Quality sprint: remove LLVM backend, fix generics crashes, align docs, wire LSP

.github/workflows/ci.yml

@@ -43,7 +43,7 @@ jobs:
           key: ${{ runner.os }}-cargo-clippy-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: cargo clippy
-        run: cargo clippy --manifest-path turbo/Cargo.toml --workspace --exclude turbo-codegen-llvm --all-targets -- -D warnings
+        run: cargo clippy --manifest-path turbo/Cargo.toml --workspace --all-targets -- -D warnings
 
   doc:
     name: Rustdoc
@@ -65,12 +65,11 @@ jobs:
 
       # Build all crate docs with warnings as errors. Catches broken
       # intra-doc links, invalid HTML in doc comments, and busted Rust
-      # examples in doc-tests. The LLVM backend is excluded to keep this
-      # job hermetic — it has its own dedicated job below.
+      # examples in doc-tests.
       - name: cargo doc
         env:
           RUSTDOCFLAGS: "-D warnings"
-        run: cargo doc --no-deps --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo doc --no-deps --workspace --manifest-path turbo/Cargo.toml
 
   test:
     name: Unit tests (${{ matrix.os }})
@@ -95,7 +94,7 @@ jobs:
           key: ${{ runner.os }}-cargo-test-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: cargo test
-        run: cargo test --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo test --workspace --manifest-path turbo/Cargo.toml
 
   integration:
     name: Integration tests (${{ matrix.os }})
@@ -120,7 +119,7 @@ jobs:
           key: ${{ runner.os }}-cargo-integration-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: Build release
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Run integration tests
         run: ./tests/run_tests.sh
@@ -145,7 +144,7 @@ jobs:
           key: ${{ runner.os }}-cargo-overflow-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: cargo test (overflow-checks enabled)
-        run: cargo test --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo test --workspace --manifest-path turbo/Cargo.toml
         env:
           RUSTFLAGS: "-C overflow-checks=on"
 
@@ -168,7 +167,7 @@ jobs:
           key: ${{ runner.os }}-cargo-build-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: Build
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Report binary size
         run: |
@@ -193,67 +192,6 @@ jobs:
         run: bash tests.sh
         working-directory: turbo/crates/turbo-codegen-cranelift/runtime
 
-  llvm-backend:
-    name: LLVM backend (build + test)
-    runs-on: ubuntu-latest
-    # Hard-required now that struct destructuring, if-let, and optional
-    # chaining are implemented. The three features were the last TODOs
-    # gating the fence; see CHANGELOG.md under [Unreleased] for details.
-    # Only run when LLVM-related files change, or on pushes to master
-    if: >-
-      github.event_name == 'push' ||
-      github.event_name == 'pull_request'
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-
-      - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3.0.2
-        id: filter
-        with:
-          filters: |
-            llvm:
-              - 'turbo/crates/turbo-codegen-llvm/**'
-              - 'turbo/crates/turbo-ast/**'
-              - '.github/workflows/ci.yml'
-
-      - uses: dtolnay/rust-toolchain@e97e2d8cc328f1b50210efc529dca0028893a2d9 # v1
-        with:
-          toolchain: stable
-        if: steps.filter.outputs.llvm == 'true' || github.event_name == 'push'
-
-      - name: Install LLVM 18
-        if: steps.filter.outputs.llvm == 'true' || github.event_name == 'push'
-        run: |
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo apt-get update
-          sudo apt-get install -y llvm-18-dev libpolly-18-dev
-
-      - uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
-        if: steps.filter.outputs.llvm == 'true' || github.event_name == 'push'
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            turbo/target
-          key: ${{ runner.os }}-cargo-llvm-${{ hashFiles('turbo/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-llvm-
-
-      - name: Build LLVM backend
-        if: steps.filter.outputs.llvm == 'true' || github.event_name == 'push'
-        run: cargo build --manifest-path turbo/Cargo.toml -p turbo-codegen-llvm
-        env:
-          LLVM_SYS_180_PREFIX: /usr/lib/llvm-18
-
-      - name: Test LLVM backend
-        if: steps.filter.outputs.llvm == 'true' || github.event_name == 'push'
-        run: cargo test --manifest-path turbo/Cargo.toml -p turbo-codegen-llvm
-        env:
-          LLVM_SYS_180_PREFIX: /usr/lib/llvm-18
-
-      - name: Skip notice
-        if: steps.filter.outputs.llvm != 'true' && github.event_name != 'push'
-        run: echo "No LLVM-related files changed — skipping build and test."
-
   website:
     name: Website lint + build
     runs-on: ubuntu-latest
@@ -301,7 +239,7 @@ jobs:
           key: ${{ runner.os }}-cargo-parity-${{ hashFiles('turbo/Cargo.lock') }}
 
