prop_sf/OBJECT_NAME: support custom object names

Projects which ship object files as artifacts may want to control the
object names as much as possible. Support setting explicit object names
as source file properties to support such use cases.

Source/cmLocalGenerator.cxx

@@ -25,6 +25,7 @@
 #include "cmsys/RegularExpression.hxx"
 
 #include "cmAlgorithms.h"
+#include "cmCMakePath.h"
 #include "cmComputeLinkInformation.h"
 #include "cmCryptoHash.h"
 #include "cmCustomCommand.h"
@@ -4237,6 +4238,94 @@ std::string cmLocalGenerator::GetRelativeSourceFileName(
   return objectName;
 }
 
+std::string cmLocalGenerator::GetCustomObjectFileName(
+  cmSourceFile const& source) const
+{
+  if (!this->GetGlobalGenerator()->SupportsCustomObjectNames()) {
+    return std::string{};
+  }
+
+  if (auto objName = source.GetProperty("OBJECT_NAME")) {
+    cmGeneratorExpression ge(*this->GetCMakeInstance());
+    auto cge = ge.Parse(objName);
+    static std::string const INVALID_GENEX =
+      "_cmake_invalid_object_name_genex";
+    static std::string const INVALID_VALUE =
+      "_cmake_invalid_object_name_value";
+
+    if (!cge) {
+      this->Makefile->IssueMessage(
+        MessageType::FATAL_ERROR,
+        cmStrCat("The  \"OBJECT_NAME\" property for\n  ", source.GetFullPath(),
+                 "\nis not a valid generator expression (", objName, ")."));
+      return INVALID_GENEX;
+    }
+    if (cge->GetHadHeadSensitiveCondition()) {
+      // Not reachable; all target-sensitive  genexes actually fail to parse.
+      this->Makefile->IssueMessage(
+        MessageType::FATAL_ERROR,
+        cmStrCat("The  \"OBJECT_NAME\" property for\n  ", source.GetFullPath(),
+                 "\ncontains a condition that queries the consuming target "
+                 "which is not supported (",
+                 objName, ")."));
+      return INVALID_GENEX;
+    }
+    if (cge->GetHadLinkLanguageSensitiveCondition()) {
+      // Not reachable; all target-sensitive  genexes actually fail to parse.
+      this->Makefile->IssueMessage(
+        MessageType::FATAL_ERROR,
+        cmStrCat("The  \"OBJECT_NAME\" property for\n  ", source.GetFullPath(),
+                 "\ncontains a condition that queries the link language "
+                 "which is not supported (",
+                 objName, ")."));
+      return INVALID_GENEX;
+    }
+
+    auto objNameValue = cge->Evaluate(this, "");
+    if (cge->GetHadContextSensitiveCondition()) {
+      this->Makefile->IssueMessage(
+        MessageType::FATAL_ERROR,
+        cmStrCat("The  \"OBJECT_NAME\" property for\n  ", source.GetFullPath(),
+                 "\ncontains a context-sensitive condition which is not "
+                 "supported (",
+                 objName, ")."));
+      return INVALID_GENEX;
+    }
+
+    // Skip if it evaluates to empty.
+    if (!objNameValue.empty()) {
+      cmCMakePath objNamePath = objNameValue;
+      // Verify that it is a relative path.
+      if (objNamePath.IsAbsolute()) {
+        this->Makefile->IssueMessage(
+          MessageType::FATAL_ERROR,
+          cmStrCat(
+            "The  \"OBJECT_NAME\" property for\n  ", source.GetFullPath(),
+            "\nresolves to an absolute path which is not supported:\n  ",
+            objNameValue));
+        return INVALID_VALUE;
+      }
+      auto isInvalidComponent = [](cmCMakePath const& component) -> bool {
+        return component == ".."_s;
+      };
+      // Verify that it contains no `..` components.
+      if (std::any_of(objNamePath.begin(), objNamePath.end(),
+                      isInvalidComponent)) {
+        this->Makefile->IssueMessage(
+          MessageType::FATAL_ERROR,
+          cmStrCat("The  \"OBJECT_NAME\" property for\n  ",
+                   source.GetFullPath(), "\ncontains an invalid component (",
+                   objNameValue, ")."));
+        return INVALID_VALUE;
+      }
+
+      return objNameValue;
+    }
+  }
+
+  return std::string{};
+}
+
 std::string cmLocalGenerator::GetObjectFileNameWithoutTarget(
   cmSourceFile const& source, std::string const& dir_max,
   bool* hasSourceExtension, char const* customOutputExtension,
@@ -4247,6 +4336,17 @@ std::string cmLocalGenerator::GetObjectFileNameWithoutTarget(
     useShortObjectNames = *forceShortObjectName;
   }
 
+  if (!useShortObjectNames) {
+    auto customName = this->GetCustomObjectFileName(source);
+    if (!customName.empty()) {
+      auto ext = this->GlobalGenerator->GetLanguageOutputExtension(source);
+      if (customOutputExtension) {
+        ext = *customOutputExtension;
+      }
+      return cmStrCat(customName, ext);
+    }
+  }
+
   // This can return an absolute path in the case where source is
   // not relative to the current source or binary directories
   std::string objectName = this->GetRelativeSourceFileName(source);