diff --git a/clang/test/Driver/config-file3.c b/clang/test/Driver/config-file3.c
--- a/clang/test/Driver/config-file3.c
+++ b/clang/test/Driver/config-file3.c
@@ -1,14 +1,15 @@
 // REQUIRES: shell
 // REQUIRES: x86-registered-target
 
+// RUN: rm -rf %t && mkdir %t
+
 //--- If config file is specified by relative path (workdir/cfg-s2), it is searched for by that path.
+
+// RUN: mkdir -p %t/workdir/subdir
+// RUN: echo "@subdir/cfg-s2" > %t/workdir/cfg-1
+// RUN: echo "-Wundefined-var-template" > %t/workdir/subdir/cfg-s2
 //
-// RUN: mkdir -p %T/workdir
-// RUN: echo "@subdir/cfg-s2" > %T/workdir/cfg-1
-// RUN: mkdir -p %T/workdir/subdir
-// RUN: echo "-Wundefined-var-template" > %T/workdir/subdir/cfg-s2
-//
-// RUN: ( cd %T && %clang --config workdir/cfg-1 -c %s -### 2>&1 | FileCheck %s -check-prefix CHECK-REL )
+// RUN: ( cd %t && %clang --config workdir/cfg-1 -c %s -### 2>&1 | FileCheck %s -check-prefix CHECK-REL )
 //
 // CHECK-REL: Configuration file: {{.*}}/workdir/cfg-1
 // CHECK-REL: -Wundefined-var-template
@@ -16,12 +17,11 @@
 
 //--- Invocation qqq-clang-g++ tries to find config file qqq-clang-g++.cfg first.
 //
-// RUN: rm -rf %T/testdmode
-// RUN: mkdir -p %T/testdmode
-// RUN: ln -s %clang %T/testdmode/qqq-clang-g++
-// RUN: echo "-Wundefined-func-template" > %T/testdmode/qqq-clang-g++.cfg
-// RUN: echo "-Werror" > %T/testdmode/qqq.cfg
-// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix FULL-NAME
+// RUN: mkdir %t/testdmode
+// RUN: ln -s %clang %t/testdmode/qqq-clang-g++
+// RUN: echo "-Wundefined-func-template" > %t/testdmode/qqq-clang-g++.cfg
+// RUN: echo "-Werror" > %t/testdmode/qqq.cfg
+// RUN: %t/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix FULL-NAME
 //
 // FULL-NAME: Configuration file: {{.*}}/testdmode/qqq-clang-g++.cfg
 // FULL-NAME: -Wundefined-func-template
@@ -31,20 +31,20 @@
 // (As the clang executable and symlink are in different directories, this
 // requires specifying the path via --config-*-dir= though.)
 //
-// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir=%T/testdmode -c %s -### 2>&1 | FileCheck %s -check-prefix SYMLINK
+// RUN: %t/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir=%t/testdmode -c %s -### 2>&1 | FileCheck %s -check-prefix SYMLINK
 //
 // SYMLINK: Configuration file: {{.*}}/testdmode/qqq-clang-g++.cfg
 //
 //--- File specified by --config overrides config inferred from clang executable.
 //
-// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config i386-qqq -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-EXPLICIT
+// RUN: %t/testdmode/qqq-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config i386-qqq -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-EXPLICIT
 //
 // CHECK-EXPLICIT: Configuration file: {{.*}}/Inputs/config/i386-qqq.cfg
 //
 //--- Invocation qqq-clang-g++ tries to find config file qqq.cfg if qqq-clang-g++.cfg is not found.
 //
-// RUN: rm %T/testdmode/qqq-clang-g++.cfg
-// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix SHORT-NAME
+// RUN: rm %t/testdmode/qqq-clang-g++.cfg
+// RUN: %t/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix SHORT-NAME
 //
 // SHORT-NAME: Configuration file: {{.*}}/testdmode/qqq.cfg
 // SHORT-NAME: -Werror
@@ -53,11 +53,10 @@
 
