TestGenerator: Record support file and line where test was added

Add internal test properties that ctest can use to report where
the test was added in CMake code.

Source/CTest/cmCTestTestHandler.cxx

@@ -2147,6 +2147,32 @@ bool cmCTestTestHandler::SetTestsProperties(
     for (std::string const& t : tests) {
       for (cmCTestTestProperties& rt : this->TestList) {
         if (t == rt.Name) {
+          if (key == "_BACKTRACE_TRIPLES") {
+            std::vector<std::string> triples;
+            // allow empty args in the triples
+            cmSystemTools::ExpandListArgument(val, triples, true);
+
+            // Ensure we have complete triples otherwise the data is corrupt.
+            if (triples.size() % 3 == 0) {
+              cmState state;
+              rt.Backtrace = cmListFileBacktrace(state.CreateBaseSnapshot());
+
+              // the first entry represents the top of the trace so we need to
+              // reconstruct the backtrace in reverse
+              for (size_t i = triples.size(); i >= 3; i -= 3) {
+                cmListFileContext fc;
+                fc.FilePath = triples[i - 3];
+                long line = 0;
+                if (!cmSystemTools::StringToLong(triples[i - 2].c_str(),
+                                                 &line)) {
+                  line = 0;
+                }
+                fc.Line = line;
+                fc.Name = triples[i - 1];
+                rt.Backtrace = rt.Backtrace.Push(fc);
+              }
+            }
+          }
           if (key == "WILL_FAIL") {
             rt.WillFail = cmSystemTools::IsOn(val);
           }

Source/CTest/cmCTestTestHandler.h

@@ -7,6 +7,7 @@
 
 #include "cmCTestGenericHandler.h"
 #include "cmDuration.h"
+#include "cmListFileCache.h"
 
 #include "cmsys/RegularExpression.hxx"
 #include <chrono>
@@ -141,6 +142,8 @@ public:
     std::set<std::string> FixturesCleanup;
     std::set<std::string> FixturesRequired;
     std::set<std::string> RequireSuccessDepends;
+    // Private test generator properties used to track backtraces
+    cmListFileBacktrace Backtrace;
   };
 
   struct cmCTestTestResult

Source/cmTestGenerator.cxx

@@ -7,14 +7,16 @@
 
 #include "cmGeneratorExpression.h"
 #include "cmGeneratorTarget.h"
+#include "cmListFileCache.h"
 #include "cmLocalGenerator.h"
 #include "cmOutputConverter.h"
 #include "cmProperty.h"
-#include "cmPropertyMap.h"
 #include "cmStateTypes.h"
 #include "cmSystemTools.h"
 #include "cmTest.h"
 
+class cmPropertyMap;
+
 cmTestGenerator::cmTestGenerator(
   cmTest* test, std::vector<std::string> const& configurations)
   : cmScriptGenerator("CTEST_CONFIGURATION_TYPE", configurations)
@@ -121,16 +123,15 @@ void cmTestGenerator::GenerateScriptForConfig(std::ostream& os,
 
   // Output properties for the test.
   cmPropertyMap& pm = this->Test->GetProperties();
-  if (!pm.empty()) {
-    os << indent << "set_tests_properties(" << this->Test->GetName()
-       << " PROPERTIES ";
-    for (auto const& i : pm) {
-      os << " " << i.first << " "
-         << cmOutputConverter::EscapeForCMake(
-              ge.Parse(i.second.GetValue())->Evaluate(this->LG, config));
-    }
-    os << ")" << std::endl;
+  os << indent << "set_tests_properties(" << this->Test->GetName()
+     << " PROPERTIES ";
+  for (auto const& i : pm) {
+    os << " " << i.first << " "
+       << cmOutputConverter::EscapeForCMake(
+            ge.Parse(i.second.GetValue())->Evaluate(this->LG, config));
   }
+  this->GenerateInternalProperties(os);
+  os << ")" << std::endl;
 }
 
 void cmTestGenerator::GenerateScriptNoConfig(std::ostream& os, Indent indent)
@@ -179,13 +180,37 @@ void cmTestGenerator::GenerateOldStyle(std::ostream& fout, Indent indent)
 
   // Output properties for the test.
   cmPropertyMap& pm = this->Test->GetProperties();
-  if (!pm.empty()) {
-    fout << indent << "set_tests_properties(" << this->Test->GetName()
-         << " PROPERTIES ";
-    for (auto const& i : pm) {
-      fout << " " << i.first << " "
-           << cmOutputConverter::EscapeForCMake(i.second.GetValue());
-    }
-    fout << ")" << std::endl;
+  fout << indent << "set_tests_properties(" << this->Test->GetName()
+       << " PROPERTIES ";
+  for (auto const& i : pm) {
+    fout << " " << i.first << " "
+         << cmOutputConverter::EscapeForCMake(i.second.GetValue());
   }
+  this->GenerateInternalProperties(fout);
+  fout << ")" << std::endl;
+}
+
+void cmTestGenerator::GenerateInternalProperties(std::ostream& os)
+{
+  cmListFileBacktrace bt = this->Test->GetBacktrace();
+  if (bt.Empty()) {
+    return;
+  }
+
+  os << " "
+     << "_BACKTRACE_TRIPLES"
+     << " \"";
+
+  bool prependTripleSeparator = false;
+  while (!bt.Empty()) {
+    const auto& entry = bt.Top();
+    if (prependTripleSeparator) {
+      os << ";";
+    }
+    os << entry.FilePath << ";" << entry.Line << ";" << entry.Name;
+    bt = bt.Pop();
+    prependTripleSeparator = true;
+  }
+
+  os << "\"";
 }

Source/cmTestGenerator.h

@@ -35,6 +35,9 @@ public:
 
   cmTest* GetTest() const;
 
+private:
+  void GenerateInternalProperties(std::ostream& os);
+
 protected:
   void GenerateScriptConfigs(std::ostream& os, Indent indent) override;
   void GenerateScriptActions(std::ostream& os, Indent indent) override;