Commit 3f62de0edd for aom

commit 3f62de0eddedb9a246d32b150d6bc47baa790282
Author: James Zern <jzern@google.com>
Date:   Tue Jun 16 13:27:09 2026 -0700

    cmake: fix compiler flag propagation after 3.30.0

    Since https://gitlab.kitware.com/cmake/cmake/-/commit/cebcc07a80,
    `check_symbol_exists()` will modify `CMAKE_<LANG>_FLAGS{,_<CONFIG>}` and
    then restore the values afterward. This will create a normal variable
    which will override the cached variable libaom uses in checking for
    flags (in e.g., `require_c_flag()`). Due to the level of scope involved,
    it's easier to clear the normal variable rather than try to propagate
    the value up through the intermediate scopes.

    Bug: 474642915, 524319756
    Fixed: 524319756
    Change-Id: Iaffaa9fe73d6647e84ea700ed696d40fd6e05ee3

diff --git a/cmake/aom_configure.cmake b/cmake/aom_configure.cmake
index 0401386396..52aa37e24b 100644
--- a/cmake/aom_configure.cmake
+++ b/cmake/aom_configure.cmake
@@ -265,6 +265,26 @@ if(HAVE_PTHREAD_H)
   check_symbol_exists(pthread_setname_np pthread.h _HAS_PTHREAD_SETNAME_NP)
   aom_pop_var(CMAKE_REQUIRED_DEFINITIONS)

+  # Since https://gitlab.kitware.com/cmake/cmake/-/commit/cebcc07a80 (included
+  # in 3.30.0), check_symbol_exists() will modify CMAKE_<LANG>_FLAGS{,_<CONFIG>}
+  # and then restore the values afterward. This will create a normal variable
+  # which will override the cached variable libaom uses in checking for flags.
+  # Due to the level of scope involved, it's easier to clear the normal variable
+  # rather than try to propagate the value up through the intermediate scopes.
+  if(CMAKE_TRY_COMPILE_CONFIGURATION)
+    string(TOUPPER "${CMAKE_TRY_COMPILE_CONFIGURATION}" tc_config)
+  else()
+    set(tc_config "DEBUG")
+  endif()
+  set(tc_config "CMAKE_C_FLAGS_${tc_config}")
+  foreach(config ${AOM_C_CONFIGS})
+    if(${config} STREQUAL ${tc_config})
+      unset(${config})
+      break()
+    endif()
+  endforeach()
+  unset(tc_config)
+
   set(HAVE_PTHREAD_SETNAME_NP ${_HAS_PTHREAD_SETNAME_NP})
 endif()