CTest: Simplify std::chrono::duration<double> conversion to double

The ratio of ticks to seconds for this type is 1, so we can just use its
`count()` directly.  This also avoids converting through the integer
representation of `std::chrono::milliseconds`, which has a much smaller
allowed range.

Drop our `cmsysProcess_SetTimeout` wrapper as it is now very thin.

Source/CTest/cmCTestCoverageHandler.cxx

@@ -11,7 +11,6 @@
 #include "cmParseGTMCoverage.h"
 #include "cmParseJacocoCoverage.h"
 #include "cmParsePHPCoverage.h"
-#include "cmProcess.h"
 #include "cmSystemTools.h"
 #include "cmWorkingDirectory.h"
 #include "cmXMLWriter.h"
@@ -81,7 +80,7 @@ public:
 
     cmsysProcess_SetOption(this->Process, cmsysProcess_Option_HideWindow, 1);
     if (this->TimeOut >= std::chrono::duration<double>::zero()) {
-      cmsysProcess_SetTimeout(this->Process, this->TimeOut);
+      cmsysProcess_SetTimeout(this->Process, this->TimeOut.count());
     }
     cmsysProcess_Execute(this->Process);
     this->PipeState = cmsysProcess_GetState(this->Process);

Source/CTest/cmCTestRunTest.cxx

@@ -265,11 +265,7 @@ bool cmCTestRunTest::EndTest(size_t completed, size_t total, bool started)
 
   passed = this->TestResult.Status == cmCTestTestHandler::COMPLETED;
   char buf[1024];
-  sprintf(buf, "%6.2f sec",
-          double(std::chrono::duration_cast<std::chrono::milliseconds>(
-                   this->TestProcess->GetTotalTime())
-                   .count()) /
-            1000.0);
+  sprintf(buf, "%6.2f sec", this->TestProcess->GetTotalTime().count());
   cmCTestLog(this->CTest, HANDLER_OUTPUT, buf << "\n");
 
   if (outputTestErrorsToConsole) {
@@ -394,11 +390,7 @@ void cmCTestRunTest::ComputeWeightedCost()
 {
   double prev = static_cast<double>(this->TestProperties->PreviousRuns);
   double avgcost = static_cast<double>(this->TestProperties->Cost);
-  double current =
-    double(std::chrono::duration_cast<std::chrono::milliseconds>(
-             this->TestResult.ExecutionTime)
-             .count()) /
-    1000.0;
+  double current = this->TestResult.ExecutionTime.count();
 
   if (this->TestResult.Status == cmCTestTestHandler::COMPLETED) {
     this->TestProperties->Cost =

Source/CTest/cmCTestTestHandler.cxx

@@ -540,10 +540,8 @@ int cmCTestTestHandler::ProcessHandler()
       this->PrintLabelOrSubprojectSummary(false);
     }
     char realBuf[1024];
-    auto durationInMs = std::chrono::duration_cast<std::chrono::milliseconds>(
-                          clock_finish - clock_start)
-                          .count();
-    sprintf(realBuf, "%6.2f sec", static_cast<double>(durationInMs) / 1000.0);
+    std::chrono::duration<double> durationInSecs = clock_finish - clock_start;
+    sprintf(realBuf, "%6.2f sec", durationInSecs.count());
     cmCTestOptionalLog(this->CTest, HANDLER_OUTPUT,
                        "\nTotal Test time (real) = " << realBuf << "\n",
                        this->Quiet);
@@ -654,10 +652,7 @@ void cmCTestTestHandler::PrintLabelOrSubprojectSummary(bool doSubProject)
       // only use labels found in labels
       if (labels.find(l) != labels.end()) {
         labelTimes[l] +=
-          double(std::chrono::duration_cast<std::chrono::milliseconds>(
-                   result.ExecutionTime)
-                   .count()) /
-          1000.0 * result.Properties->Processors;
+          result.ExecutionTime.count() * result.Properties->Processors;
         ++labelCounts[l];
       }
     }
@@ -1327,11 +1322,7 @@ void cmCTestTestHandler::GenerateDartOutput(cmXMLWriter& xml)
       xml.StartElement("NamedMeasurement");
       xml.Attribute("type", "numeric/double");
       xml.Attribute("name", "Execution Time");
-      xml.Element("Value",
-                  double(std::chrono::duration_cast<std::chrono::milliseconds>(
-                           result.ExecutionTime)
-                           .count()) /
-                    1000.0);
+      xml.Element("Value", result.ExecutionTime.count());
       xml.EndElement(); // NamedMeasurement
       if (!result.Reason.empty()) {
         const char* reasonType = "Pass Reason";

