fix corner cases in dead_code & if_return (#5525)

fixes #5521 fixes #5522 fixes #5523 fixes #5524

Author: alexlamsl

lib/compress.js

@@ -1953,7 +1953,7 @@ Compressor.prototype.compress = function(node) {
  function last_of(compressor, predicate) {
  var block = compressor.self(), level = 0;
  do {
- if (block instanceof AST_Catch || block instanceof AST_Finally) {
+ if (block instanceof AST_Catch) {
  block = compressor.parent(level++);
  } else if (block instanceof AST_LabeledStatement) {
  block = block.body;
@@ -1968,7 +1968,6 @@ Compressor.prototype.compress = function(node) {
  } while (stat
  && (block instanceof AST_BlockStatement
  || block instanceof AST_Catch
- || block instanceof AST_Finally
  || block instanceof AST_Scope
  || block instanceof AST_Try)
  && is_last_statement(block.body, stat));
@@ -3690,7 +3689,7 @@ Compressor.prototype.compress = function(node) {
  function eliminate_dead_code(statements, compressor) {
  var has_quit;
  var self = compressor.self();
- if (self instanceof AST_Catch || self instanceof AST_Finally) {
+ if (self instanceof AST_Catch) {
  self = compressor.parent();
  } else if (self instanceof AST_LabeledStatement) {
  self = self.body;

test/compress/if_return.js

@@ -963,3 +963,57 @@ issue_4374: {
  }
  expect_stdout: "0"
 }
+
+issue_5521: {
+ options = {
+ if_return: true,
+ }
+ input: {
+ console.log(function() {
+ if (console)
+ try {
+ return "FAIL";
+ } finally {
+ return;
+ }
+ }());
+ }
+ expect: {
+ console.log(function() {
+ if (console)
+ try {
+ return "FAIL";
+ } finally {
+ return;
+ }
+ }());
+ }
+ expect_stdout: "undefined"
+}
+
+issue_5523: {
+ options = {
+ if_return: true,
+ }
+ input: {
+ console.log(function() {
+ if (console)
+ try {
+ FAIL;
+ } finally {
+ return;
+ }
+ }());
+ }
+ expect: {
+ console.log(function() {
+ if (console)
+ try {
+ FAIL;
+ } finally {
+ return;
+ }
+ }());
+ }
+ expect_stdout: "undefined"
+}

test/compress/labels.js

@@ -230,7 +230,6 @@ labels_12: {
  conditionals: true,
  dead_code: true,
  if_return: true,
- unused: true,
  }
  input: {
  L: try {
@@ -246,13 +245,14 @@ labels_12: {
  }
  }
  expect: {
- try {
+ L: try {
  if (!console.log("foo"))
  throw "bar";
  } catch (e) {
  console.log(e);
  } finally {
- console.log("baz")
+ if (console.log("baz"))
+ break L;
  }
  }
  expect_stdout: [
@@ -381,3 +381,53 @@ issue_4466_2_toplevel_v8: {
  }
  expect_stdout: "PASS"
 }
+
+issue_5522: {
+ options = {
+ dead_code: true,
+ }
+ input: {
+ console.log(function() {
+ L: try {
+ return "FAIL";
+ } finally {
+ break L;
+ }
+ return "PASS";
+ }());
+ }
+ expect: {
+ console.log(function() {
+ L: try {
+ return "FAIL";
+ } finally {
+ break L;
+ }
+ return "PASS";
+ }());
+ }
+ expect_stdout: "PASS"
+}
+
+issue_5524: {
+ options = {
+ dead_code: true,
+ }
+ input: {
+ L: try {
+ FAIL;
+ } finally {
+ break L;
+ }
+ console.log("PASS");
+ }
+ expect: {
+ L: try {
+ FAIL;
+ } finally {
+ break L;
+ }
+ console.log("PASS");
+ }
+ expect_stdout: "PASS"
+}