[clang] [test] Pass -ccc-install-dir in mac compilation db test

[mgorny]

Summary

Pass -ccc-install-dir explicitly as the compilation database code does
not pass argv[0] to getMainExecutable(), while some systems require it
to return the correct path. Since the relevant code is apparently only
applicable to Darwin, just pass correct -ccc-install-dir to make
the tests pass on *BSD systems.

[ilya-biryukov]

LGTM to unbreak the tests on *BSD, but could you please leave a comment?
It would probably be best to take argv[0] into account on *BSD systems as well (possibly only if clang could not be found).

At least if that's the behaviour on all other systems.

test/Tooling/clang-check-mac-libcxx-fixed-compilation-db.cpp

15 ↗

(On Diff #182701)

Could you leave a comment this is passed to unbreak *BSD tests?

[mgorny]

In D56976#1365001, @ilya-biryukov wrote:

LGTM to unbreak the tests on *BSD, but could you please leave a comment?
It would probably be best to take argv[0] into account on *BSD systems as well (possibly only if clang could not be found).

At least if that's the behaviour on all other systems.

Actually, it works on other systems because they don't use argv[0]. The problem is in compilation db code using getMainExecutable() in ctor without passing the real argv to it.

[ilya-biryukov]

In D56976#1365087, @mgorny wrote:

Actually, it works on other systems because they don't use argv[0]. The problem is in compilation db code using getMainExecutable() in ctor without passing the real argv to it.

But it does so in all OSes and still manages find libc++, right? What's different for *BSD?

One possible fix is to start passing proper argv[0] into getMainExecutable, but my expectation is that using clang there was intentional: the tooling library tries to fallback to the system clang in that case.

[ilya-biryukov]

Was confused about your comment, so it works on other systems because they don't rely on argv[0] to get the path to main executable. Got you.

[mgorny]

Added a comment as requested.

[mgorny]

In D56976#1365190, @ilya-biryukov wrote:

Was confused about your comment, so it works on other systems because they don't rely on argv[0] to get the path to main executable. Got you.

Exactly.

[ilya-biryukov]

LGTM

cfe/trunk/test/Tooling/clang-check-mac-libcxx-fixed-compilation-db.cpp

 // Clang on MacOS can find libc++ living beside the installed compiler.
 // This test makes sure our libTooling-based tools emulate this properly with
 // fixed compilation database.
 //
 // RUN: rm -rf %t
 // RUN: mkdir %t
 //
 // Install the mock libc++ (simulates the libc++ directory structure).
 // RUN: cp -r %S/Inputs/mock-libcxx %t/
 //
 // RUN: cp clang-check %t/mock-libcxx/bin/
 // RUN: cp %s %t/test.cpp
-// RUN: "%t/mock-libcxx/bin/clang-check" -p %t %t/test.cpp -- -stdlib=libc++ -target x86_64-apple-darwin
+// RUN: "%t/mock-libcxx/bin/clang-check" -p %t %t/test.cpp -- \
+// RUN:     -stdlib=libc++ -target x86_64-apple-darwin \
+// RUN:     -ccc-install-dir %t/mock-libcxx/bin
+//
+// ^ -ccc-install-dir passed to unbreak tests on *BSD where
+//   getMainExecutable() relies on real argv[0] being passed
 #include <mock_vector>
 vector v;