Source/CTest/cmProcess.cxx

@@ -5,16 +5,6 @@
 #include "cmProcessOutput.h"
 #include <iostream>
 
-void cmsysProcess_SetTimeout(cmsysProcess* process,
-                             std::chrono::duration<double> timeout)
-{
-  cmsysProcess_SetTimeout(
-    process,
-    double(
-      std::chrono::duration_cast<std::chrono::milliseconds>(timeout).count()) /
-      1000.0);
-};
-
 cmProcess::cmProcess()
 {
   this->Process = nullptr;
@@ -59,7 +49,7 @@ bool cmProcess::StartProcess()
     cmsysProcess_SetWorkingDirectory(this->Process,
                                      this->WorkingDirectory.c_str());
   }
-  cmsysProcess_SetTimeout(this->Process, this->Timeout);
+  cmsysProcess_SetTimeout(this->Process, this->Timeout.count());
   cmsysProcess_SetOption(this->Process, cmsysProcess_Option_MergeOutput, 1);
   cmsysProcess_Execute(this->Process);
   return (cmsysProcess_GetState(this->Process) ==
@@ -115,10 +105,7 @@ int cmProcess::GetNextOutputLine(std::string& line,
 {
   cmProcessOutput processOutput(cmProcessOutput::UTF8);
   std::string strdata;
-  double waitTimeout =
-    double(
-      std::chrono::duration_cast<std::chrono::milliseconds>(timeout).count()) /
-    1000.0;
+  double waitTimeout = timeout.count();
   for (;;) {
     // Look for lines already buffered.
     if (this->Output.GetLine(line)) {
@@ -240,7 +227,7 @@ int cmProcess::ReportStatus()
 void cmProcess::ChangeTimeout(std::chrono::duration<double> t)
 {
   this->Timeout = t;
-  cmsysProcess_SetTimeout(this->Process, this->Timeout);
+  cmsysProcess_SetTimeout(this->Process, this->Timeout.count());
 }
 
 void cmProcess::ResetStartTime()

Source/CTest/cmProcess.h

@@ -10,13 +10,6 @@
 #include <string>
 #include <vector>
 
-/*
- * A wrapper function for cmsysProcess_SetTimeout that takes an
- * std::chrono::duration. For convenience only.
- */
-void cmsysProcess_SetTimeout(cmsysProcess* process,
-                             std::chrono::duration<double> timeout);
-
 /** \class cmProcess
  * \brief run a process with c++
  *

Source/cmCTest.cxx

@@ -50,7 +50,6 @@
 #include "cmGeneratedFileStream.h"
 #include "cmGlobalGenerator.h"
 #include "cmMakefile.h"
-#include "cmProcess.h"
 #include "cmProcessOutput.h"
 #include "cmState.h"
 #include "cmStateSnapshot.h"
@@ -998,7 +997,7 @@ int cmCTest::RunMakeCommand(const char* command, std::string& output,
   cmsysProcess_SetCommand(cp, &*argv.begin());
   cmsysProcess_SetWorkingDirectory(cp, dir);
   cmsysProcess_SetOption(cp, cmsysProcess_Option_HideWindow, 1);
-  cmsysProcess_SetTimeout(cp, timeout);
+  cmsysProcess_SetTimeout(cp, timeout.count());
   cmsysProcess_Execute(cp);
 
   // Initialize tick's
@@ -1186,7 +1185,7 @@ int cmCTest::RunTest(std::vector<const char*> argv, std::string* output,
     cmsysProcess_SetOption(cp, cmsysProcess_Option_HideWindow, 1);
   }
 
-  cmsysProcess_SetTimeout(cp, timeout);
+  cmsysProcess_SetTimeout(cp, timeout.count());
   cmsysProcess_Execute(cp);
 
   char* data;
@@ -2610,7 +2609,7 @@ bool cmCTest::RunCommand(std::vector<std::string> const& args,
   if (cmSystemTools::GetRunCommandHideConsole()) {
     cmsysProcess_SetOption(cp, cmsysProcess_Option_HideWindow, 1);
   }
-  cmsysProcess_SetTimeout(cp, timeout);
+  cmsysProcess_SetTimeout(cp, timeout.count());
   cmsysProcess_Execute(cp);
 
   std::vector<char> tempOutput;