From 87cf39dce9df59cbd23e6f62be1a83455a2bab6a Mon Sep 17 00:00:00 2001
From: tianrking <10758833+tianrking@users.noreply.github.com>
Date: Thu, 16 Jul 2026 12:20:30 +0800
Subject: [PATCH] cmake: skip probes for required C++ standard

---
 CMake/AbseilDll.cmake | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake
index 18f4f33da70..8abab5d21f6 100644
--- a/CMake/AbseilDll.cmake
+++ b/CMake/AbseilDll.cmake
@@ -724,10 +724,18 @@ set(ABSL_INTERNAL_TEST_DLL_TARGETS
   "status_matchers"
 )
 
-include(CheckCXXSourceCompiles)
+if(DEFINED CMAKE_CXX_STANDARD AND CMAKE_CXX_STANDARD_REQUIRED)
+  if(CMAKE_CXX_STANDARD GREATER_EQUAL 20)
+    set(ABSL_INTERNAL_AT_LEAST_CXX20 ON)
+    set(ABSL_INTERNAL_AT_LEAST_CXX17 ON)
+  elseif(CMAKE_CXX_STANDARD GREATER_EQUAL 17)
+    set(ABSL_INTERNAL_AT_LEAST_CXX17 ON)
+  endif()
+else()
+  include(CheckCXXSourceCompiles)
 
-check_cxx_source_compiles(
-  [==[
+  check_cxx_source_compiles(
+    [==[
 #ifdef _MSC_VER
 #  if _MSVC_LANG < 201703L
 #    error "The compiler defaults or is configured for C++ < 17"
@@ -737,10 +745,10 @@ check_cxx_source_compiles(
 #endif
 int main() { return 0; }
 ]==]
-  ABSL_INTERNAL_AT_LEAST_CXX17)
+    ABSL_INTERNAL_AT_LEAST_CXX17)
 
-check_cxx_source_compiles(
-  [==[
+  check_cxx_source_compiles(
+    [==[
 #ifdef _MSC_VER
 #  if _MSVC_LANG < 202002L
 #    error "The compiler defaults or is configured for C++ < 20"
@@ -750,7 +758,8 @@ check_cxx_source_compiles(
 #endif
 int main() { return 0; }
 ]==]
-  ABSL_INTERNAL_AT_LEAST_CXX20)
+    ABSL_INTERNAL_AT_LEAST_CXX20)
+endif()
 
 if(ABSL_INTERNAL_AT_LEAST_CXX20)
   set(ABSL_INTERNAL_CXX_STD_FEATURE cxx_std_20)