2015-08-25  Christophe Lyon  <christophe.lyon@linaro.org>

	* lib/target-supports.exp (clear_effective_target_cache): New.
	(check_cached_effective_target): Update et_prop_list.
	* lib/asan-dg.exp (asan_finish): Call clear_effective_target_cache.
	* g++.dg/compat/compat.exp: Likewise.
	* g++.dg/compat/struct-layout-1.exp: Likewise.
	* lib/asan-dg.exp: Likewise.
	* lib/atomic-dg.exp: Likewise.
	* lib/cilk-plus-dg.exp: Likewise.
	* lib/clearcap.exp: Likewise.
	* lib/mpx-dg.exp: Likewise.
	* lib/target-supports.exp: Likewise.
	* lib/tsan-dg.exp: Likewise.
	* lib/ubsan-dg.exp: Likewise.

diff --git a/gcc/testsuite/g++.dg/compat/compat.exp b/gcc/testsuite/g++.dg/compat/compat.exp
index 1272289..4c4b25f 100644
--- a/gcc/testsuite/g++.dg/compat/compat.exp
+++ b/gcc/testsuite/g++.dg/compat/compat.exp
@@ -78,6 +78,7 @@ proc compat-use-tst-compiler { } {
 	set ALWAYS_CXXFLAGS $save_always_cxxflags
 	set ld_library_path $save_ld_library_path
 	set_ld_library_path_env_vars
+	clear_effective_target_cache
     }
 }
 
diff --git a/gcc/testsuite/g++.dg/compat/struct-layout-1.exp b/gcc/testsuite/g++.dg/compat/struct-layout-1.exp
index 7777d98..097a731 100644
--- a/gcc/testsuite/g++.dg/compat/struct-layout-1.exp
+++ b/gcc/testsuite/g++.dg/compat/struct-layout-1.exp
@@ -61,6 +61,7 @@ proc compat-use-alt-compiler { } {
 	set ld_library_path $alt_ld_library_path
 	set_ld_library_path_env_vars
 	restore_gcc_exec_prefix_env_var
+	clear_effective_target_cache
     }
 }
 
diff --git a/gcc/testsuite/lib/asan-dg.exp b/gcc/testsuite/lib/asan-dg.exp
index 141a479..3ce264e 100644
--- a/gcc/testsuite/lib/asan-dg.exp
+++ b/gcc/testsuite/lib/asan-dg.exp
@@ -138,6 +138,7 @@ proc asan_finish { args } {
     }
     set ld_library_path $asan_saved_library_path
     set_ld_library_path_env_vars
+    clear_effective_target_cache
 }
 
 # Symbolize lines like
diff --git a/gcc/testsuite/lib/atomic-dg.exp b/gcc/testsuite/lib/atomic-dg.exp
index d9df227..fe24127 100644
--- a/gcc/testsuite/lib/atomic-dg.exp
+++ b/gcc/testsuite/lib/atomic-dg.exp
@@ -101,4 +101,5 @@ proc atomic_finish { args } {
     } else {
 	unset TEST_ALWAYS_FLAGS
     }
+    clear_effective_target_cache
 }
diff --git a/gcc/testsuite/lib/cilk-plus-dg.exp b/gcc/testsuite/lib/cilk-plus-dg.exp
index 38e5400..7f38f37 100644
--- a/gcc/testsuite/lib/cilk-plus-dg.exp
+++ b/gcc/testsuite/lib/cilk-plus-dg.exp
@@ -101,4 +101,5 @@ proc cilkplus_finish { args } {
     } else {
 	unset TEST_ALWAYS_FLAGS
     }
+    clear_effective_target_cache
 }
diff --git a/gcc/testsuite/lib/clearcap.exp b/gcc/testsuite/lib/clearcap.exp
index d41aa1e..3e2a88c 100644
--- a/gcc/testsuite/lib/clearcap.exp
+++ b/gcc/testsuite/lib/clearcap.exp
@@ -55,4 +55,5 @@ proc clearcap-finish { args } {
     } else {
 	unset TEST_ALWAYS_FLAGS
     }
+    clear_effective_target_cache
 }
diff --git a/gcc/testsuite/lib/mpx-dg.exp b/gcc/testsuite/lib/mpx-dg.exp
index c8f64cd..b2bd40c 100644
--- a/gcc/testsuite/lib/mpx-dg.exp
+++ b/gcc/testsuite/lib/mpx-dg.exp
@@ -142,4 +142,5 @@ proc mpx_finish { args } {
     }
     set ld_library_path $mpx_saved_library_path
     set_ld_library_path_env_vars
+    clear_effective_target_cache
 }
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 1988301..e2084bb 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -117,6 +117,7 @@ proc current_target_name { } {
 
 proc check_cached_effective_target { prop args } {
     global et_cache
+    global et_prop_list
 
     set target [current_target_name]
     if {![info exists et_cache($prop,target)]
@@ -124,12 +125,30 @@ proc check_cached_effective_target { prop args } {
 	verbose "check_cached_effective_target $prop: checking $target" 2
 	set et_cache($prop,target) $target
 	set et_cache($prop,value) [uplevel eval $args]
+	lappend et_prop_list $prop
+	verbose "check_cached_effective_target cached list is now: $et_prop_list" 2
     }
     set value $et_cache($prop,value)
     verbose "check_cached_effective_target $prop: returning $value for $target" 2
     return $value
 }
 
+# Clear effective-target cache. This is useful after testing
+# effective-target features and overriding TEST_ALWAYS_FLAGS and/or
+# ALWAYS_CXXFLAGS.
+
+proc clear_effective_target_cache { } {
+    global et_cache
+    global et_prop_list
+
+    verbose "clear_effective_target_cache: $et_prop_list" 2
+    foreach prop $et_prop_list {
+	unset et_cache($prop,value)
+	unset et_cache($prop,target)
+    }
+    unset et_prop_list
+}
+
 # Like check_compile, but delete the output file and return true if the
 # compiler printed no messages.
 proc check_no_compiler_messages_nocache {args} {
diff --git a/gcc/testsuite/lib/tsan-dg.exp b/gcc/testsuite/lib/tsan-dg.exp
index eb528f8..ff51fdf 100644
--- a/gcc/testsuite/lib/tsan-dg.exp
+++ b/gcc/testsuite/lib/tsan-dg.exp
@@ -149,4 +149,5 @@ proc tsan_finish { args } {
     }
     set ld_library_path $tsan_saved_library_path
     set_ld_library_path_env_vars
+    clear_effective_target_cache
 }
diff --git a/gcc/testsuite/lib/ubsan-dg.exp b/gcc/testsuite/lib/ubsan-dg.exp
index 81934bb..65799db 100644
--- a/gcc/testsuite/lib/ubsan-dg.exp
+++ b/gcc/testsuite/lib/ubsan-dg.exp
@@ -121,4 +121,5 @@ proc ubsan_finish { args } {
     }
     set ld_library_path $ubsan_saved_library_path
     set_ld_library_path_env_vars
+    clear_effective_target_cache
 }