Implement codegen half of LTO

Author: bjorn3

build_system/build_sysroot.rs

@@ -267,6 +267,9 @@ fn build_clif_sysroot_for_triple(
             prefix.to_str().unwrap()
         ));
     }
+    rustflags.push("-Clto=thin".to_owned());
+    rustflags.push("-Zdylib-lto".to_owned());
+    rustflags.push("-Cembed-bitcode=yes".to_owned());
     compiler.rustflags.extend(rustflags);
     let mut build_cmd = STANDARD_LIBRARY.build(&compiler, dirs);
     if channel == "release" {

build_system/prepare.rs

@@ -45,6 +45,12 @@ codegen-units = 10000
 debug-assertions = false
 overflow-checks = false
 codegen-units = 10000
+
+[profile.dev]
+lto = "thin"
+
+[profile.release]
+lto = "thin"
 "#,
     )
     .unwrap();

build_system/tests.rs

@@ -59,7 +59,7 @@ impl TestCase {
 }
 
 const NO_SYSROOT_SUITE: &[TestCase] = &[
-    TestCase::build_lib("build.mini_core", "example/mini_core.rs", "lib,dylib"),
+    TestCase::build_lib("build.mini_core", "example/mini_core.rs", "lib"),
     TestCase::build_lib("build.example", "example/example.rs", "lib"),
     TestCase::jit_bin("jit.mini_core_hello_world", "example/mini_core_hello_world.rs", "abc bcd"),
     TestCase::build_bin_and_run(
@@ -468,6 +468,7 @@ impl<'a> TestRunner<'a> {
         cmd.arg("--out-dir");
         cmd.arg(format!("{}", BUILD_EXAMPLE_OUT_DIR.to_path(&self.dirs).display()));
         cmd.arg("-Cdebuginfo=2");
+        cmd.arg("-Clto=thin");
         cmd.arg("--target");
         cmd.arg(&self.target_compiler.triple);
         cmd.arg("-Cpanic=abort");

patches/0029-stdlib-dylib-crate-type.patch

@@ -0,0 +1,25 @@
+From 0910cbe862990b0c3a17c67bca199ebb4452b0ec Mon Sep 17 00:00:00 2001
+From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
+Date: Tue, 28 Mar 2023 17:09:01 +0000
+Subject: [PATCH] Disable dylib crate type
+
+---
+ library/std/Cargo.toml  | 2 +-
+ 1 files changed, 1 insertions(+), 1 deletions(-)
+
+diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
+index 598a4bf..3e68680 100644
+--- a/library/std/Cargo.toml
++++ b/library/std/Cargo.toml
+@@ -7,7 +7,7 @@ description = "The Rust Standard Library"
+ edition = "2021"
+ 
+ [lib]
+-crate-type = ["dylib", "rlib"]
++crate-type = ["rlib"]
+ 
+ [dependencies]
+ alloc = { path = "../alloc", public = true }
+-- 
+2.34.1
+

src/driver/aot.rs

@@ -323,13 +323,13 @@ fn produce_final_output_artifacts(
     // These are used in linking steps and will be cleaned up afterward.
 }
 
-struct AOTModule {
-    aot_module: ObjectModule,
-    unwind_context: UnwindContext,
+pub(super) struct AOTModule {
+    pub(super) aot_module: ObjectModule,
+    pub(super) unwind_context: UnwindContext,
 }
 
 impl AOTModule {
-    fn finish(self) -> ObjectProduct {
+    pub(super) fn finish(self) -> ObjectProduct {
         let mut product = self.aot_module.finish();
         self.unwind_context.emit(&mut product);
         product