Add a test for clang-tidy using the clang cl driver

[zturner]

Summary

In order to get this to work, the positional arguments must use --driver-mode=cl <args>, and NOT clang-cl <args>. In the latter case, clang-tidy has to try really hard to "guess" whether the first argument is argv[0] or argv[1]. This still tests effectively the same thing, but without the convoluted magic of having to care about the name of the tool being run.

This is the test for D23455

[alexfh]

LG with two nits.

In order to get this to work, the positional arguments must use --driver-mode=cl <args>, and NOT clang-cl <args>

It's not that important for the fixed compilation database, as long as there is a way to specify the driver mode. However, we need to make sure clang-tidy is able to figure out correct driver mode from JSON compilation databases generated on Windows for clang-cl builds. It should be a separate test though.

test/clang-tidy/clang-cl-driver.cpp

1 ↗

(On Diff #67948)

I wonder whether the /Dname#value format should work in clang-cl mode as well (it's supported by cl.exe, if I understand https://msdn.microsoft.com/en-us/library/hhzbb5c8.aspx correctly).

18 ↗

(On Diff #67948)

Please fix the "No newline at end of file".

clang-tools-extra/trunk/test/clang-tidy/clang-cl-driver.cpp

+// RUN: clang-tidy -checks=-*,modernize-use-nullptr %s -- --driver-mode=cl /DTEST1 /DFOO=foo /DBAR=bar | FileCheck -implicit-check-not="{{warning|error}}:" %s
+int *a = 0;
+// CHECK: :[[@LINE-1]]:10: warning: use nullptr
+#ifdef TEST1
+int *b = 0;
+// CHECK: :[[@LINE-1]]:10: warning: use nullptr
+#endif
+#define foo 1
+#define bar 1
+#if FOO
+int *c = 0;
+// CHECK: :[[@LINE-1]]:10: warning: use nullptr
+#endif
+#if BAR
+int *d = 0;
+// CHECK: :[[@LINE-1]]:10: warning: use nullptr
+#endif