[Support] Add ProcName to TimeTraceProfiler

This was hard-coded to "clang". This change allows it to to be used on
processes other than clang (such as lld).

This gets reported as clang-10 on Linux and clang.exe on Windows so
adapted test to accommodate this.

Differential Revision: https://reviews.llvm.org/D70950
diff --git a/clang/test/Driver/check-time-trace.cpp b/clang/test/Driver/check-time-trace.cpp
index 3c6a002..bff2c19 100644
--- a/clang/test/Driver/check-time-trace.cpp
+++ b/clang/test/Driver/check-time-trace.cpp
@@ -12,7 +12,7 @@
 // CHECK-NEXT: "pid":
 // CHECK-NEXT: "tid":
 // CHECK-NEXT: "ts":
-// CHECK: "name": "clang"
+// CHECK: "name": "clang{{.*}}"
 // CHECK: "name": "process_name"
 
 template <typename T>
diff --git a/clang/tools/driver/cc1_main.cpp b/clang/tools/driver/cc1_main.cpp
index 9e4f32d..efafed10 100644
--- a/clang/tools/driver/cc1_main.cpp
+++ b/clang/tools/driver/cc1_main.cpp
@@ -218,7 +218,7 @@
 
   if (Clang->getFrontendOpts().TimeTrace) {
     llvm::timeTraceProfilerInitialize(
-        Clang->getFrontendOpts().TimeTraceGranularity);
+        Clang->getFrontendOpts().TimeTraceGranularity, Argv0);
   }
   // --print-supported-cpus takes priority over the actual compilation.
   if (Clang->getFrontendOpts().PrintSupportedCPUs)
diff --git a/llvm/include/llvm/Support/TimeProfiler.h b/llvm/include/llvm/Support/TimeProfiler.h
index 8cc430d..2b51bba 100644
--- a/llvm/include/llvm/Support/TimeProfiler.h
+++ b/llvm/include/llvm/Support/TimeProfiler.h
@@ -19,7 +19,8 @@
 /// Initialize the time trace profiler.
 /// This sets up the global \p TimeTraceProfilerInstance
 /// variable to be the profiler instance.
-void timeTraceProfilerInitialize(unsigned TimeTraceGranularity);
+void timeTraceProfilerInitialize(unsigned TimeTraceGranularity,
+                                 StringRef ProcName);
 
 /// Cleanup the time trace profiler, if it was initialized.
 void timeTraceProfilerCleanup();
diff --git a/llvm/lib/Support/TimeProfiler.cpp b/llvm/lib/Support/TimeProfiler.cpp
index fc9ad16..6c99338 100644
--- a/llvm/lib/Support/TimeProfiler.cpp
+++ b/llvm/lib/Support/TimeProfiler.cpp
@@ -14,6 +14,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/JSON.h"
+#include "llvm/Support/Path.h"
 #include <cassert>
 #include <chrono>
 #include <string>
@@ -58,8 +59,8 @@
 };
 
 struct TimeTraceProfiler {
-  TimeTraceProfiler(unsigned TimeTraceGranularity = 0)
-      : StartTime(steady_clock::now()),
+  TimeTraceProfiler(unsigned TimeTraceGranularity = 0, StringRef ProcName = "")
+      : StartTime(steady_clock::now()), ProcName(ProcName),
         TimeTraceGranularity(TimeTraceGranularity) {}
 
   void begin(std::string Name, llvm::function_ref<std::string()> Detail) {
@@ -167,7 +168,7 @@
       J.attribute("ts", 0);
       J.attribute("ph", "M");
       J.attribute("name", "process_name");
-      J.attributeObject("args", [&] { J.attribute("name", "clang"); });
+      J.attributeObject("args", [&] { J.attribute("name", ProcName); });
     });
 
     J.arrayEnd();
@@ -179,15 +180,18 @@
   SmallVector<Entry, 128> Entries;
   StringMap<CountAndDurationType> CountAndTotalPerName;
   const TimePointType StartTime;
+  const std::string ProcName;
 
   // Minimum time granularity (in microseconds)
   const unsigned TimeTraceGranularity;
 };
 
-void timeTraceProfilerInitialize(unsigned TimeTraceGranularity) {
+void timeTraceProfilerInitialize(unsigned TimeTraceGranularity,
+                                 StringRef ProcName) {
   assert(TimeTraceProfilerInstance == nullptr &&
          "Profiler should not be initialized");
-  TimeTraceProfilerInstance = new TimeTraceProfiler(TimeTraceGranularity);
+  TimeTraceProfilerInstance = new TimeTraceProfiler(
+      TimeTraceGranularity, llvm::sys::path::filename(ProcName));
 }
 
 void timeTraceProfilerCleanup() {