From 35255a924acd6691ac540ecaa2f13bd1c58292e6 Mon Sep 17 00:00:00 2001
From: Jooris Hadeler <jooris@hadeler.me>
Date: Mon, 20 Apr 2026 23:27:16 +0200
Subject: [PATCH] feat: add a backed using cranelift ir and codegen crates

---
 .gitignore               |   2 +
 Cargo.lock               | 556 +++++++++++++++++++++++++++++++++++++++
 Cargo.toml               |   6 +
 src/backend/cranelift.rs | 225 ++++++++++++++++
 src/backend/mod.rs       |   1 +
 src/main.rs              |  52 +++-
 6 files changed, 834 insertions(+), 8 deletions(-)
 create mode 100644 src/backend/cranelift.rs
 create mode 100644 src/backend/mod.rs

diff --git a/.gitignore b/.gitignore
index ea8c4bf..560ca41 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 /target
+/**/*.o
+a.out
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
index 2245ad6..e62bf18 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,562 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "allocator-api2"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
+
+[[package]]
+name = "anstream"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
+
+[[package]]
+name = "anstyle-parse"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys",
+]
+
+[[package]]
+name = "anyhow"
+version = "1.0.102"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
+
+[[package]]
+name = "arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+
+[[package]]
+name = "bumpalo"
+version = "3.20.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
+dependencies = [
+ "allocator-api2",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "clap"
+version = "4.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2ce8604710f6733aa641a2b3731eaa1e8b3d9973d5e3565da11800813f997a9"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
+
 [[package]]
 name = "compiler"
 version = "0.1.0"
+dependencies = [
+ "clap",
+ "cranelift-codegen",
+ "cranelift-frontend",
+ "cranelift-module",
+ "cranelift-native",
+ "cranelift-object",
+]
+
+[[package]]
+name = "cranelift-assembler-x64"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6edb5bdd1af46714e3224a017fabbbd57f70df4e840eb5ad6a7429dc456119d6"
+dependencies = [
+ "cranelift-assembler-x64-meta",
+]
+
+[[package]]
+name = "cranelift-assembler-x64-meta"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a819599186e1b1a1f88d464e06045696afc7aa3e0cc018aa0b2999cb63d1d088"
+dependencies = [
+ "cranelift-srcgen",
+]
+
+[[package]]
+name = "cranelift-bforest"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36e2c152d488e03c87b913bc2ed3414416eb1e0d66d61b49af60bf456a9665c7"
+dependencies = [
+ "cranelift-entity",
+ "wasmtime-internal-core",
+]
+
+[[package]]
+name = "cranelift-bitset"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6559d4fbc253d1396e1f6beeae57fa88a244f02aaf0cde2a735afd3492d9b2e"
+dependencies = [
+ "wasmtime-internal-core",
+]
+
+[[package]]
+name = "cranelift-codegen"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96d9315d98d6e0a64454d4c83be2ee0e8055c3f80c3b2d7bcad7079f281a06ff"
+dependencies = [
+ "bumpalo",
+ "cranelift-assembler-x64",
+ "cranelift-bforest",
+ "cranelift-bitset",
+ "cranelift-codegen-meta",
+ "cranelift-codegen-shared",
+ "cranelift-control",
+ "cranelift-entity",
+ "cranelift-isle",
+ "gimli",
+ "hashbrown 0.16.1",
+ "libm",
+ "log",
+ "regalloc2",
+ "rustc-hash",
+ "serde",
+ "smallvec",
+ "target-lexicon",
+ "wasmtime-internal-core",
+]
+
+[[package]]
+name = "cranelift-codegen-meta"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d89c00a88081c55e3087c45bebc77e0cc973de2d7b44ef6a943c7122647b89f5"
+dependencies = [
+ "cranelift-assembler-x64-meta",
+ "cranelift-codegen-shared",
+ "cranelift-srcgen",
+ "heck",
+]
+
+[[package]]
+name = "cranelift-codegen-shared"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "879f77c497a1eb6273482aa1ac3b23cb8563ff04edb39ed5dfcfd28c8deff8f5"
+
+[[package]]
+name = "cranelift-control"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "498dc1f17a6910c88316d49c7176d8fa97cf10c30859c32a266040449317f963"
+dependencies = [
+ "arbitrary",
+]
+
+[[package]]
+name = "cranelift-entity"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2acba797f6a46042ce82aaf7680d0c3567fe2001e238db9df649fd104a2727f"
