Avoid some duplication between SimpleCx and CodegenCx

Author: oli-obk

compiler/rustc_codegen_llvm/src/builder.rs

@@ -30,7 +30,7 @@ use tracing::{debug, instrument};
 
 use crate::abi::FnAbiLlvmExt;
 use crate::common::Funclet;
-use crate::context::{CodegenCx, SimpleCx};
+use crate::context::{CodegenCx, FullCx, GenericCx, SCx};
 use crate::llvm::{
     self, AtomicOrdering, AtomicRmwBinOp, BasicBlock, False, GEPNoWrapFlags, Metadata, True,
 };
@@ -40,15 +40,15 @@ use crate::value::Value;
 use crate::{attributes, llvm_util};
 
 #[must_use]
-pub(crate) struct GenericBuilder<'a, 'll, CX: Borrow<SimpleCx<'ll>>> {
+pub(crate) struct GenericBuilder<'a, 'll, CX: Borrow<SCx<'ll>>> {
     pub llbuilder: &'ll mut llvm::Builder<'ll>,
-    pub cx: &'a CX,
+    pub cx: &'a GenericCx<'ll, CX>,
 }
 
-pub(crate) type SBuilder<'a, 'll> = GenericBuilder<'a, 'll, SimpleCx<'ll>>;
-pub(crate) type Builder<'a, 'll, 'tcx> = GenericBuilder<'a, 'll, CodegenCx<'ll, 'tcx>>;
+pub(crate) type SBuilder<'a, 'll> = GenericBuilder<'a, 'll, SCx<'ll>>;
+pub(crate) type Builder<'a, 'll, 'tcx> = GenericBuilder<'a, 'll, FullCx<'ll, 'tcx>>;
 
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> Drop for GenericBuilder<'a, 'll, CX> {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> Drop for GenericBuilder<'a, 'll, CX> {
     fn drop(&mut self) {
         unsafe {
             llvm::LLVMDisposeBuilder(&mut *(self.llbuilder as *mut _));
@@ -87,14 +87,15 @@ impl<'a, 'll> SBuilder<'a, 'll> {
         };
         call
     }
+}
 
-    fn with_scx(scx: &'a SimpleCx<'ll>) -> Self {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+    fn with_cx(scx: &'a GenericCx<'ll, CX>) -> Self {
         // Create a fresh builder from the simple context.
-        let llbuilder = unsafe { llvm::LLVMCreateBuilderInContext(scx.llcx) };
-        SBuilder { llbuilder, cx: scx }
+        let llbuilder = unsafe { llvm::LLVMCreateBuilderInContext(scx.deref().borrow().llcx) };
+        GenericBuilder { llbuilder, cx: scx }
     }
-}
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+
     pub(crate) fn bitcast(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
         unsafe { llvm::LLVMBuildBitCast(self.llbuilder, val, dest_ty, UNNAMED) }
     }
@@ -108,16 +109,17 @@ impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
             llvm::LLVMBuildRet(self.llbuilder, v);
         }
     }
-}
-impl<'a, 'll> SBuilder<'a, 'll> {
-    fn build(cx: &'a SimpleCx<'ll>, llbb: &'ll BasicBlock) -> SBuilder<'a, 'll> {
-        let bx = SBuilder::with_scx(cx);
+
+    fn build(cx: &'a GenericCx<'ll, CX>, llbb: &'ll BasicBlock) -> Self {
+        let bx = Self::with_cx(cx);
         unsafe {
             llvm::LLVMPositionBuilderAtEnd(bx.llbuilder, llbb);
         }
         bx
     }
+}
 
+impl<'a, 'll> SBuilder<'a, 'll> {
     fn check_call<'b>(
         &mut self,
         typ: &str,
@@ -1472,26 +1474,12 @@ impl<'ll> StaticBuilderMethods for Builder<'_, 'll, '_> {
 }
 
 impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
-    fn build(cx: &'a CodegenCx<'ll, 'tcx>, llbb: &'ll BasicBlock) -> Builder<'a, 'll, 'tcx> {
-        let bx = Builder::with_cx(cx);
-        unsafe {
-            llvm::LLVMPositionBuilderAtEnd(bx.llbuilder, llbb);
-        }
-        bx
-    }
-
-    fn with_cx(cx: &'a CodegenCx<'ll, 'tcx>) -> Self {
-        // Create a fresh builder from the crate context.
-        let llbuilder = unsafe { llvm::LLVMCreateBuilderInContext(cx.llcx) };
-        Builder { llbuilder, cx }
-    }
-
     pub(crate) fn llfn(&self) -> &'ll Value {
         unsafe { llvm::LLVMGetBasicBlockParent(self.llbb()) }
     }
 }
 
