Add FIR tests for header compilation.

^KT-78422

Author: aviroop-123

compiler/test-infrastructure/testFixtures/org/jetbrains/kotlin/test/directives/LanguageSettingsDirectives.kt

@@ -142,6 +142,7 @@ object LanguageSettingsDirectives : SimpleDirectivesContainer() {
     val LINK_VIA_SIGNATURES_K1 by directive("Use linkage via signatures instead of descriptors on the K1 frontend")
     val USE_INLINE_SCOPES_NUMBERS by directive("Use inline scopes numbers for inline marker variables")
     val DONT_WARN_ON_ERROR_SUPPRESSION by directive("Don't emit warning when an error is suppressed")
+    val ENABLE_HEADER_MODE by directive("Enable header mode")
 
 
     // --------------------- Utils ---------------------

compiler/tests-common-new/testFixtures/org/jetbrains/kotlin/test/configuration/BaseDiagnosticConfiguration.kt

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.EXPLICIT_
 import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.LANGUAGE
 import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.LANGUAGE_VERSION
 import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.RETURN_VALUE_CHECKER_MODE
+import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives.ENABLE_HEADER_MODE
 import org.jetbrains.kotlin.test.directives.configureFirParser
 import org.jetbrains.kotlin.test.frontend.classic.handlers.FirTestDataConsistencyHandler
 import org.jetbrains.kotlin.test.frontend.fir.*
@@ -293,6 +294,12 @@ fun TestConfigurationBuilder.configureCommonDiagnosticTestPaths(
             LANGUAGE + "+NestedTypeAliases"
         }
     }
+
+    forTestsMatching("compiler/fir/analysis-tests/testData/resolve/headerMode/*") {
+        defaultDirectives {
+            +ENABLE_HEADER_MODE
+        }
+    }
 }
 
 /**

compiler/tests-common-new/testFixtures/org/jetbrains/kotlin/test/frontend/fir/FirFrontendFacade.kt

@@ -45,6 +45,7 @@ import org.jetbrains.kotlin.platform.wasm.WasmTarget
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.test.FirParser
 import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives
+import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives
 import org.jetbrains.kotlin.test.directives.model.DirectivesContainer
 import org.jetbrains.kotlin.test.directives.model.singleValue
 import org.jetbrains.kotlin.test.frontend.fir.handlers.FirDiagnosticCollectorService
@@ -310,7 +311,8 @@ open class FirFrontendFacade(testServices: TestServices) : FrontendFacade<FirOut
             ktFiles.values,
             lightTreeFiles.values,
             parser,
-            testServices.firDiagnosticCollectorService.reporterForLTSyntaxErrors
+            testServices.firDiagnosticCollectorService.reporterForLTSyntaxErrors,
+            headerCompilationMode = (LanguageSettingsDirectives.ENABLE_HEADER_MODE in module.directives)
         )
         val firFiles = firAnalyzerFacade.runResolution()
 

compiler/tests-common-new/testFixtures/org/jetbrains/kotlin/test/services/CompilerConfigurationProvider.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.test.TestInfrastructureInternals
 import org.jetbrains.kotlin.test.directives.CodegenTestDirectives
 import org.jetbrains.kotlin.test.directives.JsEnvironmentConfigurationDirectives
+import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives
 import org.jetbrains.kotlin.test.directives.isApplicableTo
 import org.jetbrains.kotlin.test.model.*
 import org.jetbrains.kotlin.test.utils.MessageCollectorForCompilerTests
@@ -189,6 +190,9 @@ fun createCompilerConfiguration(
             configurator.configureCompileConfigurationWithAdditionalConfigurationKeys(configuration, module)
         }
     }
+    if (LanguageSettingsDirectives.ENABLE_HEADER_MODE in module.directives) {
+        configuration.headerCompilation = true
+    }
 
     return configuration
 }

compiler/tests-compiler-utils/testFixtures/org/jetbrains/kotlin/fir/FirAnalyzerFacade.kt

@@ -25,7 +25,8 @@ class FirAnalyzerFacade(
     val ktFiles: Collection<KtFile> = emptyList(), // may be empty if light tree mode enabled
     val lightTreeFiles: Collection<KtSourceFile> = emptyList(), // may be empty if light tree mode disabled
     val parser: FirParser,
-    val diagnosticReporterForLightTree: DiagnosticReporter? = null
+    val diagnosticReporterForLightTree: DiagnosticReporter? = null,
+    val headerCompilationMode: Boolean = false,
 ) : AbstractFirAnalyzerFacade() {
     private var firFiles: List<FirFile>? = null
     private var _scopeSession: ScopeSession? = null
@@ -38,7 +39,7 @@ class FirAnalyzerFacade(
     private fun buildRawFir() {
         if (firFiles != null) return
         firFiles = when (parser) {
-            FirParser.LightTree -> session.buildFirViaLightTree(lightTreeFiles, diagnosticReporterForLightTree, false, reportFilesAndLines = null)
+            FirParser.LightTree -> session.buildFirViaLightTree(lightTreeFiles, diagnosticReporterForLightTree, headerCompilationMode, reportFilesAndLines = null)
             FirParser.Psi -> session.buildFirFromKtFiles(ktFiles)
         }
     }