Rollup merge of #65340 - bjorn3:cg_ssa_refactor4, r=eddyb

Several changes to the codegen backend organization

* Split functions from values in cg_ssa `BackendTypes`.
* Remove `is_const_integral` function from `ConstMethods`.
* Actually register the invalid monomorphization of intrinsic long diagnostic and remove the `diagnostics` method from `CodegenBackends`, as it was unused.
* Add cg_ssa and cg_utils provided methods to `default_provide`, so codegen backend don't have to do it themself.

Author: tmandry

src/librustc_codegen_llvm/builder.rs

@@ -52,6 +52,7 @@ const UNNAMED: *const c_char = EMPTY_C_STR.as_ptr();
 
 impl BackendTypes for Builder<'_, 'll, 'tcx> {
     type Value = <CodegenCx<'ll, 'tcx> as BackendTypes>::Value;
+    type Function = <CodegenCx<'ll, 'tcx> as BackendTypes>::Function;
     type BasicBlock = <CodegenCx<'ll, 'tcx> as BackendTypes>::BasicBlock;
     type Type = <CodegenCx<'ll, 'tcx> as BackendTypes>::Type;
     type Funclet = <CodegenCx<'ll, 'tcx> as BackendTypes>::Funclet;

src/librustc_codegen_llvm/callee.rs

@@ -33,7 +33,7 @@ pub fn get_fn(
     assert!(!instance.substs.has_param_types());
 
     let sig = instance.fn_sig(cx.tcx());
-    if let Some(&llfn) = cx.instances().borrow().get(&instance) {
+    if let Some(&llfn) = cx.instances.borrow().get(&instance) {
         return llfn;
     }
 

src/librustc_codegen_llvm/common.rs

@@ -2,7 +2,7 @@
 
 //! Code that is useful in various codegen modules.
 
-use crate::llvm::{self, True, False, Bool, BasicBlock, OperandBundleDef};
+use crate::llvm::{self, True, False, Bool, BasicBlock, OperandBundleDef, ConstantInt};
 use crate::abi;
 use crate::consts;
 use crate::type_::Type;
@@ -86,6 +86,8 @@ impl Funclet<'ll> {
 
 impl BackendTypes for CodegenCx<'ll, 'tcx> {
     type Value = &'ll Value;
+    type Function = &'ll Value;
+
     type BasicBlock = &'ll BasicBlock;
     type Type = &'ll Type;
     type Funclet = Funclet<'ll>;
@@ -243,33 +245,23 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         struct_in_context(self.llcx, elts, packed)
     }
 
-    fn const_to_uint(&self, v: &'ll Value) -> u64 {
-        unsafe {
+    fn const_to_opt_uint(&self, v: &'ll Value) -> Option<u64> {
+        try_as_const_integral(v).map(|v| unsafe {
             llvm::LLVMConstIntGetZExtValue(v)
-        }
-    }
-
-    fn is_const_integral(&self, v: &'ll Value) -> bool {
-        unsafe {
-            llvm::LLVMIsAConstantInt(v).is_some()
-        }
+        })
     }
 
     fn const_to_opt_u128(&self, v: &'ll Value, sign_ext: bool) -> Option<u128> {
-        unsafe {
-            if self.is_const_integral(v) {
-                let (mut lo, mut hi) = (0u64, 0u64);
-                let success = llvm::LLVMRustConstInt128Get(v, sign_ext,
-                                                           &mut hi, &mut lo);
-                if success {
-                    Some(hi_lo_to_u128(lo, hi))
-                } else {
-                    None
-                }
+        try_as_const_integral(v).and_then(|v| unsafe {
+            let (mut lo, mut hi) = (0u64, 0u64);
+            let success = llvm::LLVMRustConstInt128Get(v, sign_ext,
+                                                        &mut hi, &mut lo);
+            if success {
+                Some(hi_lo_to_u128(lo, hi))
             } else {
                 None
             }
-        }
+        })
     }
 
     fn scalar_to_backend(
@@ -305,7 +297,7 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                         }
                     }
                     Some(GlobalAlloc::Function(fn_instance)) => {
-                        self.get_fn(fn_instance)
+                        self.get_fn_addr(fn_instance)
                     }
                     Some(GlobalAlloc::Static(def_id)) => {
                         assert!(self.tcx.is_static(def_id));
@@ -386,3 +378,9 @@ pub fn struct_in_context(
 fn hi_lo_to_u128(lo: u64, hi: u64) -> u128 {
     ((hi as u128) << 64) | (lo as u128)
 }
+
+fn try_as_const_integral(v: &'ll Value) -> Option<&'ll ConstantInt> {
+    unsafe {
+        llvm::LLVMIsAConstantInt(v)
+    }
+}

src/librustc_codegen_llvm/context.rs

@@ -20,7 +20,6 @@ use rustc::ty::layout::{
 use rustc::ty::{self, Ty, TyCtxt, Instance};
 use rustc::util::nodemap::FxHashMap;
 use rustc_target::spec::{HasTargetSpec, Target};
-use rustc_codegen_ssa::callee::resolve_and_get_fn;
 use rustc_codegen_ssa::base::wants_msvc_seh;
 use crate::callee::get_fn;
 
