Extract helper method set_metadata_node

Author: Zalathar

compiler/rustc_codegen_llvm/src/asm.rs

@@ -538,9 +538,7 @@ pub(crate) fn inline_asm_call<'ll>(
             bx.const_u64(u64::from(span.lo().to_u32()) | (u64::from(span.hi().to_u32()) << 32)),
         )
     }));
-    let md = unsafe { llvm::LLVMMDNodeInContext2(bx.llcx, srcloc.as_ptr(), srcloc.len()) };
-    let md = bx.get_metadata_value(md);
-    llvm::LLVMSetMetadata(call, kind, md);
+    bx.cx.set_metadata_node(call, kind, &srcloc);
 
     Some(call)
 }

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1,12 +1,12 @@
 use std::borrow::{Borrow, Cow};
+use std::iter;
 use std::ops::Deref;
-use std::{iter, ptr};
 
 use rustc_ast::expand::typetree::FncTree;
 pub(crate) mod autodiff;
 pub(crate) mod gpu_offload;
 
-use libc::{c_char, c_uint, size_t};
+use libc::{c_char, c_uint};
 use rustc_abi as abi;
 use rustc_abi::{Align, Size, WrappingRange};
 use rustc_codegen_ssa::MemFlags;
@@ -396,10 +396,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             md.push(weight(is_cold));
         }
 
-        unsafe {
-            let md_node = llvm::LLVMMDNodeInContext2(self.cx.llcx, md.as_ptr(), md.len() as size_t);
-            self.cx.set_metadata(switch, llvm::MD_prof, md_node);
-        }
+        self.cx.set_metadata_node(switch, llvm::MD_prof, &md);
     }
 
     fn invoke(
@@ -801,22 +798,16 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             return;
         }
 
-        unsafe {
-            let llty = self.cx.val_ty(load);
-            let md = [
-                llvm::LLVMValueAsMetadata(self.cx.const_uint_big(llty, range.start)),
-                llvm::LLVMValueAsMetadata(self.cx.const_uint_big(llty, range.end.wrapping_add(1))),
-            ];
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, md.as_ptr(), md.len());
-            self.set_metadata(load, llvm::MD_range, md);
-        }
+        let llty = self.cx.val_ty(load);
+        let md = [
+            llvm::LLVMValueAsMetadata(self.cx.const_uint_big(llty, range.start)),
+            llvm::LLVMValueAsMetadata(self.cx.const_uint_big(llty, range.end.wrapping_add(1))),
+        ];
+        self.set_metadata_node(load, llvm::MD_range, &md);
     }
 
     fn nonnull_metadata(&mut self, load: &'ll Value) {
-        unsafe {
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, ptr::null(), 0);
-            self.set_metadata(load, llvm::MD_nonnull, md);
-        }
+        self.set_metadata_node(load, llvm::MD_nonnull, &[]);
     }
 
     fn store(&mut self, val: &'ll Value, ptr: &'ll Value, align: Align) -> &'ll Value {
@@ -865,8 +856,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
                     //
                     // [1]: https://llvm.org/docs/LangRef.html#store-instruction
                     let one = llvm::LLVMValueAsMetadata(self.cx.const_i32(1));
-                    let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, &one, 1);
-                    self.set_metadata(store, llvm::MD_nontemporal, md);
+                    self.set_metadata_node(store, llvm::MD_nontemporal, &[one]);
                 }
             }
             store
@@ -1381,10 +1371,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn set_invariant_load(&mut self, load: &'ll Value) {
-        unsafe {
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, ptr::null(), 0);
-            self.set_metadata(load, llvm::MD_invariant_load, md);
-        }
+        self.set_metadata_node(load, llvm::MD_invariant_load, &[]);
     }
 
     fn lifetime_start(&mut self, ptr: &'ll Value, size: Size) {
@@ -1528,25 +1515,16 @@ impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
 }
 impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
     fn align_metadata(&mut self, load: &'ll Value, align: Align) {
-        unsafe {
-            let md = [llvm::LLVMValueAsMetadata(self.cx.const_u64(align.bytes()))];
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, md.as_ptr(), md.len());
-            self.set_metadata(load, llvm::MD_align, md);
-        }
+        let md = [llvm::LLVMValueAsMetadata(self.cx.const_u64(align.bytes()))];
+        self.set_metadata_node(load, llvm::MD_align, &md);
     }
 
     fn noundef_metadata(&mut self, load: &'ll Value) {
-        unsafe {
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, ptr::null(), 0);
-            self.set_metadata(load, llvm::MD_noundef, md);
-        }
+        self.set_metadata_node(load, llvm::MD_noundef, &[]);
     }
 
     pub(crate) fn set_unpredictable(&mut self, inst: &'ll Value) {
-        unsafe {
-            let md = llvm::LLVMMDNodeInContext2(self.cx.llcx, ptr::null(), 0);
-            self.set_metadata(inst, llvm::MD_unpredictable, md);
-        }
+        self.set_metadata_node(inst, llvm::MD_unpredictable, &[]);
     }
 }
 impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {

compiler/rustc_codegen_llvm/src/context.rs

@@ -1002,6 +1002,11 @@ impl CodegenCx<'_, '_> {
 }
 
 impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
+    /// Wrapper for `LLVMMDNodeInContext2`, i.e. `llvm::MDNode::get`.
+    pub(crate) fn md_node_in_context(&self, md_list: &[&'ll Metadata]) -> &'ll Metadata {
+        unsafe { llvm::LLVMMDNodeInContext2(self.llcx(), md_list.as_ptr(), md_list.len()) }
+    }
+
     /// A wrapper for [`llvm::LLVMSetMetadata`], but it takes `Metadata` as a parameter instead of `Value`.
     pub(crate) fn set_metadata<'a>(
         &self,
@@ -1012,6 +1017,20 @@ impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
         let node = self.get_metadata_value(md);
         llvm::LLVMSetMetadata(val, kind_id, node);
     }
+
+    /// Helper method for the sequence of calls:
+    /// - `LLVMMDNodeInContext2` (to create an `llvm::MDNode` from a list of metadata)
+    /// - `LLVMMetadataAsValue` (to adapt that node to an `llvm::Value`)
+    /// - `LLVMSetMetadata` (to set that node as metadata of `kind_id` for `instruction`)
+    pub(crate) fn set_metadata_node(
+        &self,
+        instruction: &'ll Value,
+        kind_id: MetadataKindId,
+        md_list: &[&'ll Metadata],
+    ) {
+        let md = self.md_node_in_context(md_list);
+        self.set_metadata(instruction, kind_id, md);
+    }
 }
 
 impl HasDataLayout for CodegenCx<'_, '_> {