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
     fn position_at_start(&mut self, llbb: &'ll BasicBlock) {
         unsafe {
             llvm::LLVMRustPositionBuilderAtStart(self.llbuilder, llbb);
@@ -1521,7 +1509,7 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
         }
     }
 }
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
     pub(crate) fn minnum(&mut self, lhs: &'ll Value, rhs: &'ll Value) -> &'ll Value {
         unsafe { llvm::LLVMRustBuildMinNum(self.llbuilder, lhs, rhs) }
     }
@@ -1666,7 +1654,7 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
         Cow::Owned(casted_args)
     }
 }
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
     pub(crate) fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
         unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, UNNAMED) }
     }
@@ -1690,7 +1678,7 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
         self.call_intrinsic(intrinsic, &[self.cx.const_u64(size), ptr]);
     }
 }
-impl<'a, 'll, CX: Borrow<SimpleCx<'ll>>> GenericBuilder<'a, 'll, CX> {
+impl<'a, 'll, CX: Borrow<SCx<'ll>>> GenericBuilder<'a, 'll, CX> {
     pub(crate) fn phi(
         &mut self,
         ty: &'ll Type,

compiler/rustc_codegen_llvm/src/builder/autodiff.rs

@@ -286,7 +286,7 @@ pub(crate) fn differentiate<'ll>(
     }
 
     let diag_handler = cgcx.create_dcx();
-    let cx = SimpleCx { llmod: module.module_llvm.llmod(), llcx: module.module_llvm.llcx };
+    let cx = SimpleCx::new(module.module_llvm.llmod(), module.module_llvm.llcx);
 
     // First of all, did the user try to use autodiff without using the -Zautodiff=Enable flag?
     if !diff_items.is_empty()

compiler/rustc_codegen_llvm/src/context.rs

@@ -1,6 +1,7 @@
 use std::borrow::Borrow;
 use std::cell::{Cell, RefCell};
 use std::ffi::{CStr, c_char, c_uint};
+use std::marker::PhantomData;
 use std::ops::Deref;
 use std::str;
 
@@ -43,18 +44,18 @@ use crate::{attributes, coverageinfo, debuginfo, llvm, llvm_util};
 /// However, there are various cx related functions which we want to be available to the builder and
 /// other compiler pieces. Here we define a small subset which has enough information and can be
 /// moved around more freely.
-pub(crate) struct SimpleCx<'ll> {
+pub(crate) struct SCx<'ll> {
     pub llmod: &'ll llvm::Module,
     pub llcx: &'ll llvm::Context,
 }
 
-impl<'ll> Borrow<SimpleCx<'ll>> for CodegenCx<'ll, '_> {
-    fn borrow(&self) -> &SimpleCx<'ll> {
+impl<'ll> Borrow<SCx<'ll>> for FullCx<'ll, '_> {
+    fn borrow(&self) -> &SCx<'ll> {
         &self.scx
     }
 }
 
-impl<'ll, 'tcx> Deref for CodegenCx<'ll, 'tcx> {
+impl<'ll, 'tcx> Deref for FullCx<'ll, 'tcx> {
     type Target = SimpleCx<'ll>;
 
     #[inline]
@@ -63,10 +64,25 @@ impl<'ll, 'tcx> Deref for CodegenCx<'ll, 'tcx> {
     }
 }
 
+pub(crate) struct GenericCx<'ll, T: Borrow<SCx<'ll>>>(T, PhantomData<SCx<'ll>>);
+
+impl<'ll, T: Borrow<SCx<'ll>>> Deref for GenericCx<'ll, T> {
+    type Target = T;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+pub(crate) type SimpleCx<'ll> = GenericCx<'ll, SCx<'ll>>;
+
 /// There is one `CodegenCx` per codegen unit. Each one has its own LLVM
 /// `llvm::Context` so that several codegen units may be processed in parallel.
 /// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`.
-pub(crate) struct CodegenCx<'ll, 'tcx> {
+pub(crate) type CodegenCx<'ll, 'tcx> = GenericCx<'ll, FullCx<'ll, 'tcx>>;
+
+pub(crate) struct FullCx<'ll, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
     pub scx: SimpleCx<'ll>,
     pub use_dll_storage_attrs: bool,
@@ -581,31 +597,34 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         let isize_ty = Type::ix_llcx(llcx, tcx.data_layout.pointer_size.bits());
 
