Ship brp-llvm-compile-lto-elf script

Resolves: rhbz#2022522

brp-llvm-compile-lto-elf

@@ -0,0 +1,52 @@
+#!/usr/bin/bash -eu
+
+
+if [ -z "$RPM_BUILD_ROOT" ] || [ "$RPM_BUILD_ROOT" = "/" ]; then
+	exit 0
+fi
+
+CLANG_FLAGS=$@
+NCPUS=${RPM_BUILD_NCPUS:-1}
+
+check_convert_bitcode () {
+  local file_name=$(realpath ${1})
+  local file_type=$(file ${file_name})
+
+  shift
+  CLANG_FLAGS="$@"
+
+  if [[ "${file_type}" == *"LLVM IR bitcode"* ]]; then
+    # Check the output of llvm-strings for the command line, which is in the LLVM bitcode because
+    # we pass -frecord-gcc-switches.
+    # Check for a line that has "-flto" after (or without) "-fno-lto".
+    llvm-strings ${file_name} | while read line ; do
+      flto=$(echo $line   | grep -o -b -e -flto     | tail -n 1 | cut -d : -f 1)
+      fnolto=$(echo $line | grep -o -b -e -fno-lto  | tail -n 1 | cut -d : -f 1)
+
+      if test -n "$flto" && { test -z "$fnolto" || test "$flto" -gt "$fnolto"; } ; then
+        echo "Compiling LLVM bitcode file ${file_name}."
+        clang ${CLANG_FLAGS} -fno-lto -Wno-unused-command-line-argument \
+          -x ir ${file_name} -c -o ${file_name}
+        break
+      fi
+      done
+  elif [[ "${file_type}" == *"current ar archive"* ]]; then
+    echo "Unpacking ar archive ${file_name} to check for LLVM bitcode components."
+    # create archive stage for objects
+    local archive_stage=$(mktemp -d)
+    local archive=${file_name}
+    pushd ${archive_stage}
+    ar x ${archive}
+    for archived_file in $(find -not -type d); do
+      check_convert_bitcode ${archived_file} ${CLANG_FLAGS}
+      echo "Repacking ${archived_file} into ${archive}."
+      ar r ${archive} ${archived_file}
+    done
+    popd
+  fi
+}
+
+echo "Checking for LLVM bitcode artifacts"
+export -f check_convert_bitcode
+find "$RPM_BUILD_ROOT" -type f -name "*.[ao]" -print0 | \
+  xargs -0 -r -n1 -P$NCPUS sh -c "check_convert_bitcode \$@ $CLANG_FLAGS" ARG0

macros

@@ -233,6 +233,8 @@ print(result)
 # __brp_mangle_shebangs_exclude_from_file - file from which to get files to ignore
 %__brp_mangle_shebangs /usr/lib/rpm/redhat/brp-mangle-shebangs %{?__brp_mangle_shebangs_exclude:--shebangs "%{?__brp_mangle_shebangs_exclude}"} %{?__brp_mangle_shebangs_exclude_file:--shebangs-from "%{__brp_mangle_shebangs_exclude_file}"} %{?__brp_mangle_shebangs_exclude_from:--files "%{?__brp_mangle_shebangs_exclude_from}"} %{?__brp_mangle_shebangs_exclude_from_file:--files-from "%{__brp_mangle_shebangs_exclude_from_file}"}
 
+%__brp_llvm_compile_lto_elf /usr/lib/rpm/redhat/brp-llvm-compile-lto-elf %{build_cflags} %{build_ldflags}
+
 %__os_install_post    \
     %{?__brp_ldconfig} \
     %{?__brp_compress} \
@@ -249,6 +251,7 @@ print(result)
 %{nil}
 
 %__spec_install_post\
+    %[ "%{toolchain}" == "clang" ? "%{?__brp_llvm_compile_lto_elf}" : "%{nil}" ] \
     %{?__debug_package:%{__debug_install_post}}\
     %{__arch_install_post}\
     %{__os_install_post}\

redhat-rpm-config.spec

@@ -6,7 +6,7 @@
 
 Summary: Red Hat specific rpm configuration files
 Name: redhat-rpm-config
-Version: 196
+Version: 197
 Release: 1%{?dist}
 # No version specified.
 License: GPL+
@@ -59,6 +59,9 @@ Source202: brp-python-bytecompile
 # https://github.com/fedora-python/marshalparser
 Source203: brp-fix-pyc-reproducibility
 
