From 49576cf1df618609be4aa1000749ad087c143df0 Mon Sep 17 00:00:00 2001
From: John Drouhard <john@drouhard.dev>
Date: Thu, 9 Jan 2025 20:34:42 -0600
Subject: [PATCH] ctest: Allow arbitrary characters in test names of
 CTestCostData.txt

This changes the way lines in CTestCostData.txt are parsed to allow for
spaces in the test name.

It does so by looking for space characters from the end; and once two
have been found, assumes everything from the beginning up to that
second-to-last-space is the test name.

Additionally, parsing the file should be much more efficient since there
is no string or vector heap allocation per line. The std::string used by
the parse function to convert the int and float should be within most
standard libraries' small string optimization.

Fixes: #26594

Upstream-Status: Backport [4.0.0, 040da7d83216ace59710407e8ce35d5fd38e1340]
Signed-off-by: Moritz Haase <Moritz.Haase@bmw.de>
---
 Source/CTest/cmCTestMultiProcessHandler.cxx | 80 +++++++++++++++------
 Source/CTest/cmCTestMultiProcessHandler.h   |  3 +-
 Tests/CTestTestScheduler/CMakeLists.txt     |  4 +-
 3 files changed, 64 insertions(+), 23 deletions(-)

diff --git a/Source/CTest/cmCTestMultiProcessHandler.cxx b/Source/CTest/cmCTestMultiProcessHandler.cxx
index ca07a081eafced40697d82b08c0e2a504939fc4d..59a101454b84367d219e79a01ff72702df0dfa7f 100644
--- a/Source/CTest/cmCTestMultiProcessHandler.cxx
+++ b/Source/CTest/cmCTestMultiProcessHandler.cxx
@@ -20,6 +20,7 @@
 
 #include <cm/memory>
 #include <cm/optional>
+#include <cm/string_view>
 #include <cmext/algorithm>
 
 #include <cm3p/json/value.h>
@@ -43,6 +44,51 @@
 #include "cmUVSignalHackRAII.h" // IWYU pragma: keep
 #include "cmWorkingDirectory.h"
 
+namespace {
+
+struct CostEntry
+{
+  cm::string_view name;
+  int prevRuns;
+  float cost;
+};
+
+cm::optional<CostEntry> splitCostLine(cm::string_view line)
+{
+  std::string part;
+  cm::string_view::size_type pos1 = line.size();
+  cm::string_view::size_type pos2 = line.find_last_of(' ', pos1);
+  auto findNext = [line, &part, &pos1, &pos2]() -> bool {
+    if (pos2 != cm::string_view::npos) {
+      cm::string_view sub = line.substr(pos2 + 1, pos1 - pos2 - 1);
+      part.assign(sub.begin(), sub.end());
+      pos1 = pos2;
+      if (pos1 > 0) {
+        pos2 = line.find_last_of(' ', pos1 - 1);
+      }
+      return true;
+    }
+    return false;
+  };
+
+  // parse the cost
+  if (!findNext()) {
+    return cm::nullopt;
+  }
+  float cost = static_cast<float>(atof(part.c_str()));
+
+  // parse the previous runs
+  if (!findNext()) {
+    return cm::nullopt;
+  }
+  int prev = atoi(part.c_str());
+
+  // from start to the last found space is the name
+  return CostEntry{ line.substr(0, pos1), prev, cost };
+}
+
+}
+
 namespace cmsys {
 class RegularExpression;
 }
@@ -697,24 +743,21 @@ void cmCTestMultiProcessHandler::UpdateCostData()
       if (line == "---") {
         break;
       }
-      std::vector<std::string> parts = cmSystemTools::SplitString(line, ' ');
       // Format: <name> <previous_runs> <avg_cost>
-      if (parts.size() < 3) {
+      cm::optional<CostEntry> entry = splitCostLine(line);
+      if (!entry) {
         break;
       }
 