       - name: Build release
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Run parity tests
         run: ./tests/parity/run_parity.sh

.github/workflows/nightly.yml

@@ -31,13 +31,13 @@ jobs:
         run: cargo fmt --manifest-path turbo/Cargo.toml --all -- --check
 
       - name: cargo clippy -D warnings
-        run: cargo clippy --manifest-path turbo/Cargo.toml --workspace --exclude turbo-codegen-llvm --all-targets -- -D warnings
+        run: cargo clippy --manifest-path turbo/Cargo.toml --workspace --all-targets -- -D warnings
 
       - name: cargo test
-        run: cargo test --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo test --workspace --manifest-path turbo/Cargo.toml
 
       - name: Build release for integration + parity
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Integration tests
         run: ./tests/run_tests.sh
@@ -50,7 +50,7 @@ jobs:
       - name: cargo doc -D warnings
         env:
           RUSTDOCFLAGS: "-D warnings"
-        run: cargo doc --no-deps --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo doc --no-deps --workspace --manifest-path turbo/Cargo.toml
 
       - uses: taiki-e/install-action@9545a0634ccdca487a09cde61d362f0bc5fb5df9 # v2.61.4
         with:
@@ -74,13 +74,6 @@ jobs:
       #   in a dashboard nobody watches. Future improvement: add it back
       #   if/when we want to track soft-fail trends across days (e.g.
       #   feed the hash diff into a cross-build observability bucket).
-      #
-      # `llvm-backend` is *not* omitted: ci.yml path-gates it so PRs
-      # don't pay the LLVM build cost on unrelated changes, but the
-      # nightly canary runs on master nightly and exists exactly to
-      # catch backend rot, so we run it for real (no path filter, no
-      # continue-on-error). The LLVM toolchain install step matches
-      # the one in ci.yml exactly.
 
       - name: C runtime tests
         run: bash tests.sh
@@ -89,36 +82,6 @@ jobs:
       - name: Lint error codes
         run: ./scripts/check_error_codes.sh
 
-      - name: Install LLVM 18 (for llvm-backend)
-        run: |
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo apt-get update
-          sudo apt-get install -y llvm-18-dev libpolly-18-dev
-
-      # Mirror the LLVM cache step from ci.yml so the nightly canary hits the
-      # same cache layer as PR builds. Keeping the key and restore-keys in
-      # lockstep means a cold LLVM 18 build is rare — otherwise this would
-      # add ~10 minutes to every nightly run.
-      - uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            turbo/target
-          key: ${{ runner.os }}-cargo-llvm-${{ hashFiles('turbo/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-llvm-
-
-      - name: Build LLVM backend
-        run: cargo build --manifest-path turbo/Cargo.toml -p turbo-codegen-llvm
-        env:
-          LLVM_SYS_180_PREFIX: /usr/lib/llvm-18
-
-      - name: Test LLVM backend
-        run: cargo test --manifest-path turbo/Cargo.toml -p turbo-codegen-llvm
-        env:
-          LLVM_SYS_180_PREFIX: /usr/lib/llvm-18
-
       - name: Build codegen fuzz binary
         run: cargo build --release --bin codegen-fuzz --manifest-path turbo/fuzz/Cargo.toml
 
@@ -142,7 +105,7 @@ jobs:
           toolchain: stable
 
       - name: Build release binary
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Smoke test
         run: ./turbo/target/release/turbolang --version
@@ -161,7 +124,7 @@ jobs:
           toolchain: stable
 
       - name: Build release
-        run: cargo build --release --workspace --exclude turbo-codegen-llvm --manifest-path turbo/Cargo.toml
+        run: cargo build --release --workspace --manifest-path turbo/Cargo.toml
 
