

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1058,15 +1058,12 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateVariable(
   }
 }
 
-extern "C" void LLVMRustDIBuilderInsertDeclareAtEnd(
-    LLVMRustDIBuilderRef Builder, LLVMValueRef V, LLVMMetadataRef VarInfo,
-    uint64_t *AddrOps, unsigned AddrOpsCount, LLVMMetadataRef DL,
-    LLVMBasicBlockRef InsertAtEnd) {
-  Builder->insertDeclare(unwrap(V), unwrap<DILocalVariable>(VarInfo),
-                         Builder->createExpression(
-                             llvm::ArrayRef<uint64_t>(AddrOps, AddrOpsCount)),
-                         DebugLoc(cast<MDNode>(unwrap(DL))),
-                         unwrap(InsertAtEnd));
+extern "C" void LLVMRustDIBuilderInsertDeclareRecordAtEnd(
+    LLVMDIBuilderRef Builder, LLVMValueRef Storage, LLVMMetadataRef VarInfo,
+    LLVMMetadataRef Expr, LLVMMetadataRef DebugLoc, LLVMBasicBlockRef Block) {
+  unwrap(Builder)->insertDeclare(
+      unwrap(Storage), unwrap<DILocalVariable>(VarInfo),
+      unwrap<DIExpression>(Expr), unwrap<DILocation>(DebugLoc), unwrap(Block));
 }
 
 extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateEnumerator(