1 files changed, 55 insertions, 1 deletions
diff --git a/llvm/tools/llvm-cov/llvm-cov.cpp b/llvm/tools/llvm-cov/llvm-cov.cpp
index 75fa392d6f7..9c9cdef1659 100644
--- a/llvm/tools/llvm-cov/llvm-cov.cpp
+++ b/llvm/tools/llvm-cov/llvm-cov.cpp
@@ -11,9 +11,63 @@
 //
 //===----------------------------------------------------------------------===//
 
-/// \brief The main function for the gcov compatible coverage tool
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Path.h"
+#include <string>
+
+using namespace llvm;
+
+/// \brief The main entry point for the 'show' subcommand.
+int show_main(int argc, const char **argv);
+
+/// \brief The main entry point for the 'report' subcommand.
+int report_main(int argc, const char **argv);
+
+/// \brief The main entry point for the 'convert-for-testing' subcommand.
+int convert_for_testing_main(int argc, const char **argv);
+
+/// \brief The main entry point for the gcov compatible coverage tool.
 int gcov_main(int argc, const char **argv);
 
 int main(int argc, const char **argv) {
+  // If argv[0] is or ends with 'gcov', always be gcov compatible
+  if (sys::path::stem(argv[0]).endswith_lower("gcov"))
+    return gcov_main(argc, argv);
+
+  // Check if we are invoking a specific tool command.
+  if (argc > 1) {
+    int (*func)(int, const char **) = nullptr;
+
+    StringRef command = argv[1];
+    if (command.equals_lower("show"))
+      func = show_main;
+    else if (command.equals_lower("report"))
+      func = report_main;
+    else if (command.equals_lower("convert-for-testing"))
+      func = convert_for_testing_main;
+    else if (command.equals_lower("gcov"))
+      func = gcov_main;
+
+    if (func) {
+      std::string Invocation(std::string(argv[0]) + " " + argv[1]);
+      argv[1] = Invocation.c_str();
+      return func(argc - 1, argv + 1);
+    }
+  }
+
+  // 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 gcov_main(argc, argv);
 }