Java tutorial
/** * This file is licensed under the terms of the Modified BSD License. */ package abs.backend.erlang; import java.io.*; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import abs.common.CompilerUtils; import abs.backend.common.CodeStream; import abs.backend.erlang.ErlUtil.Mask; import abs.frontend.ast.*; import com.google.common.collect.Iterables; import java.nio.charset.Charset; import org.apache.commons.io.output.WriterOutputStream; /** * Generates the Erlang module for one class * * @author Georg Gri * */ public class ClassGenerator { private final CodeStream ecs; private final ClassDecl classDecl; private final String modName; private final boolean hasFields; public ClassGenerator(ErlApp ea, ClassDecl classDecl) throws IOException { this.classDecl = classDecl; modName = ErlUtil.getName(classDecl); ecs = ea.createSourceFile(modName); hasFields = classDecl.getParams().hasChildren() || classDecl.getFields().hasChildren(); try { generateHeader(); generateExports(); generateConstructor(); generateRecoverHandler(); generateMethods(); generateDataAccess(); } finally { ecs.close(); } } private void generateHeader() { ecs.pf("-module(%s).", modName); ecs.println("-include_lib(\"../include/abs_types.hrl\")."); if (hasFields) { ecs.println("-behaviour(object)."); } } private void generateMethods() { for (MethodImpl m : classDecl.getMethodList()) { ecs.pf(" %%%% %s:%s", m.getFileName(), m.getStartLine()); MethodSig ms = m.getMethodSig(); ecs.pf(" %%%% %s:%s", m.getFileName(), m.getStartLine()); ErlUtil.functionHeader(ecs, "m_" + ms.getName(), generatorClassMatcher(), ms.getParamList()); ecs.println("try"); ecs.incIndent(); Vars vars = Vars.n(ms.getParamList()); m.getBlock().generateErlangCode(ecs, vars); ecs.println(); ecs.decIndent().println("catch"); ecs.incIndent(); ecs.println("_:Error ->"); if (classDecl.hasRecoverBranch()) { ecs.incIndent(); ecs.println("Recovered = try 'recover'(O, Error) catch _:RecoverError -> false end,"); ecs.println("case Recovered of"); ecs.incIndent().println("true -> exit(Error);"); ecs.println("false -> object:die(O, Error), exit(Error)"); ecs.decIndent().println("end"); ecs.decIndent(); } else { ecs.incIndent().println("object:die(O, Error), exit(Error)"); ecs.decIndent(); } ecs.decIndent().println("end."); ecs.decIndent(); } } private void generateConstructor() { ErlUtil.functionHeaderParamsAsList(ecs, "init", generatorClassMatcher(), classDecl.getParamList(), Mask.none); Vars vars = Vars.n(); for (ParamDecl p : classDecl.getParamList()) { ecs.pf("set(O,'%s',%s),", p.getName(), "P_" + p.getName()); } for (FieldDecl p : classDecl.getFields()) { ecs.pf(" %%%% %s:%s", p.getFileName(), p.getStartLine()); if (p.hasInitExp()) { ecs.format("set(O,'%s',", p.getName()); p.getInitExp().generateErlangCode(ecs, vars); ecs.println("),"); } } if (classDecl.getInitBlock() != null) { classDecl.getInitBlock().generateErlangCode(ecs, vars); ecs.println(","); } if (classDecl.isActiveClass()) { ecs.println("cog:process_is_blocked_for_gc(Cog, self()),"); ecs.print("cog:add_sync(Cog,active_object_task,O,"); ecs.print(vars.toStack()); ecs.println("),"); ecs.println("cog:process_is_runnable(Cog,self()),"); ecs.print("task:wait_for_token(Cog,"); ecs.print(vars.toStack()); ecs.println("),"); } ecs.println("O."); ecs.decIndent(); } private void generateRecoverHandler() { if (classDecl.hasRecoverBranch()) { Vars vars = new Vars(); Vars safe = vars.pass(); // Build var scopes and statmemnts for each branch java.util.List<Vars> branches_vars = new java.util.LinkedList<Vars>(); java.util.List<String> branches = new java.util.LinkedList<String>(); for (CaseBranchStmt b : classDecl.getRecoverBranchs()) { Vars v = vars.pass(); StringWriter sw = new StringWriter(); CodeStream buffer = new CodeStream(new WriterOutputStream(sw, Charset.forName("UTF-8")), ""); b.getLeft().generateErlangCode(ecs, buffer, v); buffer.setIndent(ecs.getIndent()); buffer.println("->"); buffer.incIndent(); b.getRight().generateErlangCode(buffer, v); buffer.println(","); buffer.print("true"); buffer.decIndent(); buffer.close(); branches_vars.add(v); branches.add(sw.toString()); vars.updateTemp(v); } ErlUtil.functionHeader(ecs, "recover", ErlUtil.Mask.none, generatorClassMatcher(), "Exception"); ecs.println("Result=case Exception of "); ecs.incIndent(); // Now print