Migrate the pffft sandbox to contrib/

PiperOrigin-RevId: 427443359
Change-Id: I852a818ae302a86abe32a2820f349f67861e342e

contrib/CMakeLists.txt

@@ -16,6 +16,7 @@
 set(SAPI_CONTRIB_SANDBOXES
   hunspell
   jsonnet
+  pffft
   zopfli
   zstd
 )

contrib/README.md

@@ -6,9 +6,10 @@ libraries.
 ## Projects Sandboxed
 
 Directory   | Project                                           | Home Page                                                                    | Integration
------------ | ------------------------------------------------- | -------------------------------------------------------------------- | -----------
-`jsonnet/`  | Jsonnet - The Data Templating Language            | [github.com/google/jsonnet](https://github.com/google/jsonnet)       | CMake
+----------- | ------------------------------------------------- | ---------------------------------------------------------------------------- | -----------
 `hunspell/` | Hunspell - The most popular spellchecking library | [github.com/hunspell/hunspell](https://github.com/hunspell/hunspell)         | CMake
+`jsonnet/`  | Jsonnet - The Data Templating Language            | [github.com/google/jsonnet](https://github.com/google/jsonnet)               | CMake
+`pffft/`    | PFFFT - a pretty fast Fourier Transform           | [bitbucket.org/jpommier/pffft.git](https://bitbucket.org/jpommier/pffft.git) | CMake
 `zopfli`    | Zopfli - Compression Algorithm                    | [github.com/google/zopfli](https://github.com/google/zopfli)                 | CMake
 `zstd/`     | Zstandard - Fast real-time compression algorithm  | [github.com/facebook/zstd](https://github.com/facebook/zstd)                 | CMake
 

contrib/pffft/CMakeLists.txt

@@ -12,50 +12,48 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-cmake_minimum_required(VERSION 3.10)
-
+cmake_minimum_required(VERSION 3.13..3.22)
 project(pffft CXX C)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 
+if(NOT TARGET sapi::sapi)
+  set(SAPI_ROOT "../.." CACHE PATH "Path to the Sandboxed API source tree")
+  add_subdirectory("${SAPI_ROOT}"
+                   "${CMAKE_BINARY_DIR}/sandboxed-api-build"
+                   EXCLUDE_FROM_ALL)
+endif()
+
+include(CheckLibraryExists)
+
+FetchContent_Declare(pffft
+  GIT_REPOSITORY https://bitbucket.org/jpommier/pffft.git
+  GIT_TAG        988259a41d1522047a9420e6265a6ba8289c1654 # 2021-12-02
+)
+FetchContent_MakeAvailable(pffft)
+
 add_library(pffft STATIC
-  master/pffft.c
-  master/pffft.h
-  master/fftpack.c
-  master/fftpack.h
+  "${pffft_SOURCE_DIR}/pffft.c"
+  "${pffft_SOURCE_DIR}/pffft.h"
+  "${pffft_SOURCE_DIR}/fftpack.c"
+  "${pffft_SOURCE_DIR}/fftpack.h"
 )
 
 add_executable(pffft_main
-  master/test_pffft.c
+  "${pffft_SOURCE_DIR}/test_pffft.c"
 )
-
 target_link_libraries(pffft_main PRIVATE
   pffft
 )
 
-set(MATH_LIBS "")
-include(CheckLibraryExists)
-check_library_exists(m sin "" LIBM)
-if(LIBM)
-  list(APPEND MATH_LIBS "m")
+check_library_exists(m sin "" _sapi_HAVE_LIBM)
+if(_sapi_HAVE_LIBM)
+  target_link_libraries(pffft PUBLIC
+    m
+  )
 endif()
 
-target_link_libraries(pffft PUBLIC ${MATH_LIBS})
-
-# Adding dependencies
-set(SAPI_ROOT "../.." CACHE PATH "Path to the Sandboxed API source tree")
-# Then configure:
-#   mkdir -p build && cd build
-#   cmake .. -G Ninja -DSAPI_ROOT=$HOME/sapi_root
-
-set(SAPI_ENABLE_EXAMPLES OFF CACHE BOOL "")
-set(SAPI_ENABLE_TESTS OFF CACHE BOOL "")
-add_subdirectory("${SAPI_ROOT}"
-                 "${CMAKE_BINARY_DIR}/sandboxed-api-build"
-                 # Omit this to have the full Sandboxed API in IDE
-                 EXCLUDE_FROM_ALL)
-
 add_sapi_library(pffft_sapi
   FUNCTIONS pffft_new_setup
             pffft_destroy_setup
@@ -83,22 +81,23 @@ add_sapi_library(pffft_sapi
             sinti
             sint
 
