llvm-cov: Require a subcommand when invoked as llvm-cov

A while ago llvm-cov gained support for clang's instrumentation based
profiling in addition to its gcov support, and subcommands were added
to choose which behaviour to use. When no subcommand was specified, we
fell back to gcov compatibility with a warning that a subcommand would
be required in the future. Now, we require the subcommand.

Note that if the basename of llvm-cov is gcov (via symlink or
hardlink, for example), we still use the gcov compatible behaviour
with no subcommand required.

llvm-svn: 233132

1 files changed, 16 insertions, 16 deletions

diff --git a/llvm/tools/llvm-cov/llvm-cov.cpp b/llvm/tools/llvm-cov/llvm-cov.cpp
index 3b7cffc..bf66f58 100644
--- a/llvm/tools/llvm-cov/llvm-cov.cpp
+++ b/llvm/tools/llvm-cov/llvm-cov.cpp
@@ -14,6 +14,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
 #include "llvm/Support/raw_ostream.h"
 #include <string>
 
@@ -33,8 +34,12 @@ int gcovMain(int argc, const char *argv[]);
 
 /// \brief Top level help.
 static int helpMain(int argc, const char *argv[]) {
-  errs() << "OVERVIEW: LLVM code coverage tool\n\n"
-         << "USAGE: llvm-cov {gcov|report|show}\n";
+  errs() << "Usage: llvm-cov {gcov|report|show} [OPTION]...\n\n"
+         << "Shows code coverage information.\n\n"
+         << "Subcommands:\n"
+         << "  gcov:   Work with the gcov format.\n"
+         << "  show:   Annotate source files using instrprof style coverage.\n"
+         << "  report: Summarize instrprof style coverage information.\n";
   return 0;
 }
 
@@ -61,18 +66,13 @@ int main(int argc, const char **argv) {
     }
   }
 
-  // Give a warning and fall back to gcov
-  errs().changeColor(raw_ostream::RED);
-  errs() << "warning:";
-  // Assume that argv[1] wasn't a command when it stats with a '-' or is a
-  // filename (i.e. contains a '.')
-  if (argc > 1 && !StringRef(argv[1]).startswith("-") &&
-      StringRef(argv[1]).find(".") == StringRef::npos)
-    errs() << " Unrecognized command '" << argv[1] << "'.";
-  errs() << " Using the gcov compatible mode "
-            "(this behaviour may be dropped in the future).";
-  errs().resetColor();
-  errs() << "\n";
-
-  return gcovMain(argc, argv);
+  if (argc > 1) {
+    if (sys::Process::StandardErrHasColors())
+      errs().changeColor(raw_ostream::RED);
+    errs() << "Unrecognized command: " << argv[1] << ".\n\n";
+    if (sys::Process::StandardErrHasColors())
+      errs().resetColor();
+  }
+  helpMain(argc, argv);
+  return 1;
 }