statments and mergelines for each branch. java.util.List<String> mergeLines = vars.merge(branches_vars); Iterator<String> ib = branches.iterator(); Iterator<String> im = mergeLines.iterator(); while (ib.hasNext()) { ecs.print(ib.next()); ecs.incIndent(); ecs.print(im.next()); ecs.println(";"); ecs.decIndent(); } ecs.println("_ -> false"); ecs.decIndent(); ecs.print("end"); ecs.println("."); ecs.decIndent(); } } private String generatorClassMatcher() { return String.format("O=#object{class=%s=C,ref=Ref,cog=Cog=#cog{ref=CogRef,dc=DC}}", modName); } private void generateDataAccess() { ErlUtil.functionHeader(ecs, "set", Mask.none, String.format("O=#object{class=%s=C,ref=Ref,cog=Cog}", modName), "Var", "Val"); ecs.println("gen_fsm:send_event(Ref,{O,set,Var,Val})."); ecs.decIndent(); ecs.println(); ErlUtil.functionHeader(ecs, "get", Mask.none, generatorClassMatcher(), "Var"); ecs.println("gen_fsm:sync_send_event(Ref,{O,get,Var})."); ecs.decIndent(); ecs.println(); ecs.print("-record(state,{"); boolean first = true; for (TypedVarOrFieldDecl f : Iterables.concat(classDecl.getParams(), classDecl.getFields())) { if (!first) ecs.print(","); first = false; ecs.format("'%s'=null", f.getName()); } ecs.println("})."); ErlUtil.functionHeader(ecs, "init_internal"); ecs.println("#state{}."); ecs.decIndent(); ecs.println(); for (TypedVarOrFieldDecl f : Iterables.concat(classDecl.getParams(), classDecl.getFields())) { ecs.pf(" %%%% %s:%s", f.getFileName(), f.getStartLine()); ErlUtil.functionHeader(ecs, "get_val_internal", Mask.none, String.format("#state{'%s'=G}", f.getName()), "'" + f.getName() + "'"); ecs.println("G;"); ecs.decIndent(); } ErlUtil.functionHeader(ecs, "get_val_internal", Mask.none, "_", "_"); ecs.println("%% Invalid return value; handled by HTTP API when querying for non-existant field."); ecs.println("%% Will never occur in generated code."); ecs.println("none."); ecs.decIndent(); ecs.println(); if (hasFields) { first = true; for (TypedVarOrFieldDecl f : Iterables.concat(classDecl.getParams(), classDecl.getFields())) { if (!first) { ecs.println(";"); ecs.decIndent(); } first = false; ecs.pf(" %%%% %s:%s", f.getFileName(), f.getStartLine()); ErlUtil.functionHeader(ecs, "set_val_internal", Mask.none, "S", "'" + f.getName() + "'", "V"); ecs.format("S#state{'%s'=V}", f.getName()); } ecs.println("."); ecs.decIndent(); ecs.println(); } else { // Generate failing Dummy ErlUtil.functionHeader(ecs, "set_val_internal", Mask.none, "S", "S", "S"); ecs.println("throw(badarg)."); ecs.decIndent(); } ErlUtil.functionHeader(ecs, "get_all_state", Mask.none, "S"); ecs.println("["); ecs.incIndent(); first = true; for (TypedVarOrFieldDecl f : Iterables.concat(classDecl.getParams(), classDecl.getFields())) { if (!first) ecs.print(", "); first = false; ecs.pf("{ '%s', S#state.%s }", f.getName(), f.getName()); } ecs.decIndent(); ecs.println("]."); } private void generateExports() { ecs.println("-export([get_val_internal/2,set_val_internal/3,init_internal/0,get_all_state/1])."); ecs.println("-compile(export_all)."); ecs.println(); HashSet<MethodSig> callable_sigs = new HashSet<MethodSig>(); HashSet<InterfaceDecl> visited = new HashSet<InterfaceDecl>(); for (InterfaceTypeUse i : classDecl.getImplementedInterfaceUseList()) { visited.add((InterfaceDecl) i.getDecl()); } while (!visited.isEmpty()) { InterfaceDecl id = visited.iterator().next(); visited.remove(id); for (MethodSig ms : id.getBodyList()) { if (ms.isHTTPCallable()) { callable_sigs.add(ms); } } for (InterfaceTypeUse i : id.getExtendedInterfaceUseList()) { visited.add((InterfaceDecl) i.getDecl()); } } ecs.print("exported() -> #{ "); boolean first = true; for (MethodSig ms : callable_sigs) { if (ms.isHTTPCallable()) { if (!first) ecs.print(", "); first = false; ecs.print("<<\"" + ms.getName() + "\">> => { "); ecs.print("'m_" + ms.getName() + "'"); ecs.print(", "); ecs.print("<<\"" + ms.getReturnType().getType().getQualifiedName() + "\">>"); ecs.print(", "); ecs.print("[ "); boolean innerfirst = true; for (ParamDecl p : ms.getParamList()) { if (!innerfirst) ecs.print(", "); innerfirst = false; ecs.print("{ "); ecs.print("<<\"" + p.getName() + "\">>"); ecs.print(", "); ecs.print("<<\"" + p.getAccess().getType().getQualifiedName() + "\">>"); ecs.print(" }"); } ecs.print("] "); ecs.print("}"); } } ecs.println(" }."); ecs.println(); } }