initial oss-fuzz compatible version

CMakeLists.txt

@@ -41,6 +41,7 @@ option(FMT_WERROR "Halt the compilation with an error on compiler warnings."
 option(FMT_DOC "Generate the doc target." ${MASTER_PROJECT})
 option(FMT_INSTALL "Generate the install target." ${MASTER_PROJECT})
 option(FMT_TEST "Generate the test target." ${MASTER_PROJECT})
+option(FMT_FUZZ "Generate the fuzz target." ${MASTER_PROJECT})
 
 project(FMT CXX)
 
@@ -261,6 +262,10 @@ if (FMT_TEST)
   add_subdirectory(test)
 endif ()
 
+if (FMT_FUZZ)
+  add_subdirectory(fuzzing)
+endif ()
+
 set(gitignore ${PROJECT_SOURCE_DIR}/.gitignore)
 if (MASTER_PROJECT AND EXISTS ${gitignore})
   # Get the list of ignored files from .gitignore.

fuzzing/.gitignore

@@ -0,0 +1 @@
+build-*/

fuzzing/CMakeLists.txt

@@ -4,37 +4,42 @@
 # https://www.pauldreik.se/
 
 
-cmake_minimum_required(VERSION 3.10)
+#cmake_minimum_required(VERSION 3.10)
 
-project(fmt_fuzzers LANGUAGES CXX)
+#project(fmt_fuzzers LANGUAGES CXX)
 
-add_definitions(-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1)
+#add_definitions(-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1)
 
-add_subdirectory(fmt)
+#add_subdirectory(fmt)
 
 
 # settings this links in a main. useful for reproducing,
 # kcov, gdb, afl, valgrind.
 # (note that libFuzzer can also reproduce, just pass it the files)
-option(reproduce_mode "enables the reproduce mode, instead of libFuzzer" On)
+option(FMT_FUZZ_LINKMAIN "enables the reproduce mode, instead of libFuzzer" On)
+
+#for oss-fuzz - insert $LIB_FUZZING_ENGINE into the link flags, but only for
+#the fuzz targets, otherwise the cmake configuration step fails.
+option(FMT_FUZZ_LDFLAGS "LDFLAGS for the fuzz targets" "")
 
 #find all fuzzers.
-file(GLOB SOURCES "fuzz*.cpp")
+file(GLOB SOURCES "*.cpp")
 
-if(reproduce_mode)
-  set(prefix reproducer_)
+if(FMT_FUZZ_LINKMAIN)
   add_definitions(-DIMPLEMENT_MAIN=1)
-else()
-  # this assumes clang is used
-  string(APPEND CMAKE_CXX_FLAGS " -fsanitize=fuzzer")
-  set(prefix fuzzer_)
 endif()
 
+
+
 macro(implement_fuzzer sourcefile)
   get_filename_component(basename ${sourcefile} NAME_WE)
-  add_executable(${prefix}${basename} ${sourcefile})
-  target_link_libraries(${prefix}${basename}  PRIVATE fmt)
-  set_property(TARGET ${prefix}${basename} PROPERTY CXX_STANDARD 17)
+  set(name fuzzer_${basename})
+  add_executable(${name} ${sourcefile})
+  target_link_libraries(${name}  PRIVATE fmt)
+if(FMT_FUZZ_LDFLAGS)
+  target_link_libraries(${name} PRIVATE ${FMT_FUZZ_LDFLAGS})
+endif()
+  set_property(TARGET ${name} PROPERTY CXX_STANDARD 17)
 endmacro()
 
 foreach(X IN ITEMS ${SOURCES})

fuzzing/build.sh

@@ -0,0 +1,57 @@
+#!/bin/sh
+#
+#
+set -e
+me=$(basename $0)
+root=$(readlink -f "$(dirname "$0")/..")
+
+
+echo $me: root=$root
+
+here=$(pwd)
+
+#builds the fuzzers as one would do if using afl or just making
+#binaries for reproducing.
+builddir=$here/build-fuzzers-reproduce
+mkdir -p $builddir
+cd $builddir
+CXX="ccache g++" CXXFLAGS="-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1" cmake \
+$root -GNinja -DCMAKE_BUILD_TYPE=Debug -DFMT_DOC=Off -DFMT_TEST=Off -DFMT_FUZZ=On
+cmake --build $builddir
+
+
+
+#builds the fuzzers as oss-fuzz does
+builddir=$here/build-fuzzers-ossfuzz
+mkdir -p $builddir
+cd $builddir
+CXX="clang++" \
+CXXFLAGS="-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1 -fsanitize=fuzzer-no-link" \
+cmake $root -GNinja -DCMAKE_BUILD_TYPE=Debug \
+-DFMT_DOC=Off \
+-DFMT_TEST=Off \
+-DFMT_FUZZ=On \
+-DFMT_FUZZ_LINKMAIN=Off \
+-DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer"
+
+cmake --build $builddir
+
+
+#builds fuzzers for local fuzzing with libfuzzer
+builddir=$here/build-fuzzers-libfuzzer
+mkdir -p $builddir
+cd $builddir
+CXX="clang++" \
+CXXFLAGS="-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1 -fsanitize=fuzzer-no-link,address,undefined" \
+cmake $root -GNinja -DCMAKE_BUILD_TYPE=Debug \
+-DFMT_DOC=Off \
+-DFMT_TEST=Off \
+-DFMT_FUZZ=On \
+-DFMT_FUZZ_LINKMAIN=Off \
+-DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer"
+
+cmake --build $builddir
+
+
+echo $me: all good
+