llvmc: Add a '-time' option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86348 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CompilerDriver/Action.cpp b/lib/CompilerDriver/Action.cpp
index 5fd63ee..7bcd30a 100644
--- a/lib/CompilerDriver/Action.cpp
+++ b/lib/CompilerDriver/Action.cpp
@@ -13,9 +13,13 @@
 
 #include "llvm/CompilerDriver/Action.h"
 #include "llvm/CompilerDriver/BuiltinOptions.h"
+
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/System/Program.h"
+#include "llvm/System/TimeValue.h"
+
 #include <stdexcept>
+#include <string>
 
 using namespace llvm;
 using namespace llvmc;
@@ -60,14 +64,31 @@
   }
 }
 
+namespace llvmc {
+  void AppendToGlobalTimeLog(const std::string& cmd, double time);
+}
+
 int llvmc::Action::Execute() const {
   if (DryRun || VerboseMode) {
     errs() << Command_ << " ";
     std::for_each(Args_.begin(), Args_.end(), print_string);
     errs() << '\n';
   }
-  if (DryRun)
-    return 0;
-  else
-    return ExecuteProgram(Command_, Args_);
+  if (!DryRun) {
+    if (Time) {
+      sys::TimeValue now = sys::TimeValue::now();
+      int ret = ExecuteProgram(Command_, Args_);
+      sys::TimeValue now2 = sys::TimeValue::now();
+      now2 -= now;
+      double elapsed = now2.seconds()  + now2.microseconds()  / 1000000.0;
+      AppendToGlobalTimeLog(Command_, elapsed);
+
+      return ret;
+    }
+    else {
+      return ExecuteProgram(Command_, Args_);
+    }
+  }
+
+  return 0;
 }
diff --git a/lib/CompilerDriver/BuiltinOptions.cpp b/lib/CompilerDriver/BuiltinOptions.cpp
index d90c50d..d1ac8c9 100644
--- a/lib/CompilerDriver/BuiltinOptions.cpp
+++ b/lib/CompilerDriver/BuiltinOptions.cpp
@@ -30,8 +30,10 @@
 cl::list<std::string> Languages("x",
           cl::desc("Specify the language of the following input files"),
           cl::ZeroOrMore);
+
 cl::opt<bool> DryRun("dry-run",
                      cl::desc("Only pretend to run commands"));
+cl::opt<bool> Time("time", cl::desc("Time individual commands"));
 cl::opt<bool> VerboseMode("v",
                           cl::desc("Enable verbose mode"));
 
diff --git a/lib/CompilerDriver/Main.cpp b/lib/CompilerDriver/Main.cpp
index c581809..3a3487a 100644
--- a/lib/CompilerDriver/Main.cpp
+++ b/lib/CompilerDriver/Main.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/System/Path.h"
 
+#include <sstream>
 #include <stdexcept>
 #include <string>
 
@@ -28,6 +29,8 @@
 
 namespace {
 
+  std::stringstream* GlobalTimeLog;
+
   sys::Path getTempDir() {
     sys::Path tempDir;
 
@@ -81,6 +84,11 @@
 
 namespace llvmc {
 
+// Used to implement -time option. External linkage is intentional.
+void AppendToGlobalTimeLog(const std::string& cmd, double time) {
+  *GlobalTimeLog << "# " << cmd << ' ' << time << '\n';
+}
+
 // Sometimes plugins want to condition on the value in argv[0].
 const char* ProgramName;
 
@@ -122,7 +130,19 @@
       throw std::runtime_error("no input files");
     }
 
-    return BuildTargets(graph, langMap);
+    if (Time) {
+      GlobalTimeLog = new std::stringstream;
+      GlobalTimeLog->precision(2);
+    }
+
+    int ret = BuildTargets(graph, langMap);
+
+    if (Time) {
+      llvm::errs() << GlobalTimeLog->str();
+      delete GlobalTimeLog;
+    }
+
+    return ret;
   }
   catch(llvmc::error_code& ec) {
     return ec.code();