MONGOCRYPT-535 Support libdfp as a Decimal128 abstraction

CMakeLists.txt

@@ -90,6 +90,7 @@ set (MONGOCRYPT_SOURCES
    src/crypto/libcrypto.c
    src/crypto/none.c
    src/mc-array.c
+   src/mc-dec128.c
    src/mc-efc.c
    src/mc-fle2-find-range-payload.c
    src/mc-fle2-insert-update-payload.c
@@ -282,7 +283,7 @@ target_link_libraries (
       kms_message_static
       $<BUILD_INTERFACE:mongo::mlib>
    PUBLIC
-      mongocrypt::intel_dfp
+      mongocrypt::dfp
       ${CMAKE_DL_LIBS}
    )
 
@@ -340,7 +341,7 @@ target_link_libraries (
       kms_message_static
       $<BUILD_INTERFACE:mongo::mlib>
    PUBLIC
-      mongocrypt::intel_dfp
+      mongocrypt::dfp
       ${CMAKE_THREAD_LIBS_INIT}
       ${CMAKE_DL_LIBS}
    )
@@ -360,7 +361,7 @@ if (ENABLE_BUILD_FOR_PPA)
    set (PKG_CONFIG_STATIC_LIBS "${PKG_CONFIG_STATIC_LIBS} -pthread")
 endif ()
 if (MONGOCRYPT_DFP_DIR STREQUAL "USE-SYSTEM")
-   get_property (SYSTEM_DFP_LOC TARGET intel_dfp PROPERTY IMPORTED_LOCATION)
+   get_property (SYSTEM_DFP_LOC TARGET _mongocrypt::system-dfp PROPERTY IMPORTED_LOCATION)
    set (PKG_CONFIG_STATIC_LIBS "${PKG_CONFIG_STATIC_LIBS} ${SYSTEM_DFP_LOC}")
 endif ()
 
@@ -521,7 +522,7 @@ add_test (
 
 foreach (test IN ITEMS path str)
    add_executable (mlib.${test}.test src/mlib/${test}.test.c)
-   add_test (mlib.${test} mlib.${test}.test)
+   add_test (NAME mlib.${test} COMMAND mlib.${test}.test)
    target_link_libraries (mlib.${test}.test PRIVATE mongo::mlib)
 endforeach ()
 
@@ -539,13 +540,13 @@ if ("cxx_relaxed_constexpr" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
       add_executable ("${exe_name}" "${file}")
       target_compile_features ("${exe_name}" PRIVATE cxx_relaxed_constexpr)
       target_link_libraries ("${exe_name}" PRIVATE
-         mongocrypt
+         mongocrypt_static
          mongo::mlib
-         mongocrypt::intel_dfp
+         mongocrypt::dfp
          Threads::Threads
          _mongocrypt::libbson_for_static
          )
-      add_test ("${test_name}" "${exe_name}")
+      add_test (NAME "${test_name}" COMMAND "${exe_name}")
    endforeach ()
 endif ()
 
@@ -636,10 +637,6 @@ if (ENABLE_BUILD_FOR_PPA)
    endif ()
    set (PKG_CONFIG_LIBS "${PKG_CONFIG_LIBS} -pthread")
 endif ()
-if (MONGOCRYPT_DFP_DIR STREQUAL "USE-SYSTEM")
-   get_property (SYSTEM_DFP_LOC TARGET intel_dfp PROPERTY IMPORTED_LOCATION)
-   set (PKG_CONFIG_LIBS "${PKG_CONFIG_LIBS} ${SYSTEM_DFP_LOC}")
-endif ()
 set (PKG_CONFIG_CFLAGS "-I\${includedir}")
 set (PKG_CONFIG_STATIC_CFLAGS "${PKG_CONFIG_CFLAGS} -DMONGOCRYPT_STATIC_DEFINE -DKMS_MSG_STATIC")
 configure_file (