+# for converting llvm LTO bitcode objects into ELF
+Source204: brp-llvm-compile-lto-elf
+
 # Dependency generator scripts (deprecated)
 Source300: find-provides
 Source304: find-requires
@@ -213,6 +216,9 @@ install -p -m 644 -t %{buildroot}%{_rpmluadir}/fedora/srpm forge.lua
 %doc buildflags.md
 
 %changelog
+* Wed Sep 21 2022 Timm Bäder <tbaeder@redhat.com> - 197-1
+- Ship brp-llvm-compile-lto-elf script
+
 * Mon Jun 27 2022 Nick Clifton  <nickc@redhat.com> - 196-1
 - Pass "--remove section .gnu.build.attributes" to the find-debuginfo script.
 - Resolves: rhbz#2099613

tests/brp-llvm-compile-lto-elf/brp-llvm-compile-lto-elf-test-lib/brp-llvm-compile-lto-elf-test-lib.c

@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void hello(void) {
+    printf("Hello, world!\n");
+}

tests/brp-llvm-compile-lto-elf/brp-llvm-compile-lto-elf-test-lib/brp-llvm-compile-lto-elf-test-lib.h

@@ -0,0 +1 @@
+void hello(void);

tests/brp-llvm-compile-lto-elf/brp-llvm-compile-lto-elf-test-lib/brp-llvm-compile-lto-elf-test-lib.spec

@@ -0,0 +1,34 @@
+Name: brp-llvm-compile-lto-elf-test-lib
+Version: 1
+Release: 1
+Summary: Library package for testing brp-llvm-compile-lto-elf
+License: MIT
+
+BuildRequires: clang binutils
+Source0: %{name}.c
+Source1: %{name}.h
+
+# FIXME: I'm not sure why this doesn't work
+%undefine _package_note_file
+
+%global toolchain clang
+
+%description
+%{summary}
+
+%build
+
+clang ${CFLAGS} -c %{SOURCE0} -o lib.o
+ar cr %{name}.a lib.o
+ranlib %{name}.a
+
+%install
+mkdir -p %{buildroot}%{_libdir}
+mkdir -p %{buildroot}%{_includedir}
+
+%{__install} -p -m 644 -t %{buildroot}%{_libdir} %{name}.a
+%{__install} -p -m 644 -t %{buildroot}%{_includedir} %{SOURCE1}
+
+%files
+%{_libdir}/%{name}.a
+%{_includedir}/%{name}.h

tests/brp-llvm-compile-lto-elf/brp-llvm-compile-lto-elf-test/brp-llvm-compile-lto-elf-test.c

@@ -0,0 +1,6 @@
+#include <brp-llvm-compile-lto-elf-test-lib.h>
+
+int main(int argc, char **argv) {
+  hello();
+  return 0;
+}

tests/brp-llvm-compile-lto-elf/brp-llvm-compile-lto-elf-test/brp-llvm-compile-lto-elf-test.spec

@@ -0,0 +1,24 @@
+Name: brp-llvm-compile-lto-elf-test
+Version: 1
+Release: 1
+Summary: Library package for testing brp-llvm-compile-lto-elf
+License: MIT
+
+BuildRequires: gcc
+BuildRequires: brp-llvm-compile-lto-elf-test-lib
+
+Source0: %{name}.c
+
+# FIXME: I'm not sure why this doesn't work
+%undefine _package_note_file
+
+
+%description
+%{summary}
+
+%build
+gcc ${CFLAGS} -c %{SOURCE0} -o %{name}.o
+gcc ${LDFLAGS} %{name}.o %{_libdir}/%{name}-lib.a -o %{name}
+
+%check
+./%{name} | grep "Hello, world!"

tests/brp-llvm-compile-lto-elf/main.fmf

@@ -0,0 +1,8 @@
+Summary: Test that the brp-llvm-compile-lto-elf script is working correctly
+
+require:
+  - dnf-plugins-core
+  - redhat-rpm-config
+  - rpm-build
+
+test: ./runtest.sh

tests/brp-llvm-compile-lto-elf/runtest.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -ex
+
+lib_dir=brp-llvm-compile-lto-elf-test-lib
+lib_spec=$lib_dir/brp-llvm-compile-lto-elf-test-lib.spec
+
+dnf -y build-dep $lib_spec 
+rpmbuild --define "_sourcedir ." --define "_builddir ./$lib_dir" --define "_rpmdir ."  -bb $lib_spec
+
+dnf -y install ./`rpm --eval '%{_arch}'`/*.rpm
+
+test_dir=brp-llvm-compile-lto-elf-test
+test_spec=$test_dir/brp-llvm-compile-lto-elf-test.spec
+
+dnf -y build-dep $test_spec
+rpmbuild --define "_sourcedir ." --define "_builddir ./$test_dir" -bi $test_spec