Only embed GIMPLE when EMBED_LTO_BITCODE is set

Author: antoyo

.github/workflows/ci.yml

@@ -46,27 +46,12 @@ jobs:
 
     - name: Install packages
       # `llvm-14-tools` is needed to install the `FileCheck` binary which is used for asm tests.
-      run: |
-        sudo add-apt-repository ppa:ubuntu-toolchain-r/ppa
-        sudo apt update
-        sudo apt-get install ninja-build ripgrep llvm-14-tools
+      run: sudo apt-get install ninja-build ripgrep llvm-14-tools
 
     - name: Install libgccjit12
       if: matrix.libgccjit_version.gcc == 'libgccjit12.so'
       run: sudo apt-get install libgccjit-12-dev
 
-    - name: Download artifact
-      if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
-      uses: dawidd6/action-download-artifact@v2
-      with:
-          workflow: main.yml
-          name: ${{ matrix.libgccjit_version.gcc }}
-          path: gcc-build
-          repo: antoyo/gcc
-          branch: ${{ matrix.libgccjit_version.artifacts_branch }}
-          event: push
-          search_artifacts: true # Because, instead, the action only check the last job ran and that won't work since we want multiple artifacts.
-
     - name: Download artifact
       if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
       uses: dawidd6/action-download-artifact@v2
@@ -89,60 +74,6 @@ jobs:
           sudo dpkg --force-overwrite -i gcc-13/gcc-13.deb
           echo /usr/lib/ > gcc_path
 
-          #echo stddef.h
-          #find / -name stddef.h 2> /dev/null || true
-          #echo "************"
-
-          #echo lto1
-          #find / -name lto1 2> /dev/null || true
-          #echo "************"
-          # /usr/libexec/gcc/x86_64-linux-gnu/13/lto1
-          # /usr/lib/gcc/x86_64-linux-gnu/12/lto1
-
-          #echo lto-wrapper
-          #find / -name lto-wrapper 2> /dev/null || true
-          #echo "************"
-          # /usr/libexec/gcc/x86_64-linux-gnu/13/lto-wrapper
-          # /usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper
-
-          #echo gcc
-          #find / -name gcc 2> /dev/null || true
-          #echo "************"
-
-          #echo liblto_plugin.so
-          #find / -name liblto_plugin.so 2> /dev/null || true
-          #echo "************"
-          # /usr/libexec/gcc/x86_64-linux-gnu/13/liblto_plugin.so
-          # /usr/lib/gcc/x86_64-linux-gnu/12/liblto_plugin.so
-          # /usr/lib/gcc/x86_64-linux-gnu/13/liblto_plugin.so
-
-          #echo $(readlink -f gcc-build/build/gcc) > gcc_path
-          ## NOTE: the filename is still libgccjit.so even when the artifact name is different.
-          #ln gcc-build/build/gcc/libgccjit.so gcc-build/build/gcc/libgccjit.so.0
-          ##mkdir -p /opt/gcc/libexec/gcc/x86_64-linux-gnu/13 /opt/gcc/libexec/x86_64-linux-gnu/13/
-          #sudo mkdir -p /usr/lib/gcc/x86_64-pc-linux-gnu/13.0.0/ /usr/libexec/gcc/x86_64-pc-linux-gnu/13.0.0
-          #sudo cp gcc-build/install/bin/gcc /usr/bin/gcc-13
-          #cd gcc-build/build/gcc
-          #chmod +x lto-wrapper lto1
-          ##sudo cp liblto_plugin.so /usr/lib/gcc/x86_64-pc-linux-gnu/13.0.0/liblto_plugin.so # FIXME: might not work.
-          #sudo cp liblto_plugin.so /usr/libexec/gcc/x86_64-pc-linux-gnu/13.0.0/liblto_plugin.so # TODO: should work.
-          #sudo cp lto1 /usr/libexec/gcc/x86_64-pc-linux-gnu/13.0.0/lto1
-          #sudo cp lto-wrapper /usr/libexec/gcc/x86_64-pc-linux-gnu/13.0.0/lto-wrapper
-
-          # TODO TODO TODO: probably need to build gcc with --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib
-          # TODO TODO TODO: bundle that into a .deb file.
-          # https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=gcc11
-
-          ##cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc_s.so /opt/gcc/libexec/x86_64-linux-gnu/13/
-          ## TODO: copy from version 13.
-          ## TODO: understand why it doesn't pick the one from the version 13 automatically.
-          #sudo cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc_s.so /usr/lib/
-          #sudo cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a /usr/lib
-          ##cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a /opt/gcc/libexec/
-          ##cp /usr/libexec/gcc/x86_64-linux-gnu/13/cc1 /opt/gcc/libexec/gcc/cc1
-          #sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 13
-          #sudo update-alternatives --all
-
     - name: Set env
       run: |
         echo "LIBRARY_PATH=$(cat gcc_path)" >> $GITHUB_ENV

