[slangc] generate an error when `-entry` is not specified for targets that require them. (#3679)

* [slangc] generate an error when `-entry` is not specified for targets that require them.

* Fix.

* Fix.

1 files changed, 7 insertions, 1 deletions

diff --git a/source/slang/slang-options.cpp b/source/slang/slang-options.cpp
index 5e009c46e..6b56d5600 100644
--- a/source/slang/slang-options.cpp
+++ b/source/slang/slang-options.cpp
@@ -2822,8 +2822,14 @@ SlangResult OptionsParser::_parse(
                         if (getCurrentTarget()->optionSet.shouldEmitSPIRVDirectly())
                         {
                             rawOutput.isWholeProgram = true;
+                            break;
                         }
-                        break;
+                        else if (m_rawEntryPoints.getCount() != 0)
+                        {
+                            rawOutput.entryPointIndex = (int)m_rawEntryPoints.getCount() - 1;
+                            break;
+                        }
+                        [[fallthrough]];
                     default:
                         m_sink->diagnose(SourceLoc(), Diagnostics::cannotMatchOutputFileToEntryPoint, rawOutput.path);
                         break;