Index: lldb/trunk/test/expression_command/call-function/Makefile
===================================================================
--- lldb/trunk/test/expression_command/call-function/Makefile
+++ lldb/trunk/test/expression_command/call-function/Makefile
@@ -6,7 +6,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/breakpoint/breakpoint_conditions/Makefile
===================================================================
--- lldb/trunk/test/functionalities/breakpoint/breakpoint_conditions/Makefile
+++ lldb/trunk/test/functionalities/breakpoint/breakpoint_conditions/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../../make
 
 C_SOURCES := main.c
-CFLAGS_EXTRAS := -std=c99
+CFLAGS_EXTRAS += -std=c99
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-skip-summary/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-skip-summary/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-skip-summary/Makefile
@@ -6,7 +6,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/iterator/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/iterator/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/iterator/Makefile
@@ -2,14 +2,14 @@
 
 CXX_SOURCES := main.cpp
 
-CFLAGS_EXTRAS := -O0
+CFLAGS_EXTRAS += -O0
 USE_LIBSTDCPP := 1
 
 # clang-3.5+ outputs FullDebugInfo by default for Darwin/FreeBSD 
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/list/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/list/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/list/Makefile
@@ -2,7 +2,7 @@
 
 CXX_SOURCES := main.cpp
 
-CFLAGS_EXTRAS := -O0
+CFLAGS_EXTRAS += -O0
 USE_LIBSTDCPP := 1
 
 # clang-3.5+ outputs FullDebugInfo by default for Darwin/FreeBSD 
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/string/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/string/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/string/Makefile
@@ -2,7 +2,7 @@
 
 CXX_SOURCES := main.cpp
 
-CFLAGS_EXTRAS := -O0
+CFLAGS_EXTRAS += -O0
 USE_LIBSTDCPP := 1
 
 # clang-3.5+ outputs FullDebugInfo by default for Darwin/FreeBSD 
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/vbool/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/vbool/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/vbool/Makefile
@@ -2,7 +2,7 @@
 
 CXX_SOURCES := main.cpp
 
-CFLAGS_EXTRAS := -O0
+CFLAGS_EXTRAS += -O0
 USE_LIBSTDCPP := 1
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/data-formatter-synth/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/data-formatter-synth/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/data-formatter-synth/Makefile
@@ -6,7 +6,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/rdar-9973865/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/rdar-9973865/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/rdar-9973865/Makefile
@@ -5,7 +5,7 @@
 # Workaround for llvm.org/pr16214: clang doesn't emit structure definition DWARF
 # information without the flag below.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/rdar-9974002/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/rdar-9974002/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/rdar-9974002/Makefile
@@ -6,7 +6,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/functionalities/data-formatter/stringprinter/Makefile
===================================================================
--- lldb/trunk/test/functionalities/data-formatter/stringprinter/Makefile
+++ lldb/trunk/test/functionalities/data-formatter/stringprinter/Makefile
@@ -6,7 +6,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/lang/cpp/stl/Makefile
===================================================================
--- lldb/trunk/test/lang/cpp/stl/Makefile
+++ lldb/trunk/test/lang/cpp/stl/Makefile
@@ -9,7 +9,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/make/Makefile.rules
===================================================================
--- lldb/trunk/test/make/Makefile.rules
+++ lldb/trunk/test/make/Makefile.rules
@@ -14,7 +14,7 @@
 #
 # Also might be of interest:
 # FRAMEWORK_INCLUDES (Darwin only) :=
-# CFLAGS_EXTRAS :=
+# CFLAGS_EXTRAS +=
 # LD_EXTRAS :=
 # SPLIT_DEBUG_SYMBOLS := YES
 #
Index: lldb/trunk/test/python_api/lldbutil/iter/Makefile
===================================================================
--- lldb/trunk/test/python_api/lldbutil/iter/Makefile
+++ lldb/trunk/test/python_api/lldbutil/iter/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../../make
 
-CFLAGS_EXTRAS := -D__STDC_LIMIT_MACROS
+CFLAGS_EXTRAS += -D__STDC_LIMIT_MACROS
 ENABLE_THREADS := YES
 CXX_SOURCES := main.cpp
 MAKE_DSYM := NO
Index: lldb/trunk/test/python_api/lldbutil/process/Makefile
===================================================================
--- lldb/trunk/test/python_api/lldbutil/process/Makefile
+++ lldb/trunk/test/python_api/lldbutil/process/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../../make
 
-CFLAGS_EXTRAS := -D__STDC_LIMIT_MACROS
+CFLAGS_EXTRAS += -D__STDC_LIMIT_MACROS
 ENABLE_THREADS := YES
 CXX_SOURCES := main.cpp
 MAKE_DSYM :=NO
Index: lldb/trunk/test/python_api/module_section/Makefile
===================================================================
--- lldb/trunk/test/python_api/module_section/Makefile
+++ lldb/trunk/test/python_api/module_section/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../make
 
-CFLAGS_EXTRAS := -D__STDC_LIMIT_MACROS
+CFLAGS_EXTRAS += -D__STDC_LIMIT_MACROS
 ENABLE_THREADS := YES
 CXX_SOURCES := main.cpp b.cpp c.cpp
 MAKE_DSYM :=NO
Index: lldb/trunk/test/python_api/sbvalue_persist/Makefile
===================================================================
--- lldb/trunk/test/python_api/sbvalue_persist/Makefile
+++ lldb/trunk/test/python_api/sbvalue_persist/Makefile
@@ -9,7 +9,7 @@
 # targets.  Other targets do not, which causes this test to fail.
 # This flag enables FullDebugInfo for all targets.
 ifneq (,$(findstring clang,$(CC)))
-  CFLAGS_EXTRAS := -fno-limit-debug-info
+  CFLAGS_EXTRAS += -fno-limit-debug-info
 endif
 
 include $(LEVEL)/Makefile.rules
Index: lldb/trunk/test/python_api/value_var_update/Makefile
===================================================================
--- lldb/trunk/test/python_api/value_var_update/Makefile
+++ lldb/trunk/test/python_api/value_var_update/Makefile
@@ -1,7 +1,7 @@
 LEVEL = ../../make
 
 C_SOURCES := main.c
-CFLAGS_EXTRAS := -std=c99
+CFLAGS_EXTRAS += -std=c99
 # See TestHelloWorld.py, which specifies the executable name with a dictionary.
 EXE := hello_world
 
Index: lldb/trunk/test/tools/lldb-server/Makefile
===================================================================
--- lldb/trunk/test/tools/lldb-server/Makefile
+++ lldb/trunk/test/tools/lldb-server/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../make
 
-CFLAGS_EXTRAS := -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS
+CFLAGS_EXTRAS += -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS
 ENABLE_THREADS := YES
 CXX_SOURCES := main.cpp
 MAKE_DSYM :=NO
Index: lldb/trunk/test/tools/lldb-server/inferior-crash/Makefile
===================================================================
--- lldb/trunk/test/tools/lldb-server/inferior-crash/Makefile
+++ lldb/trunk/test/tools/lldb-server/inferior-crash/Makefile
@@ -1,6 +1,6 @@
 LEVEL = ../../../make
 
-CFLAGS_EXTRAS := -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS -std=c++11
+CFLAGS_EXTRAS += -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS -std=c++11
 # LD_EXTRAS := -lpthread
 CXX_SOURCES := main.cpp
 MAKE_DSYM :=NO