-        CodegenCx {
-            tcx,
-            scx: SimpleCx { llcx, llmod },
-            use_dll_storage_attrs,
-            tls_model,
-            codegen_unit,
-            instances: Default::default(),
-            vtables: Default::default(),
-            const_str_cache: Default::default(),
-            const_globals: Default::default(),
-            statics_to_rauw: RefCell::new(Vec::new()),
-            used_statics: RefCell::new(Vec::new()),
-            compiler_used_statics: RefCell::new(Vec::new()),
-            type_lowering: Default::default(),
-            scalar_lltypes: Default::default(),
-            isize_ty,
-            coverage_cx,
-            dbg_cx,
-            eh_personality: Cell::new(None),
-            eh_catch_typeinfo: Cell::new(None),
-            rust_try_fn: Cell::new(None),
-            intrinsics: Default::default(),
-            local_gen_sym_counter: Cell::new(0),
-            renamed_statics: Default::default(),
-        }
+        GenericCx(
+            FullCx {
+                tcx,
+                scx: SimpleCx::new(llmod, llcx),
+                use_dll_storage_attrs,
+                tls_model,
+                codegen_unit,
+                instances: Default::default(),
+                vtables: Default::default(),
+                const_str_cache: Default::default(),
+                const_globals: Default::default(),
+                statics_to_rauw: RefCell::new(Vec::new()),
+                used_statics: RefCell::new(Vec::new()),
+                compiler_used_statics: RefCell::new(Vec::new()),
+                type_lowering: Default::default(),
+                scalar_lltypes: Default::default(),
+                isize_ty,
+                coverage_cx,
+                dbg_cx,
+                eh_personality: Cell::new(None),
+                eh_catch_typeinfo: Cell::new(None),
+                rust_try_fn: Cell::new(None),
+                intrinsics: Default::default(),
+                local_gen_sym_counter: Cell::new(0),
+                renamed_statics: Default::default(),
+            },
+            PhantomData,
+        )
     }
 
     pub(crate) fn statics_to_rauw(&self) -> &RefCell<Vec<(&'ll Value, &'ll Value)>> {
@@ -628,7 +647,12 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
         llvm::set_section(g, c"llvm.metadata");
     }
 }
+
 impl<'ll> SimpleCx<'ll> {
+    pub(crate) fn new(llmod: &'ll llvm::Module, llcx: &'ll llvm::Context) -> Self {
+        Self(SCx { llmod, llcx }, PhantomData)
+    }
+
     pub(crate) fn val_ty(&self, v: &'ll Value) -> &'ll Type {
         common::val_ty(v)
     }
@@ -1203,25 +1227,13 @@ impl CodegenCx<'_, '_> {
         name.push_str(&(idx as u64).to_base(ALPHANUMERIC_ONLY));
         name
     }
-
-    /// A wrapper for [`llvm::LLVMSetMetadata`], but it takes `Metadata` as a parameter instead of `Value`.
-    pub(crate) fn set_metadata<'a>(&self, val: &'a Value, kind_id: MetadataType, md: &'a Metadata) {
-        unsafe {
-            let node = llvm::LLVMMetadataAsValue(&self.llcx, md);
-            llvm::LLVMSetMetadata(val, kind_id as c_uint, node);
-        }
-    }
 }
 