+dependencies = [
+ "cranelift-bitset",
+ "wasmtime-internal-core",
+]
+
+[[package]]
+name = "cranelift-frontend"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4dca3df1d107d98d88f159ad1d5eaa2d5cdb678b3d5bcfadc6fc83d8ebb448ea"
+dependencies = [
+ "cranelift-codegen",
+ "log",
+ "smallvec",
+ "target-lexicon",
+]
+
+[[package]]
+name = "cranelift-isle"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f62dd18116d88bed649871feceda79dad7b59cc685ea8998c2b3e64d0e689602"
+
+[[package]]
+name = "cranelift-module"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb5ca0d214ecee44405ea9f0c65a5318b41ac469e8258fd9fe944e564c1c1b0b"
+dependencies = [
+ "anyhow",
+ "cranelift-codegen",
+ "cranelift-control",
+]
+
+[[package]]
+name = "cranelift-native"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f843b80360d7fdf61a6124642af7597f6d55724cf521210c34af8a1c66daca6e"
+dependencies = [
+ "cranelift-codegen",
+ "libc",
+ "target-lexicon",
+]
+
+[[package]]
+name = "cranelift-object"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d212d15015c374333b11b833111b7c7e686bfaec02385af53611050bce7e9d"
+dependencies = [
+ "anyhow",
+ "cranelift-codegen",
+ "cranelift-control",
+ "cranelift-module",
+ "log",
+ "object",
+ "target-lexicon",
+]
+
+[[package]]
+name = "cranelift-srcgen"
+version = "0.131.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "090ee5de58c6f17eb5e3a5ae8cf1695c7efea04ec4dd0ecba6a5b996c9bad7dc"
+
+[[package]]
+name = "crc32fast"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
+[[package]]
+name = "foldhash"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77ce24cb58228fbb8aa041425bb1050850ac19177686ea6e0f41a70416f56fdb"
+
+[[package]]
+name = "gimli"
+version = "0.33.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bf7f043f89559805f8c7cacc432749b2fa0d0a0a9ee46ce47164ed5ba7f126c"
+dependencies = [
+ "fnv",
+ "hashbrown 0.16.1",
+ "indexmap",
+ "stable_deref_trait",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+dependencies = [
+ "foldhash",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
+
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
+[[package]]
+name = "indexmap"
+version = "2.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
+dependencies = [
+ "equivalent",
+ "hashbrown 0.17.0",
+]
+
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
+[[package]]
+name = "libc"
+version = "0.2.185"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52ff2c0fe9bc6cb6b14a0592c2ff4fa9ceb83eea9db979b0487cd054946a2b8f"
+
+[[package]]
+name = "libm"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6d2cec3eae94f9f509c767b45932f1ada8350c4bdb85af2fcab4a3c14807981"
+
+[[package]]
+name = "log"
+version = "0.4.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
+
+[[package]]
+name = "memchr"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
+
+[[package]]
+name = "object"
+version = "0.39.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63944c133d03f44e75866bbd160b95af0ec3f6a13d936d69d31c81078cbc5baf"
+dependencies = [
+ "crc32fast",
+ "hashbrown 0.16.1",
+ "indexmap",
+ "memchr",
+]
+
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "regalloc2"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de2c52737737f8609e94f975dee22854a2d5c125772d4b1cf292120f4d45c186"
+dependencies = [
+ "allocator-api2",
+ "bumpalo",
+ "hashbrown 0.17.0",
+ "log",
+ "rustc-hash",
+ "smallvec",
+]
+
+[[package]]
+name = "rustc-hash"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "smallvec"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
+
+[[package]]
+name = "stable_deref_trait"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
+
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
+[[package]]
+name = "syn"
+version = "2.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "target-lexicon"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adb6935a6f5c20170eeceb1a3835a49e12e19d792f6dd344ccc76a985ca5a6ca"
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
+[[package]]
+name = "wasmtime-internal-core"