Earthfile

@@ -253,7 +253,7 @@ rpm-build:
     GIT CLONE https://src.fedoraproject.org/rpms/libmongocrypt.git /R
     # Install the packages listed by "BuildRequires" and rpm-build:
     RUN __install $(awk '/^BuildRequires:/ { print $2 }' /R/libmongocrypt.spec) \
-                  rpm-build
+                  rpm-build libdfp-devel
     DO +COPY_SOURCE
     RUN cp -r /s/libmongocrypt/. /R
     RUN awk -f /R/etc/rpm/tweak.awk < /R/libmongocrypt.spec > /R/libmongocrypt.2.spec
@@ -300,7 +300,7 @@ deb-build:
     ARG env=deb-unstable
     FROM +env.$env
     RUN __install git-buildpackage fakeroot debhelper cmake libbson-dev \
-                  libintelrdfpmath-dev
+                  libdfp-dev quilt
     DO +COPY_SOURCE
     WORKDIR /s/libmongocrypt
     RUN git clean -fdx && git reset --hard

cmake/ImportDFP.cmake

@@ -2,67 +2,104 @@
    This file handles importing the DFP (decimal floating point) library for decimal128 support. It
    is patterned after ImportBSON in this same directory.
 
-   Initially, the only supported DFP implementation is Intel DFP. However, this module will allow
-   for the future addition of support for libdfp.
-
-   This file defines, exports, and installs one INTERFACE target: mongocrypt::intel_dfp.
+   This file defines, exports, and installs one INTERFACE target: _mongocrypt::dfp.
 
    The target(s) from this file are used to link the DFP library correctly for the build
    configuration of libmongocrypt. At find_package() time, we can resolve these interface targets
    to link to the DFP library based on the build configurations of libmongocrypt.
 
    In the initial implementation both mongo::mongocrypt and mongo::mongocrypt_static must link to
-   mongocrypt::intel_dfp (this is because if we link to the Intel DFP which is vendored with
+   _mongocrypt::dfp (this is because if we link to the Intel DFP which is vendored with
    libmongocrypt then we will link the object files directly and if we use the system Intel DFP then
    we will be linking with .a static library archives).
 
    The default behavior is to use the Intel DFP which is vendored in this repository. By setting
-   MONGOCRYPT_DFP_DIR=USE-SYSTEM the build will assume that an appropriate Intel DFP implementation
+   MONGOCRYPT_DFP_DIR=USE-SYSTEM the build will assume that an appropriate DFP implementation
    can be found in a location where it has been installed system-wide (most likely under /usr or
-   /usr/local).
+   /usr/local). It will search for an installation of IntelDFP or of libdfp.
 ]]
 
 if (DEFINED MONGOCRYPT_DFP_DIR AND NOT MONGOCRYPT_DFP_DIR STREQUAL "USE-SYSTEM")
    message (FATAL_ERROR "The only valid value  for MONGOCRYPT_DFP_DIR is USE-SYSTEM")
 endif ()
 
