diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -8304,12 +8304,14 @@
     // Check if global/static variable is defined in address space
     // 1~6 (__flash, __flash1, __flash2, __flash3, __flash4, __flash5)
     // but not constant.
-    LangAS AS = D->getType().getAddressSpace();
-    if (isTargetAddressSpace(AS) && 1 <= toTargetAddressSpace(AS) &&
-        toTargetAddressSpace(AS) <= 6 && !D->getType().isConstQualified())
-      CGM.getDiags().Report(D->getLocation(),
-                            diag::err_verify_nonconst_addrspace)
-          << "__flash*";
+    if (D) {
+      LangAS AS = D->getType().getAddressSpace();
+      if (isTargetAddressSpace(AS) && 1 <= toTargetAddressSpace(AS) &&
+          toTargetAddressSpace(AS) <= 6 && !D->getType().isConstQualified())
+        CGM.getDiags().Report(D->getLocation(),
+                              diag::err_verify_nonconst_addrspace)
+            << "__flash*";
+    }
     return TargetCodeGenInfo::getGlobalVarAddressSpace(CGM, D);
   }
 
diff --git a/clang/lib/Driver/ToolChains/AVR.cpp b/clang/lib/Driver/ToolChains/AVR.cpp
--- a/clang/lib/Driver/ToolChains/AVR.cpp
+++ b/clang/lib/Driver/ToolChains/AVR.cpp
@@ -379,6 +379,11 @@
   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
                           options::OPT_fno_use_init_array, false))
     CC1Args.push_back("-fno-use-init-array");
+  // Use `-fno-use-cxa-atexit` as default, since avr-libc does not support
+  // `__cxa_atexit()`.
+  if (!DriverArgs.hasFlag(options::OPT_fuse_cxa_atexit,
+                          options::OPT_fno_use_cxa_atexit, false))
+    CC1Args.push_back("-fno-use-cxa-atexit");
 }
 
 Tool *AVRToolChain::buildLinker() const {
diff --git a/clang/test/Driver/avr-toolchain.c b/clang/test/Driver/avr-toolchain.c
--- a/clang/test/Driver/avr-toolchain.c
+++ b/clang/test/Driver/avr-toolchain.c
@@ -25,7 +25,12 @@
 // CHECK3-SAME: {{^}} "[[SYSROOT]]/usr/avr/include"
 
 // RUN: %clang %s -### -target avr 2>&1 | FileCheck -check-prefix=CC1 %s
-// CC1: clang{{.*}} "-cc1" "-triple" "avr" {{.*}} "-fno-use-init-array"
+// CC1: clang{{.*}} "-cc1" "-triple" "avr" {{.*}} "-fno-use-init-array" "-fno-use-cxa-atexit"
+
+// RUN: %clang %s -### -target avr -fuse-init-array -fuse-cxa-atexit 2>&1 | FileCheck -check-prefix=CHECK4 %s
+// CHECK4: clang{{.*}} "-cc1" "-triple" "avr"
+// CHECK4-NOT: "-fno-use-init-array"
+// CHECK4-NOT: "-fno-use-cxa-atexit"
 
 // RUN: %clang %s -### -target avr --sysroot %S/Inputs/basic_avr_tree 2>&1 -nostdinc | FileCheck --check-prefix=NOSTDINC %s
 // RUN: %clang %s -### -target avr --sysroot %S/Inputs/basic_avr_tree 2>&1 -nostdlibinc | FileCheck --check-prefix=NOSTDINC %s