[lldb] Simplify output for skipped categories in dotest.py

[JDevlieghere]

Summary

Print a single line listing all the categories that are being skipped, rather than relying on the check.*Support() functions specifying why a particular category will be skipped. If we know why a category got skipped, still print that in verbose mode.

The motivation for this change is that sometimes engineers misidentify the output of these messages as the cause for a test failure (e.g. not being able to build libc++ or libstdc++).

[mgorny]

I actually like the verbose output but I guess being more terse by default's fine.

[rupprecht]

The motivation for this change is that sometimes engineers misidentify the output of these messages as the cause for a test failure

I have worked on one these checks and *still* gotten confused by the message, so thanks :)

lldb/packages/Python/lldbsuite/test/dotest.py

def canRunLibcxxTests():
     return False, "Don't know how to build with libc++ on %s" % platform
 
 def checkLibcxxSupport():
     result, reason = canRunLibcxxTests()
     if result:
         return # libc++ supported
     if "libc++" in configuration.categories_list:
         return # libc++ category explicitly requested, let it run.
-    print("Libc++ tests will not be run because: " + reason)
+    if configuration.verbose:
+        print("libc++ tests will not be run because: " + reason)
     configuration.skip_categories.append("libc++")
 
 def canRunLibstdcxxTests():
     from lldbsuite.test import lldbplatformutil
 
     platform = lldbplatformutil.getPlatform()
     if lldbplatformutil.target_is_android():
         platform = "android"
     if platform == "linux":
         return True, "libstdcxx always present"
     return False, "Don't know how to build with libstdcxx on %s" % platform
 
 def checkLibstdcxxSupport():
     result, reason = canRunLibstdcxxTests()
     if result:
         return # libstdcxx supported
     if "libstdcxx" in configuration.categories_list:
         return # libstdcxx category explicitly requested, let it run.
+    if configuration.verbose:
         print("libstdcxx tests will not be run because: " + reason)
     configuration.skip_categories.append("libstdcxx")
 
 def canRunWatchpointTests():
     from lldbsuite.test import lldbplatformutil
 
     platform = lldbplatformutil.getPlatform()
     if platform == "netbsd":
         if os.geteuid() == 0:
def canRunWatchpointTests():
     return True, "watchpoint support available"
 
 def checkWatchpointSupport():
     result, reason = canRunWatchpointTests()
     if result:
         return # watchpoints supported
     if "watchpoint" in configuration.categories_list:
         return # watchpoint category explicitly requested, let it run.
+    if configuration.verbose:
         print("watchpoint tests will not be run because: " + reason)
     configuration.skip_categories.append("watchpoint")
 
 def checkObjcSupport():
     from lldbsuite.test import lldbplatformutil
 
     if not lldbplatformutil.platformIsDarwin():
+        if configuration.verbose:
             print("objc tests will be skipped because of unsupported platform")
         configuration.skip_categories.append("objc")
 
 def checkDebugInfoSupport():
     import lldb
 
     platform = lldb.selected_platform.GetTriple().split('-')[2]
     compiler = configuration.compiler
-    skipped = []
     for cat in test_categories.debug_info_categories:
         if cat in configuration.categories_list:
             continue # Category explicitly requested, let it run.
         if test_categories.is_supported_on_platform(cat, platform, compiler):
             continue
         configuration.skip_categories.append(cat)
-        skipped.append(cat)
-    if skipped:
-        print("Skipping following debug info categories:", skipped)
 
 def checkDebugServerSupport():
     from lldbsuite.test import lldbplatformutil
     import lldb
 
     skip_msg = "Skipping %s tests, as they are not compatible with remote testing on this platform"
     if lldbplatformutil.platformIsDarwin():
         configuration.skip_categories.append("llgs")
         if lldb.remote_platform:
             # <rdar://problem/34539270>
             configuration.skip_categories.append("debugserver")
+            if configuration.verbose:
                 print(skip_msg%"debugserver");
     else:
         configuration.skip_categories.append("debugserver")
         if lldb.remote_platform and lldbplatformutil.getPlatform() == "windows":
             configuration.skip_categories.append("llgs")
+            if configuration.verbose:
                 print(skip_msg%"lldb-server");
 
 def run_suite():
     # On MacOS X, check to make sure that domain for com.apple.DebugSymbols defaults
     # does not exist before proceeding to running the test suite.
     if sys.platform.startswith("darwin"):
         checkDsymForUUIDIsNotOn()
 
     # Start the actions by first parsing the options while setting up the test
def run_suite():
 
     checkLibcxxSupport()
     checkLibstdcxxSupport()
     checkWatchpointSupport()
     checkDebugInfoSupport()
     checkDebugServerSupport()
     checkObjcSupport()
 
+    print("Skipping the following test categories: {}".format(configuration.skip_categories))
+
     for testdir in configuration.testdirs:
         for (dirpath, dirnames, filenames) in os.walk(testdir):
             visit('Test', dirpath, filenames)
 
     #
     # Now that we have loaded all the test cases, run the whole test suite.
     #