JVM: do not write trivial SMAPs to classes outside inline funs

where trivial == those that map the file to itself.

compiler/backend/src/org/jetbrains/kotlin/codegen/ClosureCodegen.java

@@ -54,7 +54,6 @@ import static org.jetbrains.kotlin.codegen.AsmUtil.*;
 import static org.jetbrains.kotlin.codegen.CallableReferenceUtilKt.*;
 import static org.jetbrains.kotlin.codegen.JvmCodegenUtil.isConst;
 import static org.jetbrains.kotlin.codegen.binding.CodegenBinding.CLOSURE;
-import static org.jetbrains.kotlin.codegen.inline.InlineCodegenUtilsKt.initDefaultSourceMappingIfNeeded;
 import static org.jetbrains.kotlin.codegen.serialization.JvmSerializationBindings.METHOD_FOR_FUNCTION;
 import static org.jetbrains.kotlin.resolve.jvm.AsmTypes.*;
 import static org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin.NO_ORIGIN;
@@ -170,7 +169,7 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                 superInterfaceAsmTypes
         );
 
-        initDefaultSourceMappingIfNeeded(context, this, state);
+        initDefaultSourceMappingIfNeeded();
 
         v.visitSource(element.getContainingFile().getName(), null);
     }

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -68,7 +68,6 @@ import static org.jetbrains.kotlin.codegen.CodegenUtilKt.isNonGenericToArray;
 import static org.jetbrains.kotlin.codegen.JvmCodegenUtil.*;
 import static org.jetbrains.kotlin.codegen.binding.CodegenBinding.enumEntryNeedSubclass;
 import static org.jetbrains.kotlin.codegen.binding.CodegenBinding.getDelegatedLocalVariableMetadata;
-import static org.jetbrains.kotlin.codegen.inline.InlineCodegenUtilsKt.initDefaultSourceMappingIfNeeded;
 import static org.jetbrains.kotlin.load.java.JvmAbi.*;
 import static org.jetbrains.kotlin.resolve.BindingContext.INDEXED_LVALUE_GET;
 import static org.jetbrains.kotlin.resolve.BindingContext.INDEXED_LVALUE_SET;
@@ -228,7 +227,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
 
         v.visitSource(myClass.getContainingKtFile().getName(), null);
 
-        initDefaultSourceMappingIfNeeded(context, this, state);
+        initDefaultSourceMappingIfNeeded();
 
         writeEnclosingMethod();
 

compiler/backend/src/org/jetbrains/kotlin/codegen/MemberCodegen.java

@@ -88,6 +88,7 @@ public abstract class MemberCodegen<T extends KtPureElement/* TODO: & KtDeclarat
     private NameGenerator inlineNameGenerator;
     private boolean jvmAssertFieldGenerated;
 
+    private boolean alwaysWriteSourceMap;
     private SourceMapper sourceMapper;
 
     public MemberCodegen(
@@ -182,8 +183,8 @@ public abstract class MemberCodegen<T extends KtPureElement/* TODO: & KtDeclarat
 
         writeInnerClasses();
 
-        if (sourceMapper != null) {
-            v.visitSMAP(sourceMapper, !state.getLanguageVersionSettings().supportsFeature(LanguageFeature.CorrectSourceMappingSyntax));
+        if (alwaysWriteSourceMap || (sourceMapper != null && !sourceMapper.isTrivial())) {
+            v.visitSMAP(getOrCreateSourceMapper(), !state.getLanguageVersionSettings().supportsFeature(LanguageFeature.CorrectSourceMappingSyntax));
         }
 
         v.done();
@@ -730,6 +731,19 @@ public abstract class MemberCodegen<T extends KtPureElement/* TODO: & KtDeclarat
         return sourceMapper;
     }
 
+    protected void initDefaultSourceMappingIfNeeded() {
+        if (state.isInlineDisabled()) return;
+
+        CodegenContext parentContext = context.getParentContext();
+        while (parentContext != null) {
+            if (parentContext.isInlineMethodContext()) {
+                alwaysWriteSourceMap = true;
+                return;
+            }
+            parentContext = parentContext.getParentContext();
+        }
+    }
+
     protected void generateConstInstance(@NotNull Type thisAsmType, @NotNull Type fieldAsmType) {
         v.newField(
                 JvmDeclarationOriginKt.OtherOriginFromPure(element), ACC_STATIC | ACC_FINAL | ACC_PUBLIC, JvmAbi.INSTANCE_FIELD,

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/SMAP.kt

@@ -95,6 +95,9 @@ class SourceMapper(val sourceInfo: SourceInfo?) {
         }
     }
 
+    val isTrivial: Boolean
+        get() = maxUsedValue == 0 || maxUsedValue == sourceInfo?.linesInFile
+
     private fun getOrRegisterNewSource(name: String, path: String): FileMapping =
         fileMappings.getOrPut(name to path) { FileMapping(name, path) }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/inlineCodegenUtils.kt

@@ -565,22 +565,6 @@ class InlineOnlySmapSkipper(codegen: BaseExpressionCodegen) {
     }
 }
 
-fun initDefaultSourceMappingIfNeeded(
-    context: CodegenContext<*>, codegen: MemberCodegen<*>, state: GenerationState
-) {
-    if (state.isInlineDisabled) return
-
-    var parentContext: CodegenContext<*>? = context.parentContext
-    while (parentContext != null) {
-        if (parentContext.isInlineMethodContext) {
-            //just init default one to one mapping
-            codegen.orCreateSourceMapper
-            break
-        }
-        parentContext = parentContext.parentContext
-    }
-}
-
 fun MethodNode.preprocessSuspendMarkers(forInline: Boolean, keepFakeContinuation: Boolean = true) {
     if (instructions.first == null) return
     if (!keepFakeContinuation) {