1 files changed, 123 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_gcc/src/allocator.rs b/compiler/rustc_codegen_gcc/src/allocator.rs
new file mode 100644
index 000000000..58efb81e8
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/src/allocator.rs
@@ -0,0 +1,123 @@
+use gccjit::{FunctionType, GlobalKind, ToRValue};
+use rustc_ast::expand::allocator::{AllocatorKind, AllocatorTy, ALLOCATOR_METHODS};
+use rustc_middle::bug;
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config::OomStrategy;
+use rustc_span::symbol::sym;
+
+use crate::GccContext;
+
+pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut GccContext, _module_name: &str, kind: AllocatorKind, has_alloc_error_handler: bool) {
+    let context = &mods.context;
+    let usize =
+        match tcx.sess.target.pointer_width {
+            16 => context.new_type::<u16>(),
+            32 => context.new_type::<u32>(),
+            64 => context.new_type::<u64>(),
+            tws => bug!("Unsupported target word size for int: {}", tws),
+        };
+    let i8 = context.new_type::<i8>();
+    let i8p = i8.make_pointer();
+    let void = context.new_type::<()>();
+
+    for method in ALLOCATOR_METHODS {
+        let mut types = Vec::with_capacity(method.inputs.len());
+        for ty in method.inputs.iter() {
+            match *ty {
+                AllocatorTy::Layout => {
+                    types.push(usize);
+                    types.push(usize);
+                }
+                AllocatorTy::Ptr => types.push(i8p),
+                AllocatorTy::Usize => types.push(usize),
+
+                AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
+            }
+        }
+        let output = match method.output {
+            AllocatorTy::ResultPtr => Some(i8p),
+            AllocatorTy::Unit => None,
+
+            AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
+                panic!("invalid allocator output")
+            }
+        };
+        let name = format!("__rust_{}", method.name);
+
+        let args: Vec<_> = types.iter().enumerate()
+            .map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
+            .collect();
+        let func = context.new_function(None, FunctionType::Exported, output.unwrap_or(void), &args, name, false);
+
+        if tcx.sess.target.options.default_hidden_visibility {
+            // TODO(antoyo): set visibility.
+        }
+        if tcx.sess.must_emit_unwind_tables() {
+            // TODO(antoyo): emit unwind tables.
+        }
+
+        let callee = kind.fn_name(method.name);
+        let args: Vec<_> = types.iter().enumerate()
+            .map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
+            .collect();
+        let callee = context.new_function(None, FunctionType::Extern, output.unwrap_or(void), &args, callee, false);
+        // TODO(antoyo): set visibility.
+
+        let block = func.new_block("entry");
+
+        let args = args
+            .iter()
+            .enumerate()
+            .map(|(i, _)| func.get_param(i as i32).to_rvalue())
+            .collect::<Vec<_>>();
+        let ret = context.new_call(None, callee, &args);
+        //llvm::LLVMSetTailCall(ret, True);
+        if output.is_some() {
+            block.end_with_return(None, ret);
+        }
+        else {
+            block.end_with_void_return(None);
+        }
+
+        // TODO(@Commeownist): Check if we need to emit some extra debugging info in certain circumstances
+        // as described in https://github.com/rust-lang/rust/commit/77a96ed5646f7c3ee8897693decc4626fe380643
+    }
+
+    let types = [usize, usize];
+    let name = "__rust_alloc_error_handler".to_string();
+    let args: Vec<_> = types.iter().enumerate()
+        .map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
+        .collect();
+    let func = context.new_function(None, FunctionType::Exported, void, &args, name, false);
+
+    let kind =
+        if has_alloc_error_handler {
+            AllocatorKind::Global
+        }
+        else {
+            AllocatorKind::Default
+        };
+    let callee = kind.fn_name(sym::oom);
+    let args: Vec<_> = types.iter().enumerate()
+        .map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
+        .collect();
+    let callee = context.new_function(None, FunctionType::Extern, void, &args, callee, false);
+    //llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
+
+    let block = func.new_block("entry");
+
+    let args = args
+        .iter()
+        .enumerate()
+        .map(|(i, _)| func.get_param(i as i32).to_rvalue())
+        .collect::<Vec<_>>();
+    let _ret = context.new_call(None, callee, &args);
+    //llvm::LLVMSetTailCall(ret, True);
+    block.end_with_void_return(None);
+
+    let name = OomStrategy::SYMBOL.to_string();
+    let global = context.new_global(None, GlobalKind::Exported, i8, name);
+    let value = tcx.sess.opts.unstable_opts.oom.should_panic();
+    let value = context.new_rvalue_from_int(i8, value as i32);
+    global.global_set_initializer_rvalue(value);
+}