Merge topic 'compile-only-genex'

c42630ee62 cmGeneratorExpressionNode: implement `COMPILE_ONLY` genex
0fb923c460 cmGeneratorExpressionNode: implement `COMPILE_ONLY` genex

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !8411

6 files changed, 56 insertions, 2 deletions

diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 2ad2b472ea..22276ae508 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -735,6 +735,22 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
     lastPos = nameStartPos + libName.size() + 1;
   }
 
+  while (errorString.empty() &&
+         (pos = input.find("$<COMPILE_ONLY:", lastPos)) != std::string::npos) {
+    std::string::size_type nameStartPos = pos + cmStrLen("$<COMPILE_ONLY:");
+    std::string::size_type endPos = input.find('>', nameStartPos);
+    if (endPos == std::string::npos) {
+      errorString = "$<COMPILE_ONLY:...> expression incomplete";
+      break;
+    }
+    std::string libName = input.substr(nameStartPos, endPos - nameStartPos);
+    if (cmGeneratorExpression::IsValidTargetName(libName) &&
+        this->AddTargetNamespace(libName, target, lg)) {
+      input.replace(nameStartPos, endPos - nameStartPos, libName);
+    }
+    lastPos = nameStartPos + libName.size() + 1;
+  }
+
   this->ReplaceInstallPrefix(input);
 
   if (!errorString.empty()) {
diff --git a/Source/cmGeneratorExpressionDAGChecker.cxx b/Source/cmGeneratorExpressionDAGChecker.cxx
index 82a6c57dc0..d51dbd08f5 100644
--- a/Source/cmGeneratorExpressionDAGChecker.cxx
+++ b/Source/cmGeneratorExpressionDAGChecker.cxx
@@ -27,6 +27,7 @@ cmGeneratorExpressionDAGChecker::cmGeneratorExpressionDAGChecker(
   , Content(content)
   , Backtrace(std::move(backtrace))
   , TransitivePropertiesOnly(false)
+  , CMP0131(false)
 {
   this->Initialize();
 }
@@ -41,6 +42,7 @@ cmGeneratorExpressionDAGChecker::cmGeneratorExpressionDAGChecker(
   , Content(content)
   , Backtrace()
   , TransitivePropertiesOnly(false)
+  , CMP0131(false)
 {
   this->Initialize();
 }
@@ -143,6 +145,12 @@ bool cmGeneratorExpressionDAGChecker::GetTransitivePropertiesOnly() const
   return this->Top()->TransitivePropertiesOnly;
 }
 
+bool cmGeneratorExpressionDAGChecker::GetTransitivePropertiesOnlyCMP0131()
+  const
+{
+  return this->Top()->CMP0131;
+}
+
 bool cmGeneratorExpressionDAGChecker::EvaluatingGenexExpression() const
 {
   return cmHasLiteralPrefix(this->Property, "TARGET_GENEX_EVAL:") ||
diff --git a/Source/cmGeneratorExpressionDAGChecker.h b/Source/cmGeneratorExpressionDAGChecker.h
index df1e0050c2..1919b014e5 100644
--- a/Source/cmGeneratorExpressionDAGChecker.h
+++ b/Source/cmGeneratorExpressionDAGChecker.h
@@ -90,6 +90,9 @@ struct cmGeneratorExpressionDAGChecker
   bool GetTransitivePropertiesOnly() const;
   void SetTransitivePropertiesOnly() { this->TransitivePropertiesOnly = true; }
 
+  bool GetTransitivePropertiesOnlyCMP0131() const;
+  void SetTransitivePropertiesOnlyCMP0131() { this->CMP0131 = true; }
+
   cmGeneratorExpressionDAGChecker const* Top() const;
   cmGeneratorTarget const* TopTarget() const;
 
@@ -105,4 +108,5 @@ private:
   const cmListFileBacktrace Backtrace;
   Result CheckResult;
   bool TransitivePropertiesOnly;
+  bool CMP0131;
 };
diff --git a/Source/cmGeneratorExpressionNode.cxx b/Source/cmGeneratorExpressionNode.cxx
index 4f5a663dba..bb4fc7e271 100644
--- a/Source/cmGeneratorExpressionNode.cxx
+++ b/Source/cmGeneratorExpressionNode.cxx
@@ -2046,6 +2046,28 @@ static const VersionNode<cmSystemTools::OP_LESS> versionLessNode;
 static const VersionNode<cmSystemTools::OP_LESS_EQUAL> versionLessEqNode;
 static const VersionNode<cmSystemTools::OP_EQUAL> versionEqualNode;
 
