Install 32-bit dependencies in the 32-bit build environment.

Author: cmeister2

scripts/32bitdeps.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+#
+# This script is called in a 32-bit build environment to install necessary
+# dependencies.
+
+set -ex
+
+# Work out if we need to install with sudo or not.
+if [[ $(id -u) -eq 0 ]]
+then
+  # We are root, so we can install without sudo.
+  echo "Running as root, no sudo required."
+  export SUDO=""
+else
+  # We are not root, so we need to use sudo.
+  echo "Running as non-root, using sudo."
+  export SUDO="sudo"
+fi
+
+# Download dependencies for oss-fuzz
+$SUDO dpkg --add-architecture i386
+$SUDO apt-get -o Dpkg::Use-Pty=0 update
+$SUDO apt-get -o Dpkg::Use-Pty=0 install -y \
+  protobuf-compiler:i386 \
+  libprotobuf-dev:i386 \
+  libstdc++-9-dev:i386

scripts/compile_target.sh

@@ -31,6 +31,12 @@ export BUILD_ROOT; BUILD_ROOT=$(readlink -f "${SCRIPTDIR}/..")
 # shellcheck source=stdlib_flag_utils.sh
 source "${SCRIPTDIR}/stdlib_flag_utils.sh"
 
+# Install any 32-bit dependencies if building for 32-bit.
+if [[ "${ARCHITECTURE:-}" == "i386" ]]
+then
+  "${SCRIPTDIR}/32bitdeps.sh"
+fi
+
 # Check for GDB-specific behaviour by checking for the GDBMODE flag.
 # - Compile with -O0 so that DEBUGASSERTs can be debugged in gdb.
 if [[ -n ${GDBMODE:-} ]]