Support -Xg0 compiler flag (#3154)

Enables generation of partial debug information
(e.g. useful for crash reports symbolication).

Supposed to avoid affecting '-opt' optimization quality.

backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2Native.kt

@@ -150,6 +150,7 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
                 put(LIST_TARGETS, arguments.listTargets)
                 put(OPTIMIZATION, arguments.optimization)
                 put(DEBUG, arguments.debug)
+                put(LIGHT_DEBUG, arguments.lightDebug)
                 put(STATIC_FRAMEWORK, selectFrameworkType(configuration, arguments, outputKind))
 
                 put(PRINT_IR, arguments.printIr)

backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2NativeCompilerArguments.kt

@@ -133,6 +133,9 @@ class K2NativeCompilerArguments : CommonCompilerArguments() {
     )
     var frameworkImportHeaders: Array<String>? = null
 
+    @Argument(value = "-Xg0", description = "Add light debug information")
+    var lightDebug: Boolean = false
+
     @Argument(value = "-Xprint-bitcode", deprecatedName = "--print_bitcode", description = "Print llvm bitcode")
     var printBitCode: Boolean = false
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Context.kt

@@ -428,6 +428,8 @@ internal class Context(config: KonanConfig) : KonanBackendContext(config) {
     fun shouldProfilePhases() = config.phaseConfig.needProfiling
 
     fun shouldContainDebugInfo() = config.debug
+    fun shouldContainLocationDebugInfo() = shouldContainDebugInfo() || config.lightDebug
+    fun shouldContainAnyDebugInfo() = shouldContainDebugInfo() || shouldContainLocationDebugInfo()
 
     fun shouldOptimize() = config.configuration.getBoolean(KonanConfigKeys.OPTIMIZATION)
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfig.kt

@@ -44,7 +44,9 @@ class KonanConfig(val project: Project, val configuration: CompilerConfiguration
 
     val infoArgsOnly = configuration.kotlinSourceRoots.isEmpty() && !linkOnly
 
+    // TODO: debug info generation mode and debug/release variant selection probably requires some refactoring.
     val debug: Boolean get() = configuration.getBoolean(KonanConfigKeys.DEBUG)
+    val lightDebug: Boolean get() = configuration.getBoolean(KonanConfigKeys.LIGHT_DEBUG)
 
     val memoryModel: MemoryModel get() = configuration.get(KonanConfigKeys.MEMORY_MODEL)!!
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfigurationKeys.kt

@@ -44,6 +44,8 @@ class KonanConfigKeys {
                 = CompilerConfigurationKey.create("library file paths")
         val LIBRARY_VERSION: CompilerConfigurationKey<String?>
                 = CompilerConfigurationKey.create("library version")
+        val LIGHT_DEBUG: CompilerConfigurationKey<Boolean>
+                = CompilerConfigurationKey.create("add light debug information")
         val LINKER_ARGS: CompilerConfigurationKey<List<String>>
                 = CompilerConfigurationKey.create("additional linker arguments")
         val LIST_PHASES: CompilerConfigurationKey<Boolean>

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Linker.kt

@@ -28,7 +28,7 @@ internal class Linker(val context: Context) {
     private val linker = platform.linker
     private val target = context.config.target
     private val optimize = context.shouldOptimize()
-    private val debug = context.config.debug
+    private val debug = context.config.debug || context.config.lightDebug
 
     // Ideally we'd want to have
     //      #pragma weak main = Konan_main

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BitcodePhases.kt

@@ -210,7 +210,7 @@ internal val finalizeDebugInfoPhase = makeKonanModuleOpPhase(
         name = "FinalizeDebugInfo",
         description = "Finalize debug info",
         op = { context, _ ->
-            if (context.shouldContainDebugInfo()) {
+            if (context.shouldContainAnyDebugInfo()) {
                 DIFinalize(context.debugInfo.builder)
             }
         }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt

@@ -673,7 +673,7 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
     }
 
     internal fun debugLocation(startLocationInfo: LocationInfo, endLocation: LocationInfo?): DILocationRef? {
-        if (!context.shouldContainDebugInfo()) return null
+        if (!context.shouldContainLocationDebugInfo()) return null
         update(currentBlock, startLocationInfo, endLocation)
         val debugLocation = codegen.generateLocationInfo(startLocationInfo)
         currentPositionHolder.setBuilderDebugLocation(debugLocation)
@@ -880,7 +880,7 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
     }
 
     fun resetDebugLocation() {
-        if (!context.shouldContainDebugInfo()) return
+        if (!context.shouldContainLocationDebugInfo()) return
         currentPositionHolder.resetBuilderDebugLocation()
     }
 
@@ -1057,12 +1057,12 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
         }
 
         fun resetBuilderDebugLocation() {
-            if (!context.shouldContainDebugInfo()) return
+            if (!context.shouldContainLocationDebugInfo()) return
             LLVMBuilderResetDebugLocation(builder)
         }
 
         fun setBuilderDebugLocation(debugLocation: DILocationRef?) {
-            if (!context.shouldContainDebugInfo()) return
+            if (!context.shouldContainLocationDebugInfo()) return
             LLVMBuilderSetDebugLocation(builder, debugLocation)
         }
     }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/DebugUtils.kt

@@ -116,7 +116,7 @@ internal fun String?.toFileAndFolder():FileAndFolder {
 }
 
 internal fun generateDebugInfoHeader(context: Context) {
-    if (context.shouldContainDebugInfo()) {
+    if (context.shouldContainAnyDebugInfo()) {
         val path = context.config.outputFile
             .toFileAndFolder()
         @Suppress("UNCHECKED_CAST")