+version = "44.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "816a61a75275c6be435131fc625a4f5956daf24d9f9f59443e81cbef228929b3"
+dependencies = [
+ "hashbrown 0.16.1",
+ "libm",
+]
+
+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 1170539..7e6fc4a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,3 +4,9 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+clap = { version = "4.5", features = ["derive"] }
+cranelift-codegen = "0.131.0"
+cranelift-frontend = "0.131.0"
+cranelift-module = "0.131.0"
+cranelift-object = "0.131.0"
+cranelift-native = "0.131.0"
diff --git a/src/backend/cranelift.rs b/src/backend/cranelift.rs
new file mode 100644
index 0000000..94476d0
--- /dev/null
+++ b/src/backend/cranelift.rs
@@ -0,0 +1,225 @@
+use std::collections::HashMap;
+
+use cranelift_codegen::{
+    Context,
+    control::ControlPlane,
+    ir::{self, AbiParam, InstBuilder, types},
+    settings::{self, Configurable},
+};
+use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext, Variable};
+use cranelift_module::{Linkage, Module, default_libcall_names};
+use cranelift_object::{ObjectBuilder, ObjectModule};
+
+use crate::frontend::{
+    ast::{BinaryOp, UnaryOp},
+    sema::Ty,
+    typed_ast::*,
+};
+
+/// The backend responsible for lowering a `TypedModule` into Cranelift IR and
+/// generating native machine code object files.
+pub struct CraneliftBackend {
+    ctx: Context,
+    builder_context: FunctionBuilderContext,
+    module: ObjectModule,
+}
+
+impl CraneliftBackend {
+    /// Initializes the Cranelift backend with the host's native instruction set architecture (ISA),
+    /// enabling speed optimizations and position-independent code (PIC) generation.
+    pub fn new() -> Self {
+        let mut flag_builder = settings::builder();
+        flag_builder.set("is_pic", "true").unwrap();
+        flag_builder.set("opt_level", "speed").unwrap();
+
+        let isa_builder = cranelift_native::builder().unwrap_or_else(|msg| {
+            panic!("host machine is not supported: {}", msg);
+        });
+
+        let isa = isa_builder
+            .finish(settings::Flags::new(flag_builder))
+            .unwrap();
+
+        let builder = ObjectBuilder::new(isa, "module", default_libcall_names()).unwrap();
+
+        Self {
+            ctx: Context::new(),
+            builder_context: FunctionBuilderContext::new(),
+            module: ObjectModule::new(builder),
+        }
+    }
+
+    /// Compiles a fully typed AST module into native object code.
+    ///
+    /// Returns a tuple containing the generated Cranelift IR (as a human-readable string) and the assembled object file bytes.
+    pub fn compile_module(mut self, module: &TypedModule) -> (String, Vec<u8>) {
+        let mut ir_output = String::new();
+
+        for decl in &module.decls {
+            match decl {
+                TypedDecl::Function {
+                    name,
+                    params,
+                    return_type,
+                    body,
+                } => {
+                    self.compile_function(params, return_type, body);
+
+                    // Run Cranelift's optimization passes before emitting the text IR
+                    let mut ctrl_plane = ControlPlane::default();
+                    self.ctx
+                        .optimize(self.module.isa(), &mut ctrl_plane)
+                        .unwrap();
+
+                    ir_output.push_str(&format!(
+                        "; Function: {}\n{}",
+                        name,
+                        self.ctx.func.to_string()
+                    ));
+                    ir_output.push('\n');
+
+                    let func_id = self
+                        .module
+                        .declare_function(name, Linkage::Export, &self.ctx.func.signature)
+                        .unwrap();
+
+                    self.module.define_function(func_id, &mut self.ctx).unwrap();
+                    self.module.clear_context(&mut self.ctx);
+                }
+            }
+        }
+
+        let obj_bytes = self.module.finish().emit().unwrap();
+        (ir_output, obj_bytes)
+    }
+
+    /// Lowers a single function declaration into Cranelift IR.