 //--- Config files are searched for in binary directory as well.
 //
-// RUN: rm -rf %T/testbin
-// RUN: mkdir -p %T/testbin
-// RUN: ln -s %clang %T/testbin/clang
-// RUN: echo "-Werror" > %T/testbin/aaa.cfg
-// RUN: %T/testbin/clang --config-system-dir= --config-user-dir= --config aaa.cfg -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-BIN
+// RUN: mkdir %t/testbin
+// RUN: ln -s %clang %t/testbin/clang
+// RUN: echo "-Werror" > %t/testbin/aaa.cfg
+// RUN: %t/testbin/clang --config-system-dir= --config-user-dir= --config aaa.cfg -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-BIN
 //
 // CHECK-BIN: Configuration file: {{.*}}/testbin/aaa.cfg
 // CHECK-BIN: -Werror
@@ -68,12 +67,11 @@
 
 //--- When reloading config file, x86_64-clang-g++ tries to find config i386-clang-g++.cfg first.
 //
-// RUN: rm -rf %T/testreload
-// RUN: mkdir -p %T/testreload
-// RUN: ln -s %clang %T/testreload/x86_64-clang-g++
-// RUN: echo "-Wundefined-func-template" > %T/testreload/i386-clang-g++.cfg
-// RUN: echo "-Werror" > %T/testreload/i386.cfg
-// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD
+// RUN: mkdir %t/testreload
+// RUN: ln -s %clang %t/testreload/x86_64-clang-g++
+// RUN: echo "-Wundefined-func-template" > %t/testreload/i386-clang-g++.cfg
+// RUN: echo "-Werror" > %t/testreload/i386.cfg
+// RUN: %t/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD
 //
 // CHECK-RELOAD: Configuration file: {{.*}}/testreload/i386-clang-g++.cfg
 // CHECK-RELOAD: -Wundefined-func-template
@@ -81,24 +79,24 @@
 
 //--- If config file is specified by --config and its name does not start with architecture, it is used without reloading.
 //
-// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1a
+// RUN: %t/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1a
 //
 // CHECK-RELOAD1a: Configuration file: {{.*}}/Inputs/config-3.cfg
 //
-// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -target i386 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1b
+// RUN: %t/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -target i386 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1b
 //
 // CHECK-RELOAD1b: Configuration file: {{.*}}/Inputs/config-3.cfg
 
 //--- If config file is specified by --config and its name starts with architecture, it is reloaded.
 //
-// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config x86_64-qqq -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1c
+// RUN: %t/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config x86_64-qqq -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1c
 //
 // CHECK-RELOAD1c: Configuration file: {{.*}}/Inputs/config/i386-qqq.cfg
 
 //--- x86_64-clang-g++ tries to find config i386.cfg if i386-clang-g++.cfg is not found.
 //
-// RUN: rm %T/testreload/i386-clang-g++.cfg
-// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1d
+// RUN: rm %t/testreload/i386-clang-g++.cfg
+// RUN: %t/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1d
 //
 // CHECK-RELOAD1d: Configuration file: {{.*}}/testreload/i386.cfg
 // CHECK-RELOAD1d: -Werror
diff --git a/clang/test/Driver/target-override.c b/clang/test/Driver/target-override.c
--- a/clang/test/Driver/target-override.c
+++ b/clang/test/Driver/target-override.c
@@ -1,16 +1,15 @@
 // REQUIRES: shell
 // REQUIRES: x86-registered-target
 
-// RUN: rm -rf %T/testbin
-// RUN: mkdir -p %T/testbin
-// RUN: ln -s %clang %T/testbin/i386-clang
+// RUN: rm -rf %t && mkdir %t
+// RUN: ln -s %clang %t/i386-clang
 
 // Check if invocation of "foo-clang" adds option "-target foo".
 //
-// RUN: %T/testbin/i386-clang -c -no-canonical-prefixes %s -### 2>&1 | FileCheck -check-prefix CHECK-TG1 %s
+// RUN: %t/i386-clang -c -no-canonical-prefixes %s -### 2>&1 | FileCheck -check-prefix CHECK-TG1 %s
 // CHECK-TG1: Target: i386
 
 // Check if invocation of "foo-clang -target bar" overrides option "-target foo".
 //
-// RUN: %T/testbin/i386-clang -c -no-canonical-prefixes -target x86_64 %s -### 2>&1 | FileCheck -check-prefix CHECK-TG2 %s
+// RUN: %t/i386-clang -c -no-canonical-prefixes -target x86_64 %s -### 2>&1 | FileCheck -check-prefix CHECK-TG2 %s
 // CHECK-TG2: Target: x86_64