+static const struct CompileOnlyNode : public cmGeneratorExpressionNode
+{
+  CompileOnlyNode() {} // NOLINT(modernize-use-equals-default)
+
+  std::string Evaluate(
+    const std::vector<std::string>& parameters,
+    cmGeneratorExpressionContext* context,
+    const GeneratorExpressionContent* content,
+    cmGeneratorExpressionDAGChecker* dagChecker) const override
+  {
+    if (!dagChecker) {
+      reportError(context, content->GetOriginalExpression(),
+                  "$<COMPILE_ONLY:...> may only be used for linking");
+      return std::string();
+    }
+    if (dagChecker->GetTransitivePropertiesOnly()) {
+      return parameters.front();
+    }
+    return std::string{};
+  }
+} compileOnlyNode;
+
 static const struct LinkOnlyNode : public cmGeneratorExpressionNode
 {
   LinkOnlyNode() {} // NOLINT(modernize-use-equals-default)
@@ -2061,7 +2083,7 @@ static const struct LinkOnlyNode : public cmGeneratorExpressionNode
                   "$<LINK_ONLY:...> may only be used for linking");
       return std::string();
     }
-    if (!dagChecker->GetTransitivePropertiesOnly()) {
+    if (!dagChecker->GetTransitivePropertiesOnlyCMP0131()) {
       return parameters.front();
     }
     return std::string();
@@ -4501,6 +4523,7 @@ const cmGeneratorExpressionNode* cmGeneratorExpressionNode::GetNode(
     { "BUILD_LOCAL_INTERFACE", &buildLocalInterfaceNode },
     { "INSTALL_PREFIX", &installPrefixNode },
     { "JOIN", &joinNode },
+    { "COMPILE_ONLY", &compileOnlyNode },
     { "LINK_ONLY", &linkOnlyNode },
     { "COMPILE_LANG_AND_ID", &languageAndIdNode },
     { "COMPILE_LANGUAGE", &languageNode },
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 897619cbfa..28ba60f4ed 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -6791,6 +6791,7 @@ void cmGeneratorTarget::ExpandLinkItems(
   // requirements.
   if (interfaceFor == LinkInterfaceFor::Usage) {
     dagChecker.SetTransitivePropertiesOnly();
+    dagChecker.SetTransitivePropertiesOnlyCMP0131();
   }
   cmMakefile const* mf = this->LocalGenerator->GetMakefile();
   LookupLinkItemScope scope{ this->LocalGenerator };
@@ -8228,6 +8229,7 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
     // The $<LINK_ONLY> expression may be used to specify link dependencies
     // that are otherwise excluded from usage requirements.
     if (implFor == LinkInterfaceFor::Usage) {
+      dagChecker.SetTransitivePropertiesOnly();
       switch (this->GetPolicyStatusCMP0131()) {
         case cmPolicies::WARN:
         case cmPolicies::OLD:
@@ -8235,7 +8237,7 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
         case cmPolicies::REQUIRED_IF_USED:
         case cmPolicies::REQUIRED_ALWAYS:
         case cmPolicies::NEW:
-          dagChecker.SetTransitivePropertiesOnly();
+          dagChecker.SetTransitivePropertiesOnlyCMP0131();
           break;
       }
     }
diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLinkLibrariesCommand.cxx
index 0b123b2d61..03d7c9fea9 100644
--- a/Source/cmTargetLinkLibrariesCommand.cxx
+++ b/Source/cmTargetLinkLibrariesCommand.cxx
@@ -552,6 +552,7 @@ bool TLL::HandleLibrary(ProcessingState currentProcessingState,
       currentProcessingState == ProcessingPlainPrivateInterface) {
     if (this->Target->GetType() == cmStateEnums::STATIC_LIBRARY ||
         this->Target->GetType() == cmStateEnums::OBJECT_LIBRARY) {
+      // TODO: Detect and no-op `$<COMPILE_ONLY>` genexes here.
       std::string configLib =
         this->Target->GetDebugGeneratorExpressions(lib, llt);
       if (cmGeneratorExpression::IsValidTargetName(lib) ||