.github/workflows/release.yml

@@ -34,21 +34,18 @@ jobs:
         path: llvm
 
     - name: Install packages
-      run: |
-        sudo add-apt-repository ppa:ubuntu-toolchain-r/ppa
-        sudo apt update
-        sudo apt-get install ninja-build ripgrep gcc-13 gcc-multilib
-
-    - name: Download artifact
-      uses: dawidd6/action-download-artifact@v2
-      with:
-          workflow: main.yml
-          name: ${{ matrix.libgccjit_version.gcc }}
-          path: gcc-build
-          repo: antoyo/gcc
-          branch: ${{ matrix.libgccjit_version.artifacts_branch }}
-          event: push
-          search_artifacts: true # Because, instead, the action only check the last job ran and that won't work since we want multiple artifacts.
+      run: sudo apt-get install ninja-build ripgrep gcc-13
+
+    #- name: Download artifact
+      #uses: dawidd6/action-download-artifact@v2
+      #with:
+          #workflow: main.yml
+          #name: ${{ matrix.libgccjit_version.gcc }}
+          #path: gcc-build
+          #repo: antoyo/gcc
+          #branch: ${{ matrix.libgccjit_version.artifacts_branch }}
+          #event: push
+          #search_artifacts: true # Because, instead, the action only check the last job ran and that won't work since we want multiple artifacts.
 
     - name: Download artifact
       if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
@@ -67,23 +64,6 @@ jobs:
           sudo dpkg --force-overwrite -i gcc-13/gcc-13.deb
           echo /usr/lib/ > gcc_path
 
-          #echo $(readlink -f gcc-build/build/gcc) > gcc_path
-          ## NOTE: the filename is still libgccjit.so even when the artifact name is different.
-          #ln gcc-build/build/gcc/libgccjit.so gcc-build/build/gcc/libgccjit.so.0
-          #mkdir -p /opt/gcc/libexec/gcc/x86_64-linux-gnu/13 /opt/gcc/libexec/x86_64-linux-gnu/13/ /opt/gcc/bin
-          #cp gcc-build/install/bin/gcc /opt/gcc/bin/gcc
-          #cd gcc-build/build/gcc
-          #chmod +x lto-wrapper lto1 /opt/gcc/bin/gcc
-          #cp *lto* /opt/gcc/libexec/gcc/x86_64-linux-gnu/
-          ##cp crt*.o /opt/gcc/libexec/x86_64-linux-gnu/13/
-          #cp crt*.o /opt/gcc/libexec/x86_64-linux-gnu/
-          #cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc_s.so /opt/gcc/libexec/x86_64-linux-gnu/
-          #cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a /opt/gcc/libexec/
-          #sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 13
-          ## TODO: add comment if this fixes the -fno-inline errors.
-          ## TODO: do some tests locally to know which binary needs to be copied from the system installation.
-          ##cp /usr/libexec/gcc/x86_64-linux-gnu/13/lto1 /opt/gcc/libexec/gcc/x86_64-linux-gnu/13/
-
     - name: Set env
       run: |
         echo "LIBRARY_PATH=$(cat gcc_path)" >> $GITHUB_ENV
@@ -120,7 +100,7 @@ jobs:
     - name: Build
       run: |
         ./prepare_build.sh
-        ./build.sh --release --release-sysroot
+        EMBED_LTO_BITCODE=1 ./build.sh --release --release-sysroot
         cargo test
         ./clean_all.sh
 
@@ -129,6 +109,8 @@ jobs:
         git config --global user.email "[email protected]"
         git config --global user.name "User"
         ./prepare.sh
+        # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
+        echo -n 'lto = "fat"' >> build_sysroot/Cargo.toml
 
     # Compile is a separate step, as the actions-rs/cargo action supports error annotations
     - name: Compile
@@ -137,9 +119,9 @@ jobs:
         command: build
         args: --release
 