-  INPUTS master/pffft.h master/fftpack.h
+  INPUTS "${pffft_SOURCE_DIR}/pffft.h"
+         "${pffft_SOURCE_DIR}/fftpack.h"
   LIBRARY pffft
   LIBRARY_NAME Pffft
 
   NAMESPACE ""
 )
-
+add_library(sapi_contrib::pffft ALIAS pffft_sapi)
 target_include_directories(pffft_sapi INTERFACE
   "${PROJECT_BINARY_DIR}"
+  "${SAPI_SOURCE_DIR}"
 )
 
 add_executable(pffft_sandboxed
   main_pffft_sandboxed.cc
 )
-
 target_link_libraries(pffft_sandboxed PRIVATE
-  pffft_sapi
+  sapi_contrib::pffft
   sapi::sapi
 )

contrib/pffft/README.md

@@ -1,16 +1,35 @@
 # Sandboxing PFFFT library
 
+This library was sandboxed as part of Google's summer 2020 internship program
+([blog post](https://security.googleblog.com/2020/12/improving-open-source-security-during.html)).
+
 Build System: CMake
 OS: Linux
 
-### Check out the PFFFT library & CMake set up
-```
-git submodule update --init --recursive
+### How to use from an existing Project
 
-mkdir -p build && cd build
-cmake .. -G Ninja -DPFFFT_ROOT_DIR=$PWD
-ninjas
+If your project does not include Sandboxed API as a dependency yet, add the
+following lines to the main `CMakeLists.txt`:
+
+```cmake
+include(FetchContent)
+
+FetchContent_Declare(sandboxed-api
+  GIT_REPOSITORY https://github.com/google/sandboxed-api
+  GIT_TAG        main  # Or pin a specific commit/tag
+)
+FetchContent_MakeAvailable(sandboxed-api)  # CMake 3.14 or higher
+
+add_sapi_subdirectory(contrib/pffft)
 ```
+
+The `add_sapi_subdirectory()` macro sets up the source and binary directories
+for the sandboxed jsonnet targets.
+
+Afterwards your project's code can link to `sapi_contrib::pffft` and use the
+generated header `pffft_sapi.sapi.h`. An example sandbox policy can be found
+in `main_pffft_sandboxed.cc`.
+
 ### For testing:
 `cd build`, then `./pffft_sandboxed`
 
@@ -19,14 +38,15 @@ display custom info with
 `./pffft_sandboxed --logtostderr`
 
 ## ***About the project***
-*PFFFT library is concerned with 1D Fast-Fourier Transformations finding a
+
+PFFFT library is concerned with 1D Fast-Fourier Transformations finding a
 compromise between accuracy and speed. It deals with real and complex
 vectors, both cases being illustrated in the testing part (`test_pffft.c`
 for initially and original version, `main_pffft_sandboxed.cc` for our
 currently implemented sandboxed version).
 The original files can be found at: https://bitbucket.org/jpommier/pffft/src.*
 
-*The purpose of sandboxing is to limit the permissions and capabilities of
+The purpose of sandboxing is to limit the permissions and capabilities of
 library’s methods, in order to secure the usage of them.
 After obtaining the sandbox, the functions will be called through an
 Sandbox API (being called `api` in the current test) and so, the
@@ -50,10 +70,12 @@ Without using this type of argument when running, the output format is set
 by default.*
 
 #### CMake observations resume:
+
 * linking pffft and fftpack (which contains necessary functions for pffft)
 * set math library
 
 #### Sandboxed main observations resume:
+
 * containing two testing parts (fft / pffft benchmarks)
 * showing the performance of the transformations implies
   testing them through various FFT dimenstions.

contrib/pffft/main_pffft_sandboxed.cc

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <gflags/gflags.h>
+#include <syscall.h>
 
 #include <cmath>
 #include <cstdio>
@@ -21,6 +21,7 @@
 #include <ctime>
 
 #include <glog/logging.h>
+#include "gflags/gflags.h"
 #include "pffft_sapi.sapi.h"  // NOLINT(build/include)
 #include "sandboxed_api/util/flag.h"
 #include "sandboxed_api/vars.h"

oss-internship-2020/pffft/.gitignore

@@ -1,3 +0,0 @@
-*.o
-*.a
-pffft_main