Split the ABIs into separate implementations and trait files.

lib/compiler-llvm/src/abi/mod.rs

@@ -0,0 +1,85 @@
+// LLVM implements part of the ABI lowering internally, but also requires that
+// the user pack and unpack values themselves sometimes. This can help the LLVM
+// optimizer by exposing operations to the optimizer, but it requires that the
+// frontend know exactly what IR to produce in order to get the right ABI.
+
+#![deny(dead_code, missing_docs)]
+
+use crate::translator::intrinsics::Intrinsics;
+use inkwell::{
+    attributes::{Attribute, AttributeLoc},
+    builder::Builder,
+    context::Context,
+    targets::TargetMachine,
+    types::FunctionType,
+    values::{BasicValueEnum, CallSiteValue, FunctionValue, PointerValue},
+};
+use wasmer_compiler::CompileError;
+use wasmer_types::FunctionType as FuncSig;
+
+mod aarch64_systemv;
+mod x86_64_systemv;
+
+use aarch64_systemv::Aarch64SystemV;
+use x86_64_systemv::X86_64SystemV;
+
+pub fn get_abi(target_machine: &TargetMachine) -> Box<dyn Abi> {
+    if target_machine
+        .get_triple()
+        .as_str()
+        .to_string_lossy()
+        .starts_with("aarch64")
+    {
+        Box::new(Aarch64SystemV {})
+    } else {
+        Box::new(X86_64SystemV {})
+    }
+}
+
+/// We need to produce different LLVM IR for different platforms. (Contrary to
+/// popular knowledge LLVM IR is not intended to be portable in that way.) This
+/// trait deals with differences between function signatures on different
+/// targets.
+pub trait Abi {
+    /// Given a function definition, retrieve the parameter that is the vmctx pointer.
+    fn get_vmctx_ptr_param<'ctx>(&self, func_value: &FunctionValue<'ctx>) -> PointerValue<'ctx>;
+
+    /// Given a wasm function type, produce an llvm function declaration.
+    fn func_type_to_llvm<'ctx>(
+        &self,
+        context: &'ctx Context,
+        intrinsics: &Intrinsics<'ctx>,
+        sig: &FuncSig,
+    ) -> Result<(FunctionType<'ctx>, Vec<(Attribute, AttributeLoc)>), CompileError>;
+
+    /// Marshall wasm stack values into function parameters.
+    fn args_to_call<'ctx>(
+        &self,
+        alloca_builder: &Builder<'ctx>,
+        func_sig: &FuncSig,
+        ctx_ptr: PointerValue<'ctx>,
+        llvm_fn_ty: &FunctionType<'ctx>,
+        values: &[BasicValueEnum<'ctx>],
+    ) -> Vec<BasicValueEnum<'ctx>>;
+
+    /// Given a CallSite, extract the returned values and return them in a Vec.
+    fn rets_from_call<'ctx>(
+        &self,
+        builder: &Builder<'ctx>,
+        intrinsics: &Intrinsics<'ctx>,
+        call_site: CallSiteValue<'ctx>,
+        func_sig: &FuncSig,
+    ) -> Vec<BasicValueEnum<'ctx>>;
+
+    /// Whether the llvm equivalent of this wasm function has an `sret` attribute.
+    fn is_sret(&self, func_sig: &FuncSig) -> Result<bool, CompileError>;
+
+    /// Pack LLVM IR values representing individual wasm values into the return type for the function.
+    fn pack_values_for_register_return<'ctx>(
+        &self,
+        intrinsics: &Intrinsics<'ctx>,
+        builder: &Builder<'ctx>,
+        values: &[BasicValueEnum<'ctx>],
+        func_type: &FunctionType<'ctx>,
+    ) -> Result<BasicValueEnum<'ctx>, CompileError>;
+}