-    - name: Add more failing tests because of undefined symbol errors
+    - name: Add more failing tests because of undefined symbol errors (FIXME)
       run: cat failing-lto-tests.txt >> failing-ui-tests.txt
 
     - name: Run tests
       run: |
-        ./test.sh --release --clean --release-sysroot --build-sysroot ${{ matrix.commands }}
+        EMBED_LTO_BITCODE=1 ./test.sh --release --clean --release-sysroot --build-sysroot ${{ matrix.commands }}

.github/workflows/stdarch.yml

@@ -34,10 +34,7 @@ jobs:
         path: llvm
 
     - name: Install packages
-      run: |
-        sudo add-apt-repository ppa:ubuntu-toolchain-r/ppa
-        sudo apt update
-        sudo apt-get install ninja-build ripgrep gcc-13 gcc-multilib
+      run: sudo apt-get install ninja-build ripgrep gcc-13 gcc-multilib
 
     - name: Install Intel Software Development Emulator
       if: ${{ matrix.cargo_runner }}
@@ -64,23 +61,22 @@ jobs:
           event: push
           search_artifacts: true # Because, instead, the action only check the last job ran and that won't work since we want multiple artifacts.
 
+    - name: Download artifact
+      if: matrix.libgccjit_version.gcc != 'libgccjit12.so'
+      uses: dawidd6/action-download-artifact@v2
+      with:
+          workflow: main.yml
+          name: gcc-13
+          path: gcc-13
+          repo: antoyo/gcc
+          branch: "master"
+          event: push
+          search_artifacts: true # Because, instead, the action only check the last job ran and that won't work since we want multiple artifacts.
+
     - name: Setup path to libgccjit
       run: |
-          echo $(readlink -f gcc-build/build/gcc) > gcc_path
-          # NOTE: the filename is still libgccjit.so even when the artifact name is different.
-          # TODO: instead, overwrite the system gcc, lto1, …?
-          ln gcc-build/build/gcc/libgccjit.so gcc-build/build/gcc/libgccjit.so.0
-          mkdir -p /opt/gcc/libexec/gcc/x86_64-linux-gnu/13 /opt/gcc/libexec/x86_64-linux-gnu/13/ /opt/gcc/bin /opt/gcc/libexec/gcc/x86_64-linux-gnu/13.0.0
-          cp gcc-build/install/bin/gcc /opt/gcc/bin/gcc
-          cd gcc-build/build/gcc
-          chmod +x lto-wrapper lto1 /opt/gcc/bin/gcc
-          cp *lto* /opt/gcc/libexec/gcc/x86_64-linux-gnu/13/
-          cp *lto* /opt/gcc/libexec/gcc/x86_64-linux-gnu/13.0.0/
-          # TODO: instead of downloading the crt files from the GCC CI, copy them from the system.
-          cp crt*.o /opt/gcc/libexec/x86_64-linux-gnu/13/
-          cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc_s.so /opt/gcc/libexec/x86_64-linux-gnu/13/
-          cp /usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a /opt/gcc/libexec/
-          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 13
+          sudo dpkg --force-overwrite -i gcc-13/gcc-13.deb
+          echo /usr/lib/ > gcc_path
 
     - name: Set env
       run: |
@@ -119,7 +115,7 @@ jobs:
       run: |
         ./prepare_build.sh
         ./build.sh --release --release-sysroot
-        GCC_EXEC_PREFIX=/opt/gcc/libexec/gcc/x86_64-pc-linux-gnu cargo test
+        cargo test
 
     - name: Clean
       if: ${{ !matrix.cargo_runner }}
@@ -154,4 +150,5 @@ jobs:
       if: ${{ matrix.cargo_runner }}
       run: |
         cd build_sysroot/sysroot_src/library/stdarch/
+        # FIXME: these tests fail when the sysroot is compiled with LTO because of a missing symbol in proc-macro.
         STDARCH_TEST_EVERYTHING=1 CHANNEL=release CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER="${{ matrix.cargo_runner }}" TARGET=x86_64-unknown-linux-gnu CG_RUSTFLAGS="-Ainternal_features" ../../../../cargo.sh test -- --skip rtm --skip tbm --skip sse4a

Cargo.toml

@@ -20,7 +20,6 @@ harness = false
 [features]
 default = ["master"]
 master = ["gccjit/master"]
-# TODO: add feature for LTO, given all the setup that is needed (having same versions of gcc, lto1, lto-wrapper, liblto_plugin.so)?
 
