Add initial support for i386 builds

infra/base-images/base-builder/Dockerfile

@@ -16,7 +16,16 @@
 
 FROM gcr.io/oss-fuzz-base/base-clang
 MAINTAINER mike.aizatsky@gmail.com
-RUN apt-get install -y git subversion jq python3 zip make libunwind8-dev binutils-dev libblocksruntime-dev
+RUN apt-get install -y git \
+    subversion \
+    jq \
+    python3 \
+    zip \
+    make \
+    libunwind8-dev \
+    binutils-dev \
+    libblocksruntime-dev \
+    libc6-dev-i386
 
 # Default build flags for various sanitizers.
 ENV SANITIZER_FLAGS_address "-fsanitize=address -fsanitize-address-use-after-scope"
@@ -42,9 +51,10 @@ ENV COVERAGE_FLAGS="-fsanitize=fuzzer-no-link"
 # messages which are treated as errors by some projects.
 ENV COVERAGE_FLAGS_coverage "-fprofile-instr-generate -fcoverage-mapping -pthread -Wl,--no-as-needed -Wl,-ldl -Wl,-lm -Wno-unused-command-line-argument"
 
-# Default sanitizer and fuzzing engine to use.
+# Default sanitizer, fuzzing engine and architecture to use.
 ENV SANITIZER="address"
 ENV FUZZING_ENGINE="libfuzzer"
+ENV ARCHITECTURE="x86_64"
 
 # DEPRECATED - NEW CODE SHOULD NOT USE THIS. OLD CODE SHOULD STOP. Please use
 # LIB_FUZZING_ENGINE instead.

infra/base-images/base-builder/compile

@@ -22,6 +22,10 @@ if [ -z "${SANITIZER_FLAGS-}" ]; then
   export SANITIZER_FLAGS=${!FLAGS_VAR-}
 fi
 
+if [[ $ARCHITECTURE == "i386" ]]; then
+    export CFLAGS="-m32 $CFLAGS"
+    export CXXFLAGS_EXTRA="-L/usr/i386/lib $CXXFLAGS_EXTRA"
+fi
 if [[ $FUZZING_ENGINE != "none" ]]; then
   # compile script might override environment, use . to call it.
   . compile_${FUZZING_ENGINE}

infra/base-images/base-clang/checkout_build_install_llvm.sh

@@ -15,7 +15,7 @@
 #
 ################################################################################
 
-LLVM_DEP_PACKAGES="build-essential make cmake ninja-build git subversion python2.7"
+LLVM_DEP_PACKAGES="build-essential make cmake ninja-build git subversion python2.7 g++-multilib"
 apt-get install -y $LLVM_DEP_PACKAGES
 
 # Checkout
@@ -99,6 +99,20 @@ ninja
 ninja install
 rm -rf $WORK/llvm-stage1 $WORK/llvm-stage2
 
+mkdir -p $WORK/i386
+cd $WORK/i386
+cmake -G "Ninja" \
+      -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \
+      -DCMAKE_INSTALL_PREFIX=/usr/i386/ -DLIBCXX_ENABLE_SHARED=OFF \
+      -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON -DCMAKE_BUILD_TYPE=Release \
+      -DCMAKE_C_FLAGS="-m32" -DCMAKE_CXX_FLAGS="-m32" \
+      -DLLVM_TARGETS_TO_BUILD="$TARGET_TO_BUILD" \
+      $SRC/llvm
+
+ninja cxx
+ninja install-cxx
+rm -rf $WORK/i386
+
 mkdir -p $WORK/msan
 cd $WORK/msan
 

infra/base-images/base-runner/Dockerfile

@@ -22,6 +22,7 @@ RUN apt-get install -y \
     fonts-dejavu \
     git \
     libblocksruntime0 \
+    libc6-dev-i386 \
     libcap2 \
     libunwind8 \
     python3 \

infra/helper.py

@@ -78,6 +78,7 @@ def main():
 
   build_fuzzers_parser = subparsers.add_parser(
       'build_fuzzers', help='Build fuzzers for a project.')
+  _add_architecture_args(build_fuzzers_parser)
   _add_engine_args(build_fuzzers_parser)
   _add_sanitizer_args(build_fuzzers_parser)
   _add_environment_args(build_fuzzers_parser)
@@ -95,6 +96,7 @@ def main():
 
   check_build_parser = subparsers.add_parser(
       'check_build', help='Checks that fuzzers execute without errors.')
+  _add_architecture_args(check_build_parser)
   _add_engine_args(check_build_parser, choices=['libfuzzer', 'afl'])
   _add_sanitizer_args(
       check_build_parser, choices=['address', 'memory', 'undefined'])
@@ -149,6 +151,7 @@ def main():
   shell_parser = subparsers.add_parser(
       'shell', help='Run /bin/bash within the builder container.')
   shell_parser.add_argument('project_name', help='name of the project')
+  _add_architecture_args(shell_parser)
   _add_engine_args(shell_parser)
   _add_sanitizer_args(shell_parser)
   _add_environment_args(shell_parser)
@@ -249,6 +252,11 @@ def _get_work_dir(project_name=''):
   return os.path.join(BUILD_DIR, 'work', project_name)
 
 
+def _add_architecture_args(parser, choices=('x86_64', 'i386')):
+  """Add common architecture args."""
+  parser.add_argument('--architecture', default='x86_64', choices=choices)
+
+
 def _add_engine_args(
         parser,
         choices=('libfuzzer', 'afl', 'honggfuzz', 'dataflow', 'none')):
@@ -416,7 +424,8 @@ def build_fuzzers(args):
 
   env = [
       'FUZZING_ENGINE=' + args.engine,
-      'SANITIZER=' + args.sanitizer
+      'SANITIZER=' + args.sanitizer,
+      'ARCHITECTURE=' + args.architecture
   ]
   if args.e:
     env += args.e

infra/travis/travis_build.py

@@ -23,7 +23,6 @@
 import subprocess
 import yaml
 
-
 DEFAULT_FUZZING_ENGINES = ['afl', 'libfuzzer']
 DEFAULT_SANITIZERS = ['address', 'undefined']
 
@@ -54,11 +53,13 @@ def execute_helper_command(helper_command):
   subprocess.check_call(command)
 
 
-def build_fuzzers(project, sanitizer, engine):
+def build_fuzzers(project, sanitizer, engine, architecture='x86_64'):
   """Execute helper.py's build_fuzzers command on |project|. Build the fuzzers
   with |sanitizer| and |engine|."""
-  execute_helper_command(
-      ['build_fuzzers', project, '--engine', engine, '--sanitizer', sanitizer])
+  execute_helper_command([
+      'build_fuzzers', project, '--engine', engine, '--sanitizer', sanitizer,
+      '--architecture', architecture
+  ])
 
 
 def check_build(project, sanitizer, engine):
@@ -97,6 +98,11 @@ def build_project(project):
     build_fuzzers(project, sanitizer, 'libfuzzer')
     check_build(project, sanitizer, 'libfuzzer')
 
+  if 'i386' in project_yaml.get('architectures', []):
+    # i386 builds always use libFuzzer and ASAN.
+    build_fuzzers(project, 'address', 'libfuzzer', 'i386')
+    check_build(project, 'address', 'libfuzzer')
+
 
 def main():
   projects = get_modified_projects()
@@ -111,5 +117,6 @@ def main():
     print('Failed projects:', ' '.join(failed_projects))
     exit(1)
 
+
 if __name__ == '__main__':
   main()