fuzzing: oss-fuzz build script

Script that will be executed by oss-fuzz to build fuzzing targets
and dependencies

fuzzing/build-oss-fuzz.sh

@@ -0,0 +1,161 @@
+#!/bin/bash -eu
+
+# build-oss-fuzz.sh
+#
+# Build script which is executed by oss-fuzz build.sh
+#
+# $SRC: location of code checkouts
+# $OUT: location to put fuzzing targets and corpus
+# $WORK: writable directory where all compilation should be executed
+#
+# /!\ Do not override any CC, CXX, CFLAGS, ... variables
+#
+
+# This script is divided in two parts
+#
+# 1) Build all the dependencies statically
+#
+# 2) Build the fuzzing targets
+
+# Prefix where we will temporarily install everything
+PREFIX=$WORK/prefix
+mkdir -p $PREFIX
+export PKG_CONFIG_PATH=$PREFIX/lib/pkgconfig
+export PATH=$PREFIX/bin:$PATH
+
+# Minimize gst-debug level/code
+export CFLAGS="$CFLAGS -DGST_LEVEL_MAX=2"
+
+#
+echo "CFLAGS : " $CFLAGS
+echo "CXXFLAGS : " $CXXFLAGS
+PLUGIN_DIR=$PREFIX/lib/gstreamer-1.0
+
+# Switch to work directory
+cd $WORK
+
+# 1) BUILD GLIB AND GSTREAMER
+# Note: we build glib ourselves so that we get proper malloc/free backtraces
+tar xvJf $SRC/glib-2.54.2.tar.xz
+cd glib-2.54.2
+./configure --prefix=$PREFIX --enable-static --disable-shared --disable-libmount --with-pcre=internal && make -j$(nproc) && make install
+cd ..
+
+# Note: We don't use/build orc since it still seems to be problematic
+# with clang and the various sanitizers.
+
+# For now we only build core and base. Add other modules when/if needed
+for i in gstreamer gst-plugins-base;
+do
+    mkdir -p $i
+    cd $i
+    $SRC/$i/autogen.sh --prefix=$PREFIX --disable-shared --enable-static --disable-examples \
+		       --disable-gtk-doc --disable-introspection --enable-static-plugins \
+		       --disable-gst-tracer-hooks --disable-registry
+    make -j$(nproc)
+    make install
+    cd ..
+done
+
+
+
+# 2) Build the target fuzzers
+
+# All targets will be linked in with $LIB_FUZZING_ENGINE which contains the
+# actual fuzzing runner. Anything fuzzing engine can be used provided it calls
+# the same function as libfuzzer.
+
+# Note: The fuzzer .o needs to be first compiled with CC and then linked with CXX
+
+# We want to statically link everything, except for shared libraries
+# that are present on the base image. Those need to be specified
+# beforehand and explicitely linked dynamically If any of the static
+# dependencies require a pre-installed shared library, you need to add
+# that library to the following list
+PREDEPS_LDFLAGS="-Wl,-Bdynamic -ldl -lm -pthread -lrt -lpthread"
+
+# These are the basic .pc dependencies required to build any of the fuzzing targets
+# That is : glib, gstreamer core and gst-app
+# The extra target-specific dependencies are to be specified later
+COMMON_DEPS="glib-2.0 gstreamer-1.0 gstreamer-app-1.0"
+
+# For each target, defined the following:
+# TARGET_DEPS : Extra .pc dependencies for the target (in addition to $COMMON_DEPS)
+#               All dependencies (including sub-dependencies) must be speecified
+# PLUGINS : .a of the plugins to link
+#           They must match the static plugins declared/registered in the target
+
+#
+# TARGET : push-based ogg/theora/vorbis discoverer
+#
+# FIXME : Rename to discoverer_push_oggtheoravorbis
+
+TARGET_DEPS=" gstreamer-pbutils-1.0 \
+	      gstreamer-video-1.0 \
+	      gstreamer-audio-1.0 \
+	      gstreamer-riff-1.0 \
+	      gstreamer-tag-1.0 \
+	      zlib ogg vorbis vorbisenc \
+	      theoraenc theoradec theora"
+
+PLUGINS="$PLUGIN_DIR/libgstcoreelements.a \
+       $PLUGIN_DIR/libgsttypefindfunctions.a \
+       $PLUGIN_DIR/libgstplayback.a \
+       $PLUGIN_DIR/libgstapp.a \
+       $PLUGIN_DIR/libgstvorbis.a \
+       $PLUGIN_DIR/libgsttheora.a \
+       $PLUGIN_DIR/libgstogg.a"
+
+echo
+echo ">>>> BUILDING gst-discoverer.o"
+echo
+BUILD_CFLAGS="$CFLAGS `pkg-config --static --cflags $COMMON_DEPS $TARGET_DEPS`"
+BUILD_LDFLAGS="-Wl,-static `pkg-config --static --libs $COMMON_DEPS $TARGET_DEPS`"
+
+$CC $CFLAGS $BUILD_CFLAGS -c $SRC/gst-ci/fuzzing/gst-discoverer.c -o $SRC/gst-ci/fuzzing/gst-discoverer.o
+$CXX $CXXFLAGS \
+      -o $OUT/gst-discoverer \
+      $PREDEPS_LDFLAGS \
+      $SRC/gst-ci/fuzzing/gst-discoverer.o \
+      $PLUGINS \
+      $BUILD_LDFLAGS \
+      $LIB_FUZZING_ENGINE \
+      -Wl,-Bdynamic
+
+#
+# TARGET : push-based typefind
+#
+
+# typefindfunction depends on pbutils which depends on gst{audio|video|tag}
+TARGET_DEPS=" gstreamer-pbutils-1.0 \
+	      gstreamer-video-1.0 \
+	      gstreamer-audio-1.0 \
+	      gstreamer-tag-1.0"
+
+PLUGINS="$PLUGIN_DIR/libgstcoreelements.a \
+       $PLUGIN_DIR/libgsttypefindfunctions.a \
+       $PLUGIN_DIR/libgstapp.a"
+
+echo
+echo ">>>> BUILDING gst-discoverer.o"
+echo
+BUILD_CFLAGS="$CFLAGS `pkg-config --static --cflags $COMMON_DEPS $TARGET_DEPS`"
+BUILD_LDFLAGS="-Wl,-static `pkg-config --static --libs $COMMON_DEPS $TARGET_DEPS`"
+
+$CC $CFLAGS $BUILD_CFLAGS -c $SRC/gst-ci/fuzzing/typefind.c -o $SRC/gst-ci/fuzzing/typefind.o
+$CXX $CXXFLAGS \
+      -o $OUT/typefind \
+      $PREDEPS_LDFLAGS \
+      $SRC/gst-ci/fuzzing/typefind.o \
+      $PLUGINS \
+      $BUILD_LDFLAGS \
+      $LIB_FUZZING_ENGINE \
+      -Wl,-Bdynamic
+
+echo
+echo ">>>> Installing seed corpus"
+echo
+# FIXME : Sadly we apparently need to have the corpus downloaded in the
+#         Dockerfile and not here.
+
+cp $SRC/*_seed_corpus.zip $OUT