 [dependencies]
 gccjit = { git = "https://github.com/antoyo/gccjit.rs" }

Readme.md

@@ -91,7 +91,8 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/cargo.sh run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./test.sh`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-To use LTO, you need to set the variable `FAT_LTO` in addition to setting `lto = "fat"` in the `Cargo.toml`.
+To use LTO, you need to set the variable `FAT_LTO=1` and `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
+Don't set `FAT_LTO` when compiling the sysroot, though: only set `EMBED_LTO_BITCODE=1`.
 
 ### Rustc
 
@@ -202,11 +203,11 @@ error: failed to build archive: failed to open object file: No such file or dire
 ```
 
 That can be caused by the fact that you try to compile with `lto = "fat"`, but you didn't compile the sysroot with LTO.
-TODO: check this ^ .
+(Not sure if that's the reason since I cannot reproduce anymore. Maybe it happened when forgetting setting `FAT_LTO`.)
 
 ### How to debug GCC LTO
 
-Run do the command with `-v -save-temps` and then extract the `lto1` line from the output and run that under the debugger
+Run do the command with `-v -save-temps` and then extract the `lto1` line from the output and run that under the debugger.
 
 ### How to send arguments to the GCC linker
 

build_sysroot/Cargo.toml

@@ -19,5 +19,4 @@ rustc-std-workspace-std = { path = "./sysroot_src/library/rustc-std-workspace-st
 
 [profile.release]
 debug = true
-# FIXME: is this actually needed?
-lto = "fat"
+#lto = "fat" # TODO(antoyo): re-enable when the failing LTO tests regarding proc-macros are fixed.

build_sysroot/build_sysroot.sh

@@ -19,11 +19,7 @@ rm -r sysroot/ 2>/dev/null || true
 export RUSTFLAGS="$RUSTFLAGS -Z force-unstable-if-unmarked"
 if [[ "$1" == "--release" ]]; then
     sysroot_channel='release'
-    # To avoid the -fno-inline errors, use /opt/gcc/bin/gcc instead of cc. With:
-    # -Clinker=/opt/gcc/bin/gcc
-    #LIBRARY_PATH=gcc-build GCC_EXEC_PREFIX=/opt/gcc/libexec/gcc/x86_64-pc-linux-gnu
     RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=3" cargo build --target $TARGET_TRIPLE --release
-    #CG_GCCJIT_DUMP_TREE_ALL=1 CG_GCCJIT_KEEP_INTERMEDIATES=1 RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=3" cargo build --target $TARGET_TRIPLE --release
 else
     sysroot_channel='debug'
     cargo build --target $TARGET_TRIPLE --features compiler_builtins/c

cargo.sh

@@ -20,7 +20,4 @@ fi
 cmd=$1
 shift
 
-# TODO: remove LIBRARY_PATH and GCC_EXEC_PREFIX. Those are used to debug the LTO front-end.
-#LIBRARY_PATH=/home/bouanto/Ordinateur/Programmation/Projets/gcc-repo/gcc-build/build/gcc GCC_EXEC_PREFIX=/opt/gcc/libexec/gcc/x86_64-pc-linux-gnu
-#PATH=$PATH:/opt/gcc/bin
 RUSTDOCFLAGS="$RUSTFLAGS" cargo +${TOOLCHAIN} $cmd $@

config.sh

@@ -55,3 +55,7 @@ export RUSTC_LOG=warn # display metadata load errors
 
 export LD_LIBRARY_PATH="$(pwd)/target/out:$(pwd)/build_sysroot/sysroot/lib/rustlib/$TARGET_TRIPLE/lib:$GCC_PATH"
 export DYLD_LIBRARY_PATH=$LD_LIBRARY_PATH
+# NOTE: To avoid the -fno-inline errors, use /opt/gcc/bin/gcc instead of cc.
+# To do so, add a symlink for cc to /opt/gcc/bin/gcc in our PATH.
+# Another option would be to add the following Rust flag: -Clinker=/opt/gcc/bin/gcc
+export PATH="/opt/gcc/bin:$PATH"

failing-non-lto-tests.txt

@@ -7,3 +7,5 @@ tests/ui/lto/lto-rustc-loads-linker-plugin.rs
 tests/ui/panic-runtime/lto-unwind.rs
 tests/ui/sanitize/issue-111184-generator-witness.rs
 tests/ui/sepcomp/sepcomp-lib-lto.rs
+tests/ui/lto/lto-opt-level-s.rs
+tests/ui/lto/lto-opt-level-z.rs