       - name: Package canary
         run: |

.github/workflows/release.yml

@@ -17,18 +17,12 @@ jobs:
           - os: macos-latest
             target: aarch64-apple-darwin
             artifact: turbolang
-            llvm: true
-            llvm_prefix: /opt/homebrew/opt/llvm@18
           - os: macos-latest
             target: x86_64-apple-darwin
             artifact: turbolang
-            llvm: false
-            llvm_prefix: ""
           - os: ubuntu-latest
             target: x86_64-unknown-linux-gnu
             artifact: turbolang
-            llvm: true
-            llvm_prefix: /usr/lib/llvm-18
 
     runs-on: ${{ matrix.os }}
 
@@ -40,17 +34,6 @@ jobs:
           toolchain: stable
           targets: ${{ matrix.target }}
 
-      - name: Install LLVM 18 (macOS)
-        if: runner.os == 'macOS' && matrix.llvm
-        run: brew install llvm@18 zstd
-
-      - name: Install LLVM 18 (Linux)
-        if: runner.os == 'Linux' && matrix.llvm
-        run: |
-          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo apt-get update
-          sudo apt-get install -y llvm-18-dev libpolly-18-dev
-
       - uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
         with:
           path: |
@@ -62,17 +45,7 @@ jobs:
             ${{ runner.os }}-cargo-release-${{ matrix.target }}-
             ${{ runner.os }}-cargo-release-
 
-      - name: Build (Cranelift + LLVM)
-        if: matrix.llvm
-        run: |
-          cd turbo
-          cargo build --release --target ${{ matrix.target }} -p turbo-cli --features turbo-cli/llvm
-        env:
-          LLVM_SYS_180_PREFIX: ${{ matrix.llvm_prefix }}
-          LIBRARY_PATH: ${{ runner.os == 'macOS' && '/opt/homebrew/lib' || '' }}
-
-      - name: Build (Cranelift only)
-        if: "!matrix.llvm"
+      - name: Build (Cranelift)
         run: |
           cd turbo
           cargo build --release --target ${{ matrix.target }} -p turbo-cli
@@ -92,11 +65,11 @@ jobs:
           echo 'fn main() { print("turbo works") }' > /tmp/test.tb
           ./turbo/target/${{ matrix.target }}/release/turbolang run /tmp/test.tb
 
-      - name: Smoke test - LLVM AOT build
-        if: matrix.target != 'x86_64-apple-darwin' && matrix.llvm
+      - name: Smoke test - AOT build
+        if: matrix.target != 'x86_64-apple-darwin'
         run: |
-          ./turbo/target/${{ matrix.target }}/release/turbolang build --llvm /tmp/test.tb -o /tmp/test_llvm
-          /tmp/test_llvm
+          ./turbo/target/${{ matrix.target }}/release/turbolang build /tmp/test.tb -o /tmp/test_aot
+          /tmp/test_aot
 
       - name: Package
         run: |

.gitignore

@@ -15,6 +15,9 @@ node_modules/
 # Build outputs
 turbo_test_build
 hello
+mock_agent
+simple_agent
+benchmark-final.png
 *.o
 *.d
 *.wasm
@@ -32,6 +35,13 @@ docs/superpowers/
 /PLAN-*.md
 /INDEX.md
 /turbo/cow-bug-audit.md
+/AUDIT-REPORT.md
+/FINDINGS-REPORT.md
+/SPRINT-PLAN.md
+/SPRINT-PLAN-*.md
+/STDLIB-ROADMAP.md
+/TODO.md
+/turbo/PHASE1-POLISH-SPRINT.md
 
 # OMX tooling artifacts (logs, plans, state — local only, never committed)
 /.omx/

CHANGELOG.md

@@ -5,6 +5,16 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 
 ## [Unreleased]
 
+### Removed
+- **The experimental LLVM backend (`turbo-codegen-llvm`, `turbolang build --llvm`).**
+  Cranelift is now the single code-generation backend. The LLVM path was a
+  partial second implementation (roughly half the builtins), did not build
+  cleanly from the documented steps, and offered no measured speedup over
+  Cranelift — which already edges out `cc -O2` on the fib benchmark. Removing it
+  eliminates a large duplicated codegen surface and the cost of keeping two
+  backends at parity. A future optimizing backend, if pursued, should lower
+  through a shared mid-level IR rather than re-walking the AST a second time.
+
 ## [0.9.0] - 2026-05-16 — Batteries-Included Stdlib
 
 Major stdlib expansion: 37 new builtins bringing TurboLang from 67 to 104 built-in functions. Inspired by the batteries-included philosophy — every dependency is liability, the stdlib must be complete enough that developers never need a package manager.