dependency: bump abseil-cpp to 20260107.1

cmake/dependencies/CMakeLists.txt

@@ -20,6 +20,7 @@ if(BUILD_ZLIB)
     UPDATE_COMMAND git reset --hard
     PATCH_COMMAND git apply --ignore-whitespace
     "${CMAKE_CURRENT_LIST_DIR}/../../patches/ZLIB-v1.3.1.patch"
+    SYSTEM
   )
   set(ZLIB_BUILD_EXAMPLES OFF)
   FetchContent_MakeAvailable(ZLIB)
@@ -36,17 +37,18 @@ if(BUILD_absl)
   FetchContent_Declare(
     absl
     GIT_REPOSITORY "https://github.com/abseil/abseil-cpp.git"
-    GIT_TAG "20250814.1"
+    GIT_TAG "20260107.1"
     GIT_SHALLOW TRUE
     UPDATE_COMMAND git reset --hard
     PATCH_COMMAND git apply --ignore-whitespace
-    "${CMAKE_CURRENT_LIST_DIR}/../../patches/abseil-cpp-20250814.1.patch"
+    "${CMAKE_CURRENT_LIST_DIR}/../../patches/abseil-cpp-20260107.1.patch"
     OVERRIDE_FIND_PACKAGE
+    SYSTEM
   )
   set(ABSL_USE_SYSTEM_INCLUDES ON)
   # We want Abseil to declare what C++ standard it was compiled with.
   set(ABSL_PROPAGATE_CXX_STD ON)
-  set(ABSL_BUILD_TEST_HELPERS ON)
+  set(ABSL_BUILD_TEST_HELPERS OFF)
   set(ABSL_USE_EXTERNAL_GOOGLETEST ON)
   set(ABSL_FIND_GOOGLETEST OFF)
   # We want Abseil to keep the INSTALL rules enabled, even though it is a
@@ -74,6 +76,7 @@ if(BUILD_Protobuf)
     PATCH_COMMAND git apply --ignore-whitespace
     "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v33.1.patch"
     OVERRIDE_FIND_PACKAGE # Make package visible for "protobuf-matchers" below
+    SYSTEM
   )
   set(protobuf_BUILD_TESTS OFF)
   set(protobuf_BUILD_SHARED_LIBS ON)
@@ -99,6 +102,7 @@ if(BUILD_re2)
     UPDATE_COMMAND git reset --hard
     PATCH_COMMAND git apply --ignore-whitespace
     "${CMAKE_CURRENT_LIST_DIR}/../../patches/re2-2025-08-12.patch"
+    SYSTEM
   )
   set(RE2_BUILD_TESTING OFF)
   FetchContent_MakeAvailable(re2)
@@ -121,6 +125,7 @@ if(BUILD_googletest)
     UPDATE_COMMAND git reset --hard
     PATCH_COMMAND git apply --ignore-whitespace
     "${CMAKE_CURRENT_LIST_DIR}/../../patches/googletest-v1.17.0.patch"
+    SYSTEM
   )
   set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
   set(GTEST_HAS_ABSL ON)
@@ -139,6 +144,7 @@ if(BUILD_benchmark)
     GIT_TAG v1.9.2
     GIT_SHALLOW TRUE
     #PATCH_COMMAND git apply --ignore-whitespace ""
+    SYSTEM
   )
   set(BENCHMARK_ENABLE_TESTING OFF)
   set(BENCHMARK_ENABLE_WERROR OFF)

patches/abseil-cpp-20260107.1.patch

@@ -0,0 +1,38 @@
+diff --git a/CMake/AbseilHelpers.cmake b/CMake/AbseilHelpers.cmake
+index 61e1ae4..3e6ec94 100644
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -350,7 +350,7 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
+     endif()
+   endif()
+
+-  if(ABSL_ENABLE_INSTALL)
++  if(ABSL_ENABLE_INSTALL AND NOT ABSL_CC_LIB_TESTONLY)
+     install(TARGETS ${_NAME} EXPORT ${PROJECT_NAME}Targets
+           RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+           LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 26dc8e7..cd4fef1 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -145,7 +145,7 @@ if((BUILD_TESTING AND ABSL_BUILD_TESTING) OR ABSL_BUILD_TEST_HELPERS)
+         add_library(GTest::gmock ALIAS gmock)
+         add_library(GTest::gmock_main ALIAS gmock_main)
+       else()
+-        message(FATAL_ERROR "ABSL_USE_EXTERNAL_GOOGLETEST is ON and ABSL_FIND_GOOGLETEST is OFF, which means that the top-level project must build the Google Test project. However, the target gtest was not found.")
++        message(WARNING "ABSL_USE_EXTERNAL_GOOGLETEST is ON and ABSL_FIND_GOOGLETEST is OFF, which means that the top-level project must build the Google Test project. However, the target gtest was not found.")
+       endif()
+     endif()
+   else()
+diff --git a/absl/container/CMakeLists.txt b/absl/container/CMakeLists.txt
+index 365c6ea..d12e585 100644
+--- a/absl/container/CMakeLists.txt
++++ b/absl/container/CMakeLists.txt
+@@ -1119,6 +1119,7 @@ absl_cc_library(
+     absl::config
+     absl::test_instance_tracker
+     GTest::gmock
++  TESTONLY
+ )
+
+ absl_cc_library(