-// This is a duplication of the set_metadata function above. However, so far it's the only one
-// shared between both contexts, so it doesn't seem worth it to make the Cx generic like we did it
-// for the Builder.
-impl SimpleCx<'_> {
-    #[allow(unused)]
+impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
     /// A wrapper for [`llvm::LLVMSetMetadata`], but it takes `Metadata` as a parameter instead of `Value`.
     pub(crate) fn set_metadata<'a>(&self, val: &'a Value, kind_id: MetadataType, md: &'a Metadata) {
         unsafe {
-            let node = llvm::LLVMMetadataAsValue(&self.llcx, md);
+            let node = llvm::LLVMMetadataAsValue(self.llcx(), md);
             llvm::LLVMSetMetadata(val, kind_id as c_uint, node);
         }
     }

compiler/rustc_codegen_llvm/src/type_.rs

@@ -1,3 +1,4 @@
+use std::borrow::Borrow;
 use std::{fmt, ptr};
 
 use libc::{c_char, c_uint};
@@ -11,7 +12,7 @@ use rustc_middle::ty::{self, Ty};
 use rustc_target::callconv::{CastTarget, FnAbi};
 
 use crate::abi::{FnAbiLlvmExt, LlvmType};
-use crate::context::{CodegenCx, SimpleCx};
+use crate::context::{CodegenCx, GenericCx, SCx};
 pub(crate) use crate::llvm::Type;
 use crate::llvm::{Bool, False, Metadata, True};
 use crate::type_of::LayoutLlvmExt;
@@ -36,29 +37,29 @@ impl fmt::Debug for Type {
 }
 
 impl<'ll> CodegenCx<'ll, '_> {}
-impl<'ll> SimpleCx<'ll> {
+impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
     pub(crate) fn type_named_struct(&self, name: &str) -> &'ll Type {
         let name = SmallCStr::new(name);
-        unsafe { llvm::LLVMStructCreateNamed(self.llcx, name.as_ptr()) }
+        unsafe { llvm::LLVMStructCreateNamed(self.llcx(), name.as_ptr()) }
     }
 
     pub(crate) fn set_struct_body(&self, ty: &'ll Type, els: &[&'ll Type], packed: bool) {
         unsafe { llvm::LLVMStructSetBody(ty, els.as_ptr(), els.len() as c_uint, packed as Bool) }
     }
     pub(crate) fn type_void(&self) -> &'ll Type {
-        unsafe { llvm::LLVMVoidTypeInContext(self.llcx) }
+        unsafe { llvm::LLVMVoidTypeInContext(self.llcx()) }
     }
     pub(crate) fn type_token(&self) -> &'ll Type {
-        unsafe { llvm::LLVMTokenTypeInContext(self.llcx) }
+        unsafe { llvm::LLVMTokenTypeInContext(self.llcx()) }
     }
 
     pub(crate) fn type_metadata(&self) -> &'ll Type {
-        unsafe { llvm::LLVMMetadataTypeInContext(self.llcx) }
+        unsafe { llvm::LLVMMetadataTypeInContext(self.llcx()) }
     }
 
     ///x Creates an integer type with the given number of bits, e.g., i24
     pub(crate) fn type_ix(&self, num_bits: u64) -> &'ll Type {
-        unsafe { llvm::LLVMIntTypeInContext(self.llcx, num_bits as c_uint) }
+        unsafe { llvm::LLVMIntTypeInContext(self.llcx(), num_bits as c_uint) }
     }
 
     pub(crate) fn type_vector(&self, ty: &'ll Type, len: u64) -> &'ll Type {
@@ -121,19 +122,24 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
         self.type_array(self.type_from_integer(unit), size / unit_size)
     }
 }
-impl<'ll> SimpleCx<'ll> {
+
+impl<'ll, CX: Borrow<SCx<'ll>>> GenericCx<'ll, CX> {
+    pub(crate) fn llcx(&self) -> &'ll llvm::Context {
+        (**self).borrow().llcx
+    }
+
     pub(crate) fn type_variadic_func(&self, args: &[&'ll Type], ret: &'ll Type) -> &'ll Type {
         unsafe { llvm::LLVMFunctionType(ret, args.as_ptr(), args.len() as c_uint, True) }
     }
 
     pub(crate) fn type_i1(&self) -> &'ll Type {
-        unsafe { llvm::LLVMInt1TypeInContext(self.llcx) }
+        unsafe { llvm::LLVMInt1TypeInContext(self.llcx()) }
     }
 
     pub(crate) fn type_struct(&self, els: &[&'ll Type], packed: bool) -> &'ll Type {
         unsafe {
             llvm::LLVMStructTypeInContext(
-                self.llcx,
+                self.llcx(),
                 els.as_ptr(),
                 els.len() as c_uint,
                 packed as Bool,