Custom rule: ensure user's callbacks are executed during config step

Help/command/add_custom_rule.rst

@@ -178,9 +178,9 @@ Generating Files
     usually emitted by the custom command itself.
 
   ``CONFIGURATOR``
-    Specify one or two CMake functions which will be called at the generation
-    step, in the context of the file set directory, before the effective
-    instantiation and custom commands definition.
+    Specify one or two CMake functions which will be called at the
+    configuration step, in the context of the file set directory, before the
+    effective instantiation and custom commands definition.
 
     .. note::
 
@@ -314,8 +314,9 @@ Derived Rule
     Specify the rule from which this new rule will inherit.
 
   ``CONFIGURATOR``
-    Specify one or two CMake functions which will be called at the generation
-    step before the effective instantiation and custom commands definition.
+    Specify one or two CMake functions which will be called at the
+    configuration step, in the context of the file set directory, before the
+    effective instantiation and custom commands definition.
 
     .. note::
 

Source/cmGlobalGenerator.cxx

@@ -1544,6 +1544,8 @@ void cmGlobalGenerator::Configure()
 
   this->ReserveGlobalTargetCodegen();
 
+  this->ConfigureRules();
+
   // update the cache entry for the number of local generators, this is used
   // for progress
   this->GetCMakeInstance()->AddCacheEntry(
@@ -1555,8 +1557,6 @@ void cmGlobalGenerator::CreateGenerationObjects(TargetTypes targetTypes)
 {
   this->CreateLocalGenerators();
 
-  this->CreateCustomCommandsFromRules();
-
   // Commit side effects only if we are actually generating
   if (targetTypes == TargetTypes::AllTargets) {
     this->CheckTargetProperties();
@@ -2335,58 +2335,6 @@ cmGlobalGenerator::CreateMSVC60LinkLineComputer(
     cm::make_unique<cmMSVC60LinkLineComputer>(outputConverter, stateDir));
 }
 
-void cmGlobalGenerator::CreateCustomCommandsFromRules()
-{
-  for (unsigned int i = 0; i < this->LocalGenerators.size(); ++i) {
-    cmMakefile* mf = this->Makefiles[i].get();
-    cmLocalGenerator* lg = this->LocalGenerators[i].get();
-    for (auto& item : mf->GetTargets()) {
-      cmTarget& target = item.second;
-      for (auto const& fsName : target.GetAllFileSetNames(
-             cm::FileSetMetadata::FileSetDomain::RULE)) {
-        cmFileSet const* fileSet = target.GetFileSet(fsName);
-        cmRule const* rule =
-          fileSet->GetMakefile()->FindRuleToUse(fileSet->GetType());
-        if (!rule) {
-          continue;
-        }
-
-        // generated files by the custom command are stored in a file set
-        cmFileSet* outFileSet = rule->GetOutputFileSet(&target, fileSet);
-        if (!outFileSet) {
-          continue;
-        }
-
-        cmRule::PatternSet fileSetPatterns;
-        if (!rule->Instantiate(&target, fileSet, outFileSet,
-                               fileSetPatterns)) {
-          continue;
-        }
-
-        for (auto const& files : fileSet->GetFileEntries()) {
-          for (auto const& file :
-               cmList{ cm::remove_BT(files), cmList::EmptyElements::No }) {
-            cmSourceFile* source = mf->GetOrCreateSource(file);
-            source->ResolveFullPath();
-
-            cmRule::PatternSet sourcePatterns{ fileSetPatterns };
-            if (!rule->Instantiate(&target, fileSet, outFileSet, source,
-                                   sourcePatterns)) {
-              continue;
-            }
-
-            auto genRule = cm::make_unique<cmGeneratorRule>(
-              rule, &target, fileSet, outFileSet, source, sourcePatterns);
-            auto cc = genRule->Generate(outFileSet);
-            lg->AddGeneratorRule(std::move(genRule));
-            mf->AddCustomCommandToOutput(std::move(cc));
-          }
-        }
-      }
-    }
-  }
-}
-
 void cmGlobalGenerator::FinalizeTargetConfiguration()
 {
   std::vector<std::string> const langs =
@@ -3905,6 +3853,61 @@ void cmGlobalGenerator::ReserveGlobalTargetCodegen()
   }
 }
 