+    ///
+    /// This sets up the function signature, ABI parameters, entry block, and declares the parameters as local variables.
+    fn compile_function(&mut self, params: &[(String, Ty)], return_type: &Ty, body: &TypedStmt) {
+        let mut sig = self.module.make_signature();
+
+        for (_, ty) in params {
+            sig.params.push(AbiParam::new(Self::lower_type(ty)));
+        }
+
+        if return_type != &Ty::Unit {
+            sig.returns
+                .push(AbiParam::new(Self::lower_type(return_type)));
+        }
+
+        self.ctx.func.signature = sig;
+        self.ctx.func.name = ir::UserFuncName::user(0, 0);
+
+        let mut builder = FunctionBuilder::new(&mut self.ctx.func, &mut self.builder_context);
+
+        let entry_block = builder.create_block();
+        builder.append_block_params_for_function_params(entry_block);
+        builder.switch_to_block(entry_block);
+        builder.seal_block(entry_block);
+
+        let mut vars = HashMap::new();
+
+        for (i, (param_name, ty)) in params.iter().enumerate() {
+            let var = builder.declare_var(Self::lower_type(ty));
+            let val = builder.block_params(entry_block)[i];
+            builder.def_var(var, val);
+            vars.insert(param_name.clone(), var);
+        }
+
+        let mut trans = FunctionTranslator { builder, vars };
+
+        trans.translate_stmt(body);
+        trans.builder.finalize();
+    }
+
+    /// Maps our semantic types (`Ty`) to Cranelift's internal types (`ir::Type`).
+    fn lower_type(ty: &Ty) -> ir::Type {
+        match ty {
+            Ty::I8 | Ty::U8 => types::I8,
+            Ty::I16 | Ty::U16 => types::I16,
+            Ty::I32 | Ty::U32 => types::I32,
+            Ty::I64 | Ty::U64 => types::I64,
+            Ty::Bool => types::I8, // Booleans are represented as 8-bit integers
+            _ => unimplemented!("Unsupported type for Cranelift lowering: {:?}", ty),
+        }
+    }
+}
+
+/// A visitor that traverses typed statements and expressions, emitting Cranelift IR instructions into the current function builder.
+struct FunctionTranslator<'a> {
+    builder: FunctionBuilder<'a>,
+    vars: HashMap<String, Variable>,
+}
+
+impl<'a> FunctionTranslator<'a> {
+    /// Translates a statement, recursively compiling its inner components.
+    fn translate_stmt(&mut self, stmt: &TypedStmt) {
+        match stmt {
+            TypedStmt::Compound { inner } => {
+                for s in inner {
+                    self.translate_stmt(s);
+                }
+            }
+            TypedStmt::Return { value } => {
+                if let Some(expr) = value {
+                    let val = self.translate_expr(expr);
+                    self.builder.ins().return_(&[val]);
+                } else {
+                    self.builder.ins().return_(&[]);
+                }
+            }
+        }
+    }
+
+    /// Translates an expression into a Cranelift IR value.
+    /// Emits appropriate computation instructions based on operators and operand types.
