callgraph improved unused node checking

compiler/src/prog8/optimizer/CallGraph.kt

@@ -21,18 +21,17 @@ class CallGraph(private val program: Program) : IAstVisitor {
     val calls = mutableMapOf<Subroutine, Set<Subroutine>>().withDefault { setOf() }
     val calledBy = mutableMapOf<Subroutine, Set<Node>>().withDefault { setOf() }
     private val allIdentifiersAndTargets = mutableMapOf<Pair<IdentifierReference, Position>, Statement>()
+    private val allAssemblyNodes = mutableListOf<InlineAssembly>()
 
     init {
         visit(program)
     }
 
     private val usedSubroutines: Set<Subroutine> by lazy {
-        // TODO also check inline assembly if it uses the subroutine
         calledBy.keys
     }
 
     private val usedBlocks: Set<Block> by lazy {
-        // TODO also check inline assembly if it uses the block
         val blocksFromSubroutines = usedSubroutines.map { it.definingBlock() }
         val blocksFromLibraries = program.allBlocks().filter { it.isInLibrary }
         val used = mutableSetOf<Block>()
@@ -110,6 +109,10 @@ class CallGraph(private val program: Program) : IAstVisitor {
         allIdentifiersAndTargets[Pair(identifier, identifier.position)] = identifier.targetStatement(program)!!
     }
 
+    override fun visit(inlineAssembly: InlineAssembly) {
+        allAssemblyNodes.add(inlineAssembly)
+    }
+
     fun checkRecursiveCalls(errors: IErrorReporter) {
         val cycles = recursionCycles()
         if(cycles.any()) {
@@ -163,9 +166,13 @@ class CallGraph(private val program: Program) : IAstVisitor {
 
     fun unused(module: Module) = module !in usedModules
 
-    fun unused(sub: Subroutine) = sub !in usedSubroutines
+    fun unused(sub: Subroutine): Boolean {
+        return sub !in usedSubroutines && !nameInAssemblyCode(sub.name)
+    }
 
-    fun unused(block: Block) = block !in usedBlocks
+    fun unused(block: Block): Boolean {
+        return block !in usedBlocks && !nameInAssemblyCode(block.name)
+    }
 
     fun unused(decl: VarDecl): Boolean {
         if(decl.type!=VarDeclType.VAR || decl.datatype==DataType.STRUCT || decl.autogeneratedDontRemove || decl.parent is StructDecl)
@@ -174,19 +181,11 @@ class CallGraph(private val program: Program) : IAstVisitor {
         if(decl.definingBlock() !in usedBlocks)
             return false
 
-        // TODO also check inline asm for references to the var
         val allReferencedVardecls = allIdentifiersAndTargets.filter { it.value is VarDecl }.map { it.value }.toSet()
-
+        return decl !in allReferencedVardecls && !nameInAssemblyCode(decl.name)
-        return decl !in allReferencedVardecls
     }
 
-    fun unused(struct: StructDecl): Boolean {
+    private fun nameInAssemblyCode(name: String) = allAssemblyNodes.any { it.assembly.contains(name) }
-        if(struct.definingBlock() !in usedBlocks)
-            return false
-
-        // TODO implement unused check for struct decls, also check inline asm
-        return false
-    }
 
     inline fun unused(label: Label) = false   // just always output labels
 
@@ -196,7 +195,6 @@ class CallGraph(private val program: Program) : IAstVisitor {
             is Block -> unused(stmt)
             is VarDecl -> unused(stmt)
             is Label -> false   // just always output labels
-            is StructDecl -> unused(stmt)
             else -> false
         }
     }

compilerAst/src/prog8/ast/statements/AstStatements.kt

@@ -948,7 +948,7 @@ class WhenChoice(var values: MutableList<Expression>?,           // if null,  th
 
 class StructDecl(override val name: String,
                  override var statements: MutableList<Statement>,      // actually, only vardecls here
-                 override val position: Position): Statement(), INameScope, ISymbolStatement {
+                 override val position: Position): Statement(), INameScope {
 
     override lateinit var parent: Node
 

docs/source/todo.rst

@@ -2,8 +2,6 @@
 TODO
 ====
 
-- implement new 'unused' in CallGraph for more node types
-
 - allow inlining of subroutines with params
 - optimize several inner loops in gfx2
 - hoist all variable declarations up to the subroutine scope *before* even the constant folding takes place (to avoid undefined symbol errors when referring to a variable from another nested scope in the subroutine)