+void cmGlobalGenerator::ConfigureRules()
+{
+  for (auto const& mf : this->Makefiles) {
+    for (auto& item : mf->GetTargets()) {
+      cmTarget& target = item.second;
+      for (auto const& fsName : target.GetAllFileSetNames(
+             cm::FileSetMetadata::FileSetDomain::RULE)) {
+        cmFileSet const* fileSet = target.GetFileSet(fsName);
+        cmRule const* rule =
+          fileSet->GetMakefile()->FindRuleToUse(fileSet->GetType());
+        if (!rule) {
+          continue;
+        }
+
+        // generated files by the custom command are stored in a file set
+        cmFileSet* outFileSet = rule->GetOutputFileSet(&target, fileSet);
+        if (!outFileSet) {
+          continue;
+        }
+
+        cmRule::PatternSet fileSetPatterns;
+        if (!rule->Instantiate(&target, fileSet, outFileSet,
+                               fileSetPatterns)) {
+          continue;
+        }
+
+        for (auto const& files : fileSet->GetFileEntries()) {
+          for (auto const& file :
+               cmList{ cm::remove_BT(files), cmList::EmptyElements::No }) {
+            cmSourceFile* source = mf->GetOrCreateSource(file);
+            source->ResolveFullPath();
+
+            cmRule::PatternSet sourcePatterns{ fileSetPatterns };
+            if (!rule->Instantiate(&target, fileSet, outFileSet, source,
+                                   sourcePatterns)) {
+              continue;
+            }
+
+            mf->AddGeneratorAction(
+              [rule, &target, fileSet, outFileSet, source, sourcePatterns](
+                cmLocalGenerator& lg, cmListFileBacktrace const&) {
+                auto genRule = cm::make_unique<cmGeneratorRule>(
+                  rule, &target, fileSet, outFileSet, source, sourcePatterns);
+                auto cc = genRule->Generate(outFileSet);
+                lg.AddGeneratorRule(std::move(genRule));
+                detail::AddCustomCommandToOutput(
+                  lg, cmCommandOrigin::Generator, std::move(cc), false);
+              });
+          }
+        }
+      }
+    }
+  }
+}
+
 bool cmGlobalGenerator::CheckCMP0171() const
 {
   return this->AllowGlobalTargetCodegen;

Source/cmGlobalGenerator.h

@@ -227,9 +227,6 @@ public:
 
   virtual bool InspectConfigTypeVariables() { return true; }
 
-  // Produce custom commands for file sets attached to a custom rule
-  void CreateCustomCommandsFromRules();
-
   enum class CxxModuleSupportQuery
   {
     // Support is expected at the call site.
@@ -940,6 +937,10 @@ protected:
 
   void ReserveGlobalTargetCodegen();
 
+  // Execute user's callbacks and produce custom commands for file sets
+  // attached to a custom rule
+  void ConfigureRules();
+
   std::string FindMakeProgramFile;
   std::string ConfiguredFilesPath;
   cmake* CMakeInstance;

Tests/RunCMake/CustomRule/RuleProperties2-stderr.txt

@@ -20,9 +20,3 @@ Call Stack \(most recent call first\):
 CMake Error in CMakeLists\.txt:
   Erroneous execution of the CONFIGURATOR "configurator2", from the RULE
   "foo2", for the FILE_SET "fs2" of TARGET "foo"\.
-
-
-CMake Error at RuleProperties2\.cmake:[0-9]+ \(add_library\):
-  No SOURCES given to target: foo
-Call Stack \(most recent call first\):
-  CMakeLists\.txt:[0-9]+ \(include\)

Tests/RunCMake/GenEx-RULE_PROPERTY/self-reference-stderr.txt

@@ -1,4 +1,4 @@
-CMake Error in CMakeLists\.txt:
+CMake Error:
   Error evaluating generator expression:
 
     \$<RULE_PROPERTY:foo_[0-9]+,COMPILE_OPTIONS>