@@ -327,11 +326,11 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         &self.vtables
     }
 
-    fn instances(&self) -> &RefCell<FxHashMap<Instance<'tcx>, &'ll Value>> {
-        &self.instances
+    fn get_fn(&self, instance: Instance<'tcx>) -> &'ll Value {
+        get_fn(self, instance)
     }
 
-    fn get_fn(&self, instance: Instance<'tcx>) -> &'ll Value {
+    fn get_fn_addr(&self, instance: Instance<'tcx>) -> &'ll Value {
         get_fn(self, instance)
     }
 
@@ -362,7 +361,14 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let tcx = self.tcx;
         let llfn = match tcx.lang_items().eh_personality() {
             Some(def_id) if !wants_msvc_seh(self.sess()) => {
-                resolve_and_get_fn(self, def_id, tcx.intern_substs(&[]))
+                self.get_fn_addr(
+                    ty::Instance::resolve(
+                        tcx,
+                        ty::ParamEnv::reveal_all(),
+                        def_id,
+                        tcx.intern_substs(&[]),
+                    ).unwrap()
+                )
             }
             _ => {
                 let name = if wants_msvc_seh(self.sess()) {
@@ -390,7 +396,14 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let tcx = self.tcx;
         assert!(self.sess().target.target.options.custom_unwind_resume);
         if let Some(def_id) = tcx.lang_items().eh_unwind_resume() {
-            let llfn = resolve_and_get_fn(self, def_id, tcx.intern_substs(&[]));
+            let llfn = self.get_fn_addr(
+                ty::Instance::resolve(
+                    tcx,
+                    ty::ParamEnv::reveal_all(),
+                    def_id,
+                    tcx.intern_substs(&[]),
+                ).unwrap()
+            );
             unwresume.set(Some(llfn));
             return llfn;
         }

src/librustc_codegen_llvm/error_codes.rs

@@ -20,9 +20,9 @@ use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc::hir;
 use syntax::ast::{self, FloatTy};
 
+use rustc_codegen_ssa::common::span_invalid_monomorphization_error;
 use rustc_codegen_ssa::traits::*;
 
-use rustc::session::Session;
 use syntax_pos::Span;
 
 use std::cmp::Ordering;
@@ -1026,10 +1026,6 @@ fn get_rust_try_fn<'ll, 'tcx>(
     rust_try
 }
 
-fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
-    span_err!(a, b, E0511, "{}", c);
-}
-
 fn generic_simd_intrinsic(
     bx: &mut Builder<'a, 'll, 'tcx>,
     name: &str,

src/librustc_codegen_llvm/intrinsic.rs

@@ -38,7 +38,7 @@ extern crate rustc_fs_util;
 extern crate rustc_driver as _;
 
 #[macro_use] extern crate log;
-#[macro_use] extern crate syntax;
+extern crate syntax;
 extern crate syntax_pos;
 extern crate rustc_errors as errors;
 
@@ -64,8 +64,6 @@ use rustc::util::common::ErrorReported;
 use rustc_codegen_ssa::ModuleCodegen;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
 
-mod error_codes;
-
 mod back {
     pub mod archive;
     pub mod bytecode;
@@ -258,10 +256,6 @@ impl CodegenBackend for LlvmCodegenBackend {
         llvm_util::print_version();
     }
 
-    fn diagnostics(&self) -> &[(&'static str, &'static str)] {
-        &error_codes::DIAGNOSTICS
-    }
-
     fn target_features(&self, sess: &Session) -> Vec<Symbol> {
         target_features(sess)
     }
@@ -271,15 +265,10 @@ impl CodegenBackend for LlvmCodegenBackend {
     }
 
     fn provide(&self, providers: &mut ty::query::Providers<'_>) {
-        rustc_codegen_utils::symbol_names::provide(providers);
-        rustc_codegen_ssa::back::symbol_export::provide(providers);
-        rustc_codegen_ssa::base::provide_both(providers);
         attributes::provide(providers);
     }
 
