Don't reparse headers when collecting macro names

Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Indexer.kt

@@ -913,7 +913,6 @@ internal class NativeIndexImpl(val library: NativeLibrary, val verbose: Boolean
 fun buildNativeIndexImpl(library: NativeLibrary, verbose: Boolean): NativeIndex {
     val result = NativeIndexImpl(library, verbose)
     indexDeclarations(result)
-    findMacros(result)
     return result
 }
 
@@ -955,6 +954,8 @@ private fun indexDeclarations(nativeIndex: NativeIndexImpl) {
                 }
                 CXChildVisitResult.CXChildVisit_Continue
             }
+
+            findMacros(nativeIndex, translationUnit, headers)
         } finally {
             clang_disposeTranslationUnit(translationUnit)
         }

Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/MacroConstants.kt

@@ -23,8 +23,8 @@ import java.io.File
 /**
  * Finds all "macro constants" and registers them as [NativeIndex.constants] in given index.
  */
-internal fun findMacros(nativeIndex: NativeIndexImpl) {
+internal fun findMacros(nativeIndex: NativeIndexImpl, translationUnit: CXTranslationUnit, headers: Set<CXFile?>) {
-    val names = collectMacroNames(nativeIndex)
+    val names = collectMacroNames(nativeIndex, translationUnit, headers)
     // TODO: apply user-defined filters.
     val macros = expandMacros(nativeIndex.library, names, typeConverter = { nativeIndex.convertType(it) })
 
@@ -226,17 +226,8 @@ enum class VisitorState {
     EXPECT_END, INVALID
 }
 
-private fun collectMacroNames(nativeIndex: NativeIndexImpl): List<String> {
+private fun collectMacroNames(nativeIndex: NativeIndexImpl, translationUnit: CXTranslationUnit, headers: Set<CXFile?>): List<String> {
     val result = mutableSetOf<String>()
-    val index = clang_createIndex(excludeDeclarationsFromPCH = 0, displayDiagnostics = 0)!!
-    try {
-        // Include macros into AST:
-        val options = CXTranslationUnit_DetailedPreprocessingRecord
-
-        val translationUnit = nativeIndex.library.parse(index, options)
-        try {
-            translationUnit.ensureNoCompileErrors()
-            val headers = getFilteredHeaders(nativeIndex, index, translationUnit)
 
     visitChildren(translationUnit) { cursor, _ ->
         val file = memScoped {
@@ -257,13 +248,6 @@ private fun collectMacroNames(nativeIndex: NativeIndexImpl): List<String> {
         CXChildVisitResult.CXChildVisit_Continue
     }
 
-        } finally {
-            clang_disposeTranslationUnit(translationUnit)
-        }
-    } finally {
-        clang_disposeIndex(index)
-    }
-
     return result.toList()
 }