-      std::string name = parts[0];
-      int prev = atoi(parts[1].c_str());
-      float cost = static_cast<float>(atof(parts[2].c_str()));
-
-      int index = this->SearchByName(name);
+      int index = this->SearchByName(entry->name);
       if (index == -1) {
         // This test is not in memory. We just rewrite the entry
-        fout << name << " " << prev << " " << cost << "\n";
+        fout << entry->name << " " << entry->prevRuns << " " << entry->cost
+             << "\n";
       } else {
         // Update with our new average cost
-        fout << name << " " << this->Properties[index]->PreviousRuns << " "
-             << this->Properties[index]->Cost << "\n";
+        fout << entry->name << " " << this->Properties[index]->PreviousRuns
+             << " " << this->Properties[index]->Cost << "\n";
         temp.erase(index);
       }
     }
@@ -750,28 +793,25 @@ void cmCTestMultiProcessHandler::ReadCostData()
         break;
       }
 
-      std::vector<std::string> parts = cmSystemTools::SplitString(line, ' ');
+      // Format: <name> <previous_runs> <avg_cost>
+      cm::optional<CostEntry> entry = splitCostLine(line);
 
       // Probably an older version of the file, will be fixed next run
-      if (parts.size() < 3) {
+      if (!entry) {
         fin.close();
         return;
       }
 
-      std::string name = parts[0];
-      int prev = atoi(parts[1].c_str());
-      float cost = static_cast<float>(atof(parts[2].c_str()));
-
-      int index = this->SearchByName(name);
+      int index = this->SearchByName(entry->name);
       if (index == -1) {
         continue;
       }
 
-      this->Properties[index]->PreviousRuns = prev;
+      this->Properties[index]->PreviousRuns = entry->prevRuns;
       // When not running in parallel mode, don't use cost data
       if (this->ParallelLevel > 1 && this->Properties[index] &&
           this->Properties[index]->Cost == 0) {
-        this->Properties[index]->Cost = cost;
+        this->Properties[index]->Cost = entry->cost;
       }
     }
     // Next part of the file is the failed tests
@@ -784,7 +824,7 @@ void cmCTestMultiProcessHandler::ReadCostData()
   }
 }
 
-int cmCTestMultiProcessHandler::SearchByName(std::string const& name)
+int cmCTestMultiProcessHandler::SearchByName(cm::string_view name)
 {
   int index = -1;
 
diff --git a/Source/CTest/cmCTestMultiProcessHandler.h b/Source/CTest/cmCTestMultiProcessHandler.h
index 3b4e9c59ad1871168d8528be0586831e2416ae36..8d33dabcf0d9fc6e11459105c65eadaa1de33e42 100644
--- a/Source/CTest/cmCTestMultiProcessHandler.h
+++ b/Source/CTest/cmCTestMultiProcessHandler.h
@@ -12,6 +12,7 @@
 #include <vector>
 
 #include <cm/optional>
+#include <cm/string_view>
 
 #include <cm3p/uv.h>
 
@@ -113,7 +114,7 @@ protected:
   void UpdateCostData();
   void ReadCostData();
   // Return index of a test based on its name
-  int SearchByName(std::string const& name);
+  int SearchByName(cm::string_view name);
 
   void CreateTestCostList();
 
diff --git a/Tests/CTestTestScheduler/CMakeLists.txt b/Tests/CTestTestScheduler/CMakeLists.txt
index 91d565d4020aafda6d49462cd8616d168d5844b6..daf6ce2b23d8c048334ae1047759130b246dccef 100644
--- a/Tests/CTestTestScheduler/CMakeLists.txt
+++ b/Tests/CTestTestScheduler/CMakeLists.txt
@@ -1,9 +1,9 @@
-cmake_minimum_required (VERSION 3.5)
+cmake_minimum_required(VERSION 3.19)
 project (CTestTestScheduler)
 include (CTest)
 
 add_executable (Sleep sleep.c)
 
 foreach (time RANGE 1 4)
-  add_test (TestSleep${time} Sleep ${time})
+  add_test ("TestSleep ${time}" Sleep ${time})
 endforeach ()