     fn provide_extern(&self, providers: &mut ty::query::Providers<'_>) {
-        rustc_codegen_ssa::back::symbol_export::provide_extern(providers);
-        rustc_codegen_ssa::base::provide_both(providers);
         attributes::provide_extern(providers);
     }
 

src/librustc_codegen_llvm/lib.rs

@@ -510,6 +510,7 @@ extern { pub type Module; }
 extern { pub type Context; }
 extern { pub type Type; }
 extern { pub type Value; }
+extern { pub type ConstantInt; }
 extern { pub type Metadata; }
 extern { pub type BasicBlock; }
 #[repr(C)]
@@ -719,8 +720,8 @@ extern "C" {
     pub fn LLVMConstInt(IntTy: &Type, N: c_ulonglong, SignExtend: Bool) -> &Value;
     pub fn LLVMConstIntOfArbitraryPrecision(IntTy: &Type, Wn: c_uint, Ws: *const u64) -> &Value;
     pub fn LLVMConstReal(RealTy: &Type, N: f64) -> &Value;
-    pub fn LLVMConstIntGetZExtValue(ConstantVal: &Value) -> c_ulonglong;
-    pub fn LLVMRustConstInt128Get(ConstantVal: &Value, SExt: bool,
+    pub fn LLVMConstIntGetZExtValue(ConstantVal: &ConstantInt) -> c_ulonglong;
+    pub fn LLVMRustConstInt128Get(ConstantVal: &ConstantInt, SExt: bool,
                                   high: &mut u64, low: &mut u64) -> bool;
 
 
@@ -1666,7 +1667,7 @@ extern "C" {
     #[allow(improper_ctypes)]
     pub fn LLVMRustWriteValueToString(value_ref: &Value, s: &RustString);
 
-    pub fn LLVMIsAConstantInt(value_ref: &Value) -> Option<&Value>;
+    pub fn LLVMIsAConstantInt(value_ref: &Value) -> Option<&ConstantInt>;
 
     pub fn LLVMRustPassKind(Pass: &Pass) -> PassKind;
     pub fn LLVMRustFindAndCreatePass(Pass: *const c_char) -> Option<&'static mut Pass>;

src/librustc_codegen_llvm/llvm/ffi.rs

@@ -84,7 +84,7 @@ pub trait BuilderMethods<'a, 'tcx>:
 {
     fn new_block<'b>(
         cx: &'a Self::CodegenCx,
-        llfn: Self::Value,
+        llfn: Self::Function,
         name: &'b str
     ) -> Self;
     /* ... */

src/librustc_codegen_ssa/README.md

@@ -36,7 +36,6 @@ use crate::mir::place::PlaceRef;
 use crate::back::write::{OngoingCodegen, start_async_codegen, submit_pre_lto_module_to_llvm,
     submit_post_lto_module_to_llvm};
 use crate::{MemFlags, CrateInfo};
-use crate::callee;
 use crate::common::{RealPredicate, TypeKind, IntPredicate};
 use crate::meth;
 use crate::mir;
@@ -377,8 +376,7 @@ pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
     let sig = instance.fn_sig(cx.tcx());
     let sig = cx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
 
-    let lldecl = cx.instances().borrow().get(&instance).cloned().unwrap_or_else(||
-        bug!("Instance `{:?}` not already declared", instance));
+    let lldecl = cx.get_fn(instance);
 
     let mir = cx.tcx().instance_mir(instance.def);
     mir::codegen_mir::<Bx>(cx, lldecl, &mir, instance, sig);
@@ -400,7 +398,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'
         return;
     }
 
-    let main_llfn = cx.get_fn(instance);
+    let main_llfn = cx.get_fn_addr(instance);
 
     let et = cx.tcx().entry_fn(LOCAL_CRATE).map(|e| e.1);
     match et {
@@ -455,10 +453,13 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'
 
         let (start_fn, args) = if use_start_lang_item {
             let start_def_id = cx.tcx().require_lang_item(StartFnLangItem, None);
-            let start_fn = callee::resolve_and_get_fn(
-                cx,
-                start_def_id,
-                cx.tcx().intern_substs(&[main_ret_ty.into()]),
+            let start_fn = cx.get_fn_addr(
+                ty::Instance::resolve(
+                    cx.tcx(),
+                    ty::ParamEnv::reveal_all(),
+                    start_def_id,
+                    cx.tcx().intern_substs(&[main_ret_ty.into()]),
+                ).unwrap()
             );
             (start_fn, vec![bx.pointercast(rust_main, cx.type_ptr_to(cx.type_i8p())),
                             arg_argc, arg_argv])