+    fn translate_expr(&mut self, expr: &TypedExpr) -> ir::Value {
+        match &expr.kind {
+            TypedExprKind::Identifier { name } => {
+                let var = self.vars.get(name).expect("Undeclared variable");
+                self.builder.use_var(*var)
+            }
+            TypedExprKind::Integer { value } => {
+                let ty = CraneliftBackend::lower_type(&expr.ty);
+                self.builder.ins().iconst(ty, *value as i64)
+            }
+            TypedExprKind::Boolean { value } => {
+                let ty = CraneliftBackend::lower_type(&expr.ty);
+                self.builder.ins().iconst(ty, if *value { 1 } else { 0 })
+            }
+            TypedExprKind::Unary { op, expr: inner } => {
+                let inner_val = self.translate_expr(inner);
+                match op {
+                    UnaryOp::Neg => self.builder.ins().ineg(inner_val),
+                }
+            }
+            TypedExprKind::Binary { op, lhs, rhs } => {
+                let lhs_val = self.translate_expr(lhs);
+                let rhs_val = self.translate_expr(rhs);
+
+                let is_signed = matches!(lhs.ty, Ty::I8 | Ty::I16 | Ty::I32 | Ty::I64);
+
+                match op {
+                    BinaryOp::Add => self.builder.ins().iadd(lhs_val, rhs_val),
+                    BinaryOp::Sub => self.builder.ins().isub(lhs_val, rhs_val),
+                    BinaryOp::Mul => self.builder.ins().imul(lhs_val, rhs_val),
+                    BinaryOp::Div => {
+                        if is_signed {
+                            self.builder.ins().sdiv(lhs_val, rhs_val)
+                        } else {
+                            self.builder.ins().udiv(lhs_val, rhs_val)
+                        }
+                    }
+                    BinaryOp::Rem => {
+                        if is_signed {
+                            self.builder.ins().srem(lhs_val, rhs_val)
+                        } else {
+                            self.builder.ins().urem(lhs_val, rhs_val)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/src/backend/mod.rs b/src/backend/mod.rs
new file mode 100644
index 0000000..6d12854
--- /dev/null
+++ b/src/backend/mod.rs
@@ -0,0 +1 @@
+pub mod cranelift;
diff --git a/src/main.rs b/src/main.rs
index 26f9f95..3475d9e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,17 +1,34 @@
-use std::{env::args, fs::read_to_string, process::exit};
+use std::{fs::read_to_string, path::PathBuf, process::exit};
+
+use clap::Parser as ClapParser;
 
 use crate::frontend::parser::Parser;
 use crate::frontend::sema::Sema;
 
+pub mod backend;
 pub mod frontend;
 
-fn main() {
-    let Some(path) = args().nth(1) else {
-        eprintln!("usage: compiler <file>");
-        exit(1);
-    };
+use crate::backend::cranelift::CraneliftBackend;
 
-    let content = read_to_string(&path).unwrap_or_else(|err| {
+#[derive(ClapParser)]
+#[command(version, about, long_about = None)]
+struct Cli {
+    /// The input source file to compile
+    input: String,
+
+    /// The output file path
+    #[arg(short, long)]
+    output: Option<String>,
+
+    /// Emit Cranelift IR instead of an object file
+    #[arg(long)]
+    emit_ir: bool,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    let content = read_to_string(&cli.input).unwrap_or_else(|err| {
         eprintln!("error: failed to read source file ({:?})", err);
         exit(1);
     });
@@ -38,5 +55,24 @@ fn main() {
         exit(1);
     }
 
-    println!("{:#?}", typed_module);
+    let backend = CraneliftBackend::new();
+    let (ir, obj_bytes) = backend.compile_module(&typed_module);
+
+    if cli.emit_ir {
+        println!("{}", ir);
+    } else {
+        let output_path = cli.output.unwrap_or_else(|| {
+            PathBuf::from(&cli.input)
+                .with_extension("o")
+                .to_string_lossy()
+                .into_owned()
+        });
+
+        std::fs::write(&output_path, obj_bytes).unwrap_or_else(|err| {
+            eprintln!("error: failed to write object file: {:?}", err);
+            exit(1);
+        });
+
+        println!("Generated object file: {}", output_path);
+    }
 }