Merge branch 'v7.1'

compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt

@@ -120,13 +120,13 @@ internal class BeforeAsmGenerationAstChanger(val program: Program, val errors: I
         // and if an assembly block doesn't contain a rts/rti, and some other situations.
         val mods = mutableListOf<IAstModification>()
         val returnStmt = Return(null, subroutine.position)
-        if (subroutine.asmAddress == null
-                && !subroutine.inline
-                && subroutine.statements.isNotEmpty()
-                && subroutine.amountOfRtsInAsm() == 0
+        if (subroutine.asmAddress == null && !subroutine.inline) {
+            if(subroutine.statements.isEmpty() ||
+                (subroutine.amountOfRtsInAsm() == 0
                 && subroutine.statements.lastOrNull { it !is VarDecl } !is Return
-                && subroutine.statements.last() !is Subroutine) {
-            mods += IAstModification.InsertLast(returnStmt, subroutine)
+                && subroutine.statements.last() !is Subroutine)) {
+                    mods += IAstModification.InsertLast(returnStmt, subroutine)
+            }
         }
 
         // precede a subroutine with a return to avoid falling through into the subroutine from code above it

compiler/src/prog8/optimizer/UnusedCodeRemover.kt

@@ -81,20 +81,20 @@ internal class UnusedCodeRemover(private val program: Program,
         val forceOutput = "force_output" in subroutine.definingBlock.options()
         if (subroutine !== program.entrypoint && !forceOutput && !subroutine.inline && !subroutine.isAsmSubroutine) {
             if(callgraph.unused(subroutine)) {
+                if(subroutine.containsNoCodeNorVars) {
+                    if(!subroutine.definingModule.isLibrary)
+                        errors.warn("removing empty subroutine '${subroutine.name}'", subroutine.position)
+                    val removals = mutableListOf(IAstModification.Remove(subroutine, subroutine.definingScope))
+                    callgraph.calledBy[subroutine]?.let {
+                        for(node in it)
+                            removals.add(IAstModification.Remove(node, node.definingScope))
+                    }
+                    return removals
+                }
                 if(!subroutine.definingModule.isLibrary)
                     errors.warn("removing unused subroutine '${subroutine.name}'", subroutine.position)
                 return listOf(IAstModification.Remove(subroutine, subroutine.definingScope))
             }
-            if(subroutine.containsNoCodeNorVars) {
-                if(!subroutine.definingModule.isLibrary)
-                    errors.warn("removing empty subroutine '${subroutine.name}'", subroutine.position)
-                val removals = mutableListOf(IAstModification.Remove(subroutine, subroutine.definingScope))
-                callgraph.calledBy[subroutine]?.let {
-                    for(node in it)
-                        removals.add(IAstModification.Remove(node, node.definingScope))
-                }
-                return removals
-            }
         }
 
         val removeDoubleAssignments = deduplicateAssignments(subroutine.statements)

