deps: vendor Abseil and update re2 to 2025-11-05

.gitmodules

@@ -127,3 +127,6 @@
 [submodule "3rdparty/rapidhash"]
 	path = 3rdparty/rapidhash
 	url = https://github.com/Nicoshev/rapidhash
+[submodule "3rdparty/abseil-cpp"]
+	path = 3rdparty/abseil-cpp
+	url = https://github.com/abseil/abseil-cpp

cmake/OssiaDeps.cmake

@@ -3,6 +3,7 @@ find_package(Git)
 if(Git_FOUND AND OSSIA_SUBMODULE_AUTOUPDATE)
   message(STATUS "Update general libossia dependencies :")
   set(OSSIA_SUBMODULES
+      abseil-cpp
       concurrentqueue
       compile-time-regular-expressions
       Flicks
@@ -85,6 +86,7 @@ if(Git_FOUND AND OSSIA_SUBMODULE_AUTOUPDATE)
 endif()
 
 # Download various dependencies
+include(deps/abseil)
 include(deps/boost)
 include(deps/concurrentqueue)
 include(deps/ctre)

cmake/deps/abseil.cmake

@@ -0,0 +1,49 @@
+if(OSSIA_USE_SYSTEM_LIBRARIES)
+  find_package(absl CONFIG GLOBAL QUIET)
+endif()
+
+# Abseil is pulled in as a dependency of re2 (see deps/re2.cmake).
+# We build the in-tree copy through its own CMake build, like the other
+# add_subdirectory-based dependencies (rubberband, libremidi, ...).
+if(NOT TARGET absl::strings)
+  block()
+    set(BUILD_SHARED_LIBS 0)
+    set(BUILD_TESTING 0)
+    set(ABSL_BUILD_TESTING OFF CACHE INTERNAL "")
+    set(ABSL_PROPAGATE_CXX_STD ON CACHE INTERNAL "")
+    # Treat Abseil's headers as system headers so that re2 (and ossia) do not
+    # get flooded with warnings coming from them.
+    set(ABSL_USE_SYSTEM_INCLUDES ON CACHE INTERNAL "")
+
+    # Abseil's CMakeLists forcibly overrides CMAKE_MSVC_RUNTIME_LIBRARY from its
+    # own ABSL_MSVC_STATIC_RUNTIME option (default OFF -> /MD), ignoring what the
+    # rest of the build selected. Static ossia builds (Max/PD/Python/Unity, ...)
+    # use the static /MT runtime, which then mismatches Abseil's /MD at link
+    # time. Mirror ossia's choice so the runtimes agree.
+    if(MSVC AND CMAKE_MSVC_RUNTIME_LIBRARY AND NOT CMAKE_MSVC_RUNTIME_LIBRARY MATCHES "DLL")
+      set(ABSL_MSVC_STATIC_RUNTIME ON CACHE INTERNAL "")
+    else()
+      set(ABSL_MSVC_STATIC_RUNTIME OFF CACHE INTERNAL "")
+    endif()
+
+    # When we install our static dependencies, re2 links Abseil publicly, so its
+    # targets must be installable/exportable too.
+    if(OSSIA_INSTALL_STATIC_DEPENDENCIES)
+      set(ABSL_ENABLE_INSTALL ON CACHE INTERNAL "")
+
+      # NB: no EXCLUDE_FROM_ALL here. CMake skips the install() rules of a
+      # subdirectory added with EXCLUDE_FROM_ALL, so Abseil's libraries,
+      # headers and CMake package (abslConfig / abslTargets) would never be
+      # installed - leaving the installed re2 export (which links Abseil
+      # publicly) dangling for downstream consumers. Building all of Abseil is
+      # acceptable here as this branch is only taken for static packaging builds.
+      add_subdirectory("${OSSIA_3RDPARTY_FOLDER}/abseil-cpp")
+    else()
+      add_subdirectory("${OSSIA_3RDPARTY_FOLDER}/abseil-cpp" EXCLUDE_FROM_ALL)
+    endif()
+  endblock()
+endif()
+
+if(TARGET absl::strings)
+  set(OSSIA_HAS_ABSEIL 1 CACHE INTERNAL "")
+endif()

cmake/deps/re2.cmake

@@ -32,7 +32,6 @@ else()
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/regexp.cc
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/set.cc
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/simplify.cc
-    ${OSSIA_3RDPARTY_FOLDER}/re2/re2/stringpiece.cc
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/tostring.cc
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/unicode_casefold.cc
     ${OSSIA_3RDPARTY_FOLDER}/re2/re2/unicode_groups.cc
@@ -55,6 +54,27 @@ else()
 
   target_include_directories(re2 SYSTEM PUBLIC $<BUILD_INTERFACE:${OSSIA_3RDPARTY_FOLDER}/re2>)
 
+  # Since 2023-07-01, re2 depends on Abseil (see deps/abseil.cmake which is
+  # included before this file). This is the set of targets listed in re2's own
+  # CMakeLists.txt (ABSL_DEPS).
+  target_link_libraries(re2 PUBLIC
+    absl::absl_check
+    absl::absl_log
+    absl::base
+    absl::core_headers
+    absl::fixed_array
+    absl::flags
+    absl::flat_hash_map
+    absl::flat_hash_set
+    absl::hash
+    absl::inlined_vector
+    absl::optional
+    absl::span
+    absl::str_format
+    absl::strings
+    absl::synchronization
+  )
+
   if(UNIX)
     target_link_libraries(re2 PUBLIC Threads::Threads)
   endif()
@@ -68,7 +88,10 @@ else()
 
     install(EXPORT re2-exports
             DESTINATION lib/cmake/re2)
-    export(EXPORT re2-exports)
+    # NB: no build-tree export() here. re2 links Abseil publicly and Abseil only
+    # provides install(EXPORT) rules, not a build-tree export(), so a build-tree
+    # export() of re2 fails at generate time ("target ... not in any export
+    # set"). Only the installed re2 export is consumed (see ossiaConfig.cmake.in).
   endif()
 endif()
 

cmake/deps/span.cmake

@@ -2,8 +2,12 @@ if(OSSIA_USE_SYSTEM_LIBRARIES)
   find_package(span CONFIG GLOBAL)
 endif()
 
+# NB: the backing target is named "ossia_span" rather than "span" to avoid a
+# clash with Abseil, which registers an un-prefixed "span" target (alias
+# absl::span) when ABSL_ENABLE_INSTALL is ON (see deps/abseil.cmake). Consumers
+# use the span::span alias.
 if(NOT TARGET span::span)
-  add_library(span INTERFACE IMPORTED GLOBAL)
-  add_library(span::span ALIAS span)
-  target_include_directories(span INTERFACE "$<BUILD_INTERFACE:${OSSIA_3RDPARTY_FOLDER}/span/include>")
+  add_library(ossia_span INTERFACE IMPORTED GLOBAL)
+  add_library(span::span ALIAS ossia_span)
+  target_include_directories(ossia_span INTERFACE "$<BUILD_INTERFACE:${OSSIA_3RDPARTY_FOLDER}/span/include>")
 endif()

cmake/ossiaConfig.cmake.in

@@ -7,6 +7,9 @@ find_dependency(Boost 1.83 REQUIRED)
 
 if(@OSSIA_STATIC@)
   if(EXISTS "${OSSIA_CMAKE_DIR}/../re2/re2-exports.cmake")
+    # re2 links Abseil publicly, so its targets must be resolved before the re2
+    # export (which references absl::*) is pulled in.
+    find_dependency(absl)
     include("${OSSIA_CMAKE_DIR}/../re2/re2-exports.cmake")
   endif()
 endif()