 function (_import_dfp)
-   find_library (_MONGOCRYPT_SYSTEM_INTEL_DFP_STATIC "${CMAKE_STATIC_LIBRARY_PREFIX}bidgcc000${CMAKE_STATIC_LIBRARY_SUFFIX}")
-   find_path (_MONGOCRYPT_SYSTEM_INTEL_DFP_INCLUDE_DIR bid_conf.h)
-   add_library (intel_dfp STATIC IMPORTED)
-   set_target_properties (intel_dfp PROPERTIES
-      INTERFACE_INCLUDE_DIRECTORIES "${_MONGOCRYPT_SYSTEM_INTEL_DFP_INCLUDE_DIR}"
-      )
-   set_property (TARGET intel_dfp PROPERTY IMPORTED_LOCATION "${_MONGOCRYPT_SYSTEM_INTEL_DFP_STATIC}")
-   set_property (
-      CACHE _MONGOCRYPT_SYSTEM_INTEL_DFP_INCLUDE_DIR
-      PROPERTY ADVANCED
-      TRUE
+   if (NOT _MONGOCRYPT_SYSTEM_DFP_LIB OR NOT _MONGOCRYPT_SYSTEM_DFP_INCLUDE_DIR)
+      message (CHECK_START "Searching for a decimal floating-point library")
+      # Clear prior settings if either one may have been unset:
+      unset (_MONGOCRYPT_SYSTEM_DFP_LIB CACHE)
+      unset (_MONGOCRYPT_SYSTEM_DFP_INCLUDE_DIR CACHE)
+      # Search for the IntelDFP library:
+      find_library (
+         _inteldfp_lib
+         NAMES bidgcc000 "${CMAKE_STATIC_LIBRARY_PREFIX}bidgcc000${CMAKE_STATIC_LIBRARY_SUFFIX}"
+         NO_CACHE
+         )
+      # Search for the libdfp library:
+      find_library (
+         _libdfp_lib
+         NAMES dfp "${CMAKE_STATIC_LIBRARY_PREFIX}dfp${CMAKE_STATIC_LIBRARY_SUFFIX}"
+         NO_CACHE
+         )
+
+      # Search for the include-path for IntelDFP:
+      find_path (_inteldfp_bid_conf_h_dir bid_conf.h NO_CACHE)
+      # Search for math.h contained in libdfp:
+      find_file (_libdfp_dfp_math_h "dfp/math.h" NO_CACHE)
+
+      set (_lib NOTFOUND)
+      set (_inc_dir NOTFOUND)
+      if (_inteldfp_lib AND _inteldfp_bid_conf_h_dir)
+         # Use libdfp:
+         message (CHECK_PASS "Using IntelDFP: ${_inteldfp_lib}")
+         set (_lib "${_inteldfp_lib}")
+         set (_inc_dir "${_inteldfp_bid_conf_h_dir}")
+      elseif (_libdfp_lib AND _libdfp_dfp_math_h)
+         # Use libdfp:
+         message (CHECK_PASS "Using libdfp: ${_libdfp_lib}")
+         set (_lib "${_libdfp_lib}")
+         # We want to add the 'dfp/' directory as an include-dir, so it intercepts
+         # the default stdlib headers:
+         get_filename_component (_inc_dir "${_libdfp_dfp_math_h}" DIRECTORY)
+      else ()
+         # Nope:
+         message (CHECK_FAIL "No decimal floating-point library was found.")
+         message (SEND_ERROR "Failed to import a decimal floating-point library from the system")
+      endif ()
+
+      set (_MONGOCRYPT_SYSTEM_DFP_LIB "${_lib}" CACHE PATH "System DFP library to use")
+      set (_MONGOCRYPT_SYSTEM_DFP_INCLUDE_DIR "${_inc_dir}" CACHE PATH "include-search-dir for the system DFP library")
+      mark_as_advanced (_MONGOCRYPT_SYSTEM_DFP_LIB _MONGOCRYPT_SYSTEM_DFP_INCLUDE_DIR)
+   endif ()
+
+   add_library (_mongocrypt::system-dfp UNKNOWN IMPORTED)
+   set_target_properties (
+      _mongocrypt::system-dfp PROPERTIES
+      IMPORTED_LOCATION "${_MONGOCRYPT_SYSTEM_DFP_LIB}"
+      INTERFACE_INCLUDE_DIRECTORIES "${_MONGOCRYPT_SYSTEM_DFP_INCLUDE_DIR}"
       )
 endfunction ()
 
+# This library is used to pivot the used DFP library at configure/find_package time:
+add_library (_mongocrypt-dfp INTERFACE)
+add_library (mongocrypt::dfp ALIAS _mongocrypt-dfp)
+install (TARGETS _mongocrypt-dfp EXPORT mongocrypt_targets)
+
 if (NOT DEFINED MONGOCRYPT_DFP_DIR)
    # The user did not provide a MONGOCRYPT_DFP_DIR, so we'll set one up
    include (IntelDFP)
 elseif (MONGOCRYPT_DFP_DIR STREQUAL "USE-SYSTEM")
-   message (STATUS "NOTE: Using system-wide Intel DFP library. This is intended only for package maintainers.")
-   set (USE_SYSTEM_INTEL_DFP "ON")
+   message (STATUS "NOTE: Using system-wide DFP library. This is intended only for package maintainers.")
+
    # Do the import in a function to isolate variable scope
    _import_dfp ()
 