compiler/test/TestCallgraph.kt

@@ -0,0 +1,91 @@
+package prog8tests
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.TestInstance
+import prog8.ast.statements.Block
+import prog8.ast.statements.Subroutine
+import prog8.compiler.target.C64Target
+import prog8.optimizer.CallGraph
+import prog8tests.helpers.assertSuccess
+import prog8tests.helpers.compileText
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class TestCallgraph {
+    @Test
+    fun testGraphForEmptySubs() {
+        val sourcecode = """
+            %import string
+            main {
+                sub start() {
+                }
+                sub empty() {
+                }
+            }
+        """
+        val result = compileText(C64Target, false, sourcecode).assertSuccess()
+        val graph = CallGraph(result.programAst)
+
+        assertEquals(1, graph.imports.size)
+        assertEquals(1, graph.importedBy.size)
+        val toplevelModule = result.programAst.toplevelModule
+        val importedModule = graph.imports.getValue(toplevelModule).single()
+        assertEquals("string", importedModule.name)
+        val importedBy = graph.importedBy.getValue(importedModule).single()
+        assertTrue(importedBy.name.startsWith("on_the_fly_test"))
+
+        assertFalse(graph.unused(toplevelModule))
+        assertFalse(graph.unused(importedModule))
+
+        val mainBlock = toplevelModule.statements.filterIsInstance<Block>().single()
+        for(stmt in mainBlock.statements) {
+            val sub = stmt as Subroutine
+            assertFalse(sub in graph.calls)
+            assertFalse(sub in graph.calledBy)
+
+            if(sub === result.programAst.entrypoint)
+                assertFalse(graph.unused(sub), "start() should always be marked as used to avoid having it removed")
+            else
+                assertTrue(graph.unused(sub))
+        }
+    }
+
+    @Test
+    fun testGraphForEmptyButReferencedSub() {
+        val sourcecode = """
+            %import string
+            main {
+                sub start() {
+                    uword xx = &empty
+                    xx++
+                }
+                sub empty() {
+                }
+            }
+        """
+        val result = compileText(C64Target, false, sourcecode).assertSuccess()
+        val graph = CallGraph(result.programAst)
+
+        assertEquals(1, graph.imports.size)
+        assertEquals(1, graph.importedBy.size)
+        val toplevelModule = result.programAst.toplevelModule
+        val importedModule = graph.imports.getValue(toplevelModule).single()
+        assertEquals("string", importedModule.name)
+        val importedBy = graph.importedBy.getValue(importedModule).single()
+        assertTrue(importedBy.name.startsWith("on_the_fly_test"))
+
+        assertFalse(graph.unused(toplevelModule))
+        assertFalse(graph.unused(importedModule))
+
+        val mainBlock = toplevelModule.statements.filterIsInstance<Block>().single()
+        val startSub = mainBlock.statements.filterIsInstance<Subroutine>().single{it.name=="start"}
+        val emptySub = mainBlock.statements.filterIsInstance<Subroutine>().single{it.name=="empty"}
+
+        assertTrue(startSub in graph.calls, "start 'calls' (references) empty")
+        assertFalse(emptySub in graph.calls, "empty doesn't call anything")
+        assertTrue(emptySub in graph.calledBy, "empty gets 'called'")
+        assertFalse(startSub in graph.calledBy, "start doesn't get called (except as entrypoint ofc.)")
+    }
+}

compiler/test/TestOptimization.kt

@@ -0,0 +1,59 @@
+package prog8tests
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.TestInstance
+import prog8.ast.statements.Block
+import prog8.ast.statements.Subroutine
+import prog8.compiler.target.C64Target
+import prog8tests.helpers.assertSuccess
+import prog8tests.helpers.compileText
+import kotlin.test.assertEquals
+import kotlin.test.assertSame
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class TestOptimization {
+    @Test
+    fun testRemoveEmptySubroutineExceptStart() {
+        val sourcecode = """
+            main {
+                sub start() {
+                }
+                sub empty() {
+                    ; going to be removed
+                }
+            }
+        """
+        val result = compileText(C64Target, true, sourcecode).assertSuccess()
+        val toplevelModule = result.programAst.toplevelModule
+        val mainBlock = toplevelModule.statements.single() as Block
+        assertEquals(1, mainBlock.statements.size)
+        val startSub = mainBlock.statements[0] as Subroutine
+        assertSame(result.programAst.entrypoint, startSub)
+        assertEquals("start", startSub.name)
+        assertEquals(0, startSub.statements.size)
+    }
+
+    @Test
+    fun testDontRemoveEmptySubroutineIfItsReferenced() {
+        val sourcecode = """
+            main {
+                sub start() {
+                    uword xx = &empty
+                    xx++
+                }
+                sub empty() {
+                    ; should not be removed
+                }
+            }
+        """
+        val result = compileText(C64Target, true, sourcecode).assertSuccess()
+        val toplevelModule = result.programAst.toplevelModule
+        val mainBlock = toplevelModule.statements.single() as Block
+        val startSub = mainBlock.statements[0] as Subroutine
+        val emptySub = mainBlock.statements[1] as Subroutine
+        assertSame(result.programAst.entrypoint, startSub)
+        assertEquals("start", startSub.name)
+        assertEquals("empty", emptySub.name)
+        assertEquals(0, emptySub.statements.size)
+    }
+}

examples/test.p8

@@ -1,18 +1,10 @@
-%import textio
-
 main {
     sub start() {
-        ubyte xx
+        uword address = &irq
+        ; cx16.set_irq(&irq, false)
+        address++
+    }
 
-        when xx {
-            2 -> {
-            }
-            3 -> {
-            }
-            50 -> {
-            }
-            else -> {
-            }
-        }
+    sub irq() {
     }
 }