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -608,7 +608,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
 
 
         private val scope by lazy {
-            if (!context.shouldContainDebugInfo())
+            if (!context.shouldContainLocationDebugInfo())
                 return@lazy null
             declaration?.scope() ?: llvmFunction!!.scope(0, subroutineType(context, codegen.llvmTargetData, listOf(context.irBuiltIns.intType)))
         }
@@ -672,7 +672,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
     }
 
     private fun IrFunction.location(start: Boolean) =
-            if (context.shouldContainDebugInfo() && startOffset != UNDEFINED_OFFSET) LocationInfo(
+            if (context.shouldContainLocationDebugInfo() && startOffset != UNDEFINED_OFFSET) LocationInfo(
                 scope = scope()!!,
                 line = if (start) startLine() else endLine(),
                 column = if (start) startColumn() else endColumn())
@@ -1600,7 +1600,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
          * Note: DILexicalBlocks aren't nested, they should be scoped with the parent function.
          */
         private val scope by lazy {
-            if (!context.shouldContainDebugInfo() || returnableBlock.startOffset == UNDEFINED_OFFSET)
+            if (!context.shouldContainLocationDebugInfo() || returnableBlock.startOffset == UNDEFINED_OFFSET)
                 return@lazy null
             val lexicalBlockFile = DICreateLexicalBlockFile(context.debugInfo.builder, functionScope()!!.scope(), super.file.file())
             DICreateLexicalBlock(context.debugInfo.builder, lexicalBlockFile, super.file.file(), returnableBlock.startLine(), returnableBlock.startColumn())!!
@@ -1619,7 +1619,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
 
         @Suppress("UNCHECKED_CAST")
         private val scope by lazy {
-            if (!context.shouldContainDebugInfo())
+            if (!context.shouldContainLocationDebugInfo())
                 return@lazy null
             file.file() as DIScopeOpaqueRef?
         }
@@ -1734,16 +1734,16 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
 
     //-------------------------------------------------------------------------//
     private fun updateBuilderDebugLocation(element: IrElement) {
-        if (!context.shouldContainDebugInfo() || currentCodeContext.functionScope() == null || element.startLocation == null) return
+        if (!context.shouldContainLocationDebugInfo() || currentCodeContext.functionScope() == null || element.startLocation == null) return
         functionGenerationContext.debugLocation(element.startLocation!!, element.endLocation!!)
     }
 
     private val IrElement.startLocation: LocationInfo?
-        get() = if (!context.shouldContainDebugInfo() || startOffset == UNDEFINED_OFFSET) null
+        get() = if (!context.shouldContainLocationDebugInfo() || startOffset == UNDEFINED_OFFSET) null
             else currentCodeContext.location(startLine(), startColumn())
 
     private val IrElement.endLocation: LocationInfo?
-        get() = if (!context.shouldContainDebugInfo() || startOffset == UNDEFINED_OFFSET) null
+        get() = if (!context.shouldContainLocationDebugInfo() || startOffset == UNDEFINED_OFFSET) null
             else currentCodeContext.location(endLine(), endColumn())
 
     //-------------------------------------------------------------------------//
@@ -1807,7 +1807,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
 
     @Suppress("UNCHECKED_CAST")
     private fun IrFunction.scope(startLine:Int): DIScopeOpaqueRef? {
-        if (codegen.isExternal(this) || !context.shouldContainDebugInfo())
+        if (codegen.isExternal(this) || !context.shouldContainLocationDebugInfo())
             return null
         val functionLlvmValue = codegen.llvmFunctionOrNull(this)
         return if (functionLlvmValue != null) {

shared/src/main/kotlin/org/jetbrains/kotlin/konan/target/Linker.kt

@@ -132,6 +132,7 @@ open class MacOSBasedLinker(targetProperties: AppleConfigurables)
 
     private val libtool = "$absoluteTargetToolchain/usr/bin/libtool"
     private val linker = "$absoluteTargetToolchain/usr/bin/ld"
+    private val strip = "$absoluteTargetToolchain/usr/bin/strip"
     private val dsymutil = "$absoluteLlvmHome/bin/llvm-dsymutil"
 
     private fun provideCompilerRtLibrary(libraryName: String): String? {
@@ -177,7 +178,10 @@ open class MacOSBasedLinker(targetProperties: AppleConfigurables)
                 +libraries
             })
         val dynamic = kind == LinkerOutputKind.DYNAMIC_LIBRARY
-        return listOf(Command(linker).apply {
+
+        val result = mutableListOf<Command>()
+
+        result += Command(linker).apply {
             +"-demangle"
             +listOf("-dynamic", "-arch", arch)
             +osVersionMinFlags
@@ -192,7 +196,17 @@ open class MacOSBasedLinker(targetProperties: AppleConfigurables)
             +libraries
             +linkerArgs
             +rpath(dynamic)
-        }) + if (debug) listOf(dsymUtilCommand(executable, outputDsymBundle)) else emptyList()
+        }
+
+        // TODO: revise debug information handling.
+        if (debug) {
+            result += dsymUtilCommand(executable, outputDsymBundle)
+            if (optimize) {
+                result += Command(strip, "-S", executable)
+            }
+        }
+
+        return result
     }
 
     private fun rpath(dynamic: Boolean): List<String> = listOfNotNull(