-   # Define interface targets to be used to control the DFP used at both build and import time.
-   # Refer to mongocrypt-config.cmake to see how these targets are used by consumers
-   add_library (_mongocrypt-intel_dfp INTERFACE)
-   add_library (mongocrypt::intel_dfp ALIAS _mongocrypt-intel_dfp)
-   install (
-      TARGETS _mongocrypt-intel_dfp
-      EXPORT mongocrypt_targets
-      )
-
-   # Link to Intel DFP, only exporting that usage for the local build tree.
-   # The mongocrypt-config file will later add the appropriate link library for downstream
-   # users during find_package()
-   target_link_libraries (_mongocrypt-intel_dfp INTERFACE $<BUILD_INTERFACE:intel_dfp>)
-
+   # Link to the import target for the system's DFP library.
+   # mongocrypt-config.cmake will later add a matching IMPORTED target
+   # for downstream users during find_package()
+   target_link_libraries (_mongocrypt-dfp INTERFACE _mongocrypt::system-dfp)
+   # Hints for mongocrypt-config.cmake:
+   set (USE_SYSTEM_DFP "ON")
+   get_target_property (_loc _mongocrypt::system-dfp IMPORTED_LOCATION)
+   get_filename_component (SYSTEM_DFP_FILENAME "${_loc}" NAME)
 endif ()
-

cmake/IntelDFP.cmake

@@ -376,30 +376,23 @@ target_compile_definitions (intel_dfp_obj PUBLIC
 target_compile_options (intel_dfp_obj PRIVATE -w)
 target_include_directories(intel_dfp_obj PUBLIC ${intel_dfp_SOURCE_DIR}/LIBRARY/src)
 
-# Define an interface library that attaches the built TUs to the consumer
-add_library (_mongocrypt_intel_dfp INTERFACE)
-add_library (mongocrypt::intel_dfp ALIAS _mongocrypt_intel_dfp)
-
-target_sources (_mongocrypt_intel_dfp
+target_sources (_mongocrypt-dfp
     #[[
-        For targets *within this build* that link with mongocrypt::intel_dfp,
+        For targets *within this build* that link with mongocrypt::dfp,
         inject the generated TUs (object files) from the intel_dfp_obj library.
 
         This will be stripped out of the interface library when it is installed,
-        since we don't want to ship the DFP object separately. Instead, users
+        since we don't want to ship the DFP objects separately. Instead, users
         will link to libmongocrypt, which will contain the necessary TUs for
         the library (because they link to this interface library).
     ]]
     INTERFACE $<BUILD_INTERFACE:$<TARGET_OBJECTS:intel_dfp_obj>>
     )
-target_link_libraries (_mongocrypt_intel_dfp
+target_link_libraries (_mongocrypt-dfp
     INTERFACE
+        # IntelDFP requires that we set certain definitions just to consume its headers:
         $<BUILD_INTERFACE:intel_dfp_obj>
         # We do want to propagate an interface requirement: Some platforms need a
         # separate link library to support special math functions.
         $<$<PLATFORM_ID:Linux>:m>
     )
-
-# Give the installed target a name to indicate its hidden-ness
-set_property (TARGET _mongocrypt_intel_dfp PROPERTY EXPORT_NAME private::intel_dfp_interface)
-install (TARGETS _mongocrypt_intel_dfp EXPORT mongocrypt_targets)

cmake/mongocrypt-config.cmake

@@ -31,12 +31,37 @@ if (_using_shared_libbson AND DEFINED MONGOCRYPT_LIBBSON_SHARED_USE)
     )
 endif ()
 
-set (_using_system_intel_dfp "@USE_SYSTEM_INTEL_DFP@")
+#[[ BOOL:
+    Whether the packaged libmongocrypt expects to use the system's DFP library. Like with
+    libbson noted above, the default configuration embeds the TUs for IntelDFP within libmongocrypt
+    itself. These TUs are defined with special names and won't collide with other DFP libraries
+    that might be used by a final application.
 
-if (_using_system_intel_dfp)
-   find_library (_MONGOCRYPT_SYSTEM_INTEL_DFP_STATIC "${CMAKE_STATIC_LIBRARY_PREFIX}bidgcc000${CMAKE_STATIC_LIBRARY_SUFFIX}")
-   set_property (
-      TARGET mongo::_mongocrypt-intel_dfp
-      PROPERTY IMPORTED_LOCATION "${_MONGOCRYPT_SYSTEM_INTEL_DFP_STATIC}"
-      )
+    If we were built against a system DFP, libmongocrypt will have a transitive usage of
+    _mongocrypt::system-dfp. We will need to define this IMPORTED target.
+]]
+set (_using_system_dfp "@USE_SYSTEM_DFP@")
+#[[ Filename:
+    If this libmongocrypt was built with the system's DFP, this is the filename of the
+    library that was used during the find build. This gives us sufficient information to know
+    resolve the appropriate library for transitive users.
+]]
+set (_system_dfp_filename "@SYSTEM_DFP_FILENAME@")
+
+if (_using_system_dfp)
+    # Find the library on the system that matches the name of the library that we used when
+    # building libmongocrypt. If we found a 'libdfp.so' library, we also want to check for 'libdfp.so.1',
+    # since that is the preferred binary name.
+    find_library (MONGOCRYPT_SYSTEM_DFP_LIB NAMES "${_system_dfp_filename}" "${_system_dfp_filename}.1")
+    if (NOT MONGOCRYPT_SYSTEM_DFP_LIB)
+        message (WARNING
+                 "Unable to find the '${_system_dfp_filename}' decimal floating-point library that is expected by libmongocrypt. "
+                 "Application linking will likely fail. Set MONGOCRYPT_SYSTEM_DFP_LIB to a library path to use.")
+    else ()
+        add_library (_mongocrypt::system-dfp UNKNOWN IMPORTED)
+        set_property (
+            TARGET _mongocrypt::system-dfp
+            PROPERTY IMPORTED_LOCATION "${MONGOCRYPT_SYSTEM_DFP_LIB}"
+            )
+    endif ()
 endif ()

debian/control

@@ -9,7 +9,7 @@ Build-Depends: debhelper (>= 10),
                quilt,
                libssl-dev,
                pkg-config,
-               libintelrdfpmath-dev (>= 2.0u2-6),
+               libdfp-dev (>= 1.0.16-1),
                libbson-dev
 Standards-Version: 4.6.2
 Section: libs
@@ -21,7 +21,6 @@ Architecture: any
 Multi-Arch: same
 Depends: libbson-dev,
          libmongocrypt0 (= ${binary:Version}),
-         libintelrdfpmath-dev (>= 2.0u2-6),
          ${misc:Depends}
 Description: client-side field level encryption library - dev files
  libmongocrypt facilitates the client-side encryption and decryption,

etc/rpm/tweak.awk

@@ -8,6 +8,20 @@
 # Drop the source. We're bringing our own
 /Source0/ { next }
 
+/%package devel/ {
+    # Insert a dep on 'libdfp-devel'
+    print
+    print "BuildRequires: libdfp-devel"
+    print "Requires: libdfp"
+    next
+}
+
+/-DMONGOCRYPT_MONGOC_DIR:STRING=USE-SYSTEM/ {
+    print
+    print "   -DMONGOCRYPT_DFP_DIR=USE-SYSTEM \\"
+    next
+}
+
 # Replace the autosetup with one that copies the source tree into place
 /%autosetup/ {
     print "cp -rf %{_sourcedir}/. %{_builddir}/\n" \