Merge pull request yui#187 from tml/preserveHints

Provide an option to preserve unknown hints

Author: tml

src/com/yahoo/platform/yui/compressor/JavaScriptCompressor.java

@@ -520,6 +520,7 @@ private static void optimizeObjLitMemberDecl(ArrayList tokens) {
 
     private boolean munge;
     private boolean verbose;
+    private boolean preserveUnknownHints;
 
     private static final int BUILDING_SYMBOL_TREE = 1;
     private static final int CHECKING_SYMBOL_TREE = 2;
@@ -541,14 +542,16 @@ public JavaScriptCompressor(Reader in, ErrorReporter reporter)
     public void compress(Writer out, int linebreak, boolean munge, boolean verbose,
             boolean preserveAllSemiColons, boolean disableOptimizations) 
             throws IOException {
-        compress(out, null, linebreak, munge, verbose, preserveAllSemiColons, disableOptimizations);
+        compress(out, null, linebreak, munge, verbose, preserveAllSemiColons, 
+            disableOptimizations, false);
     }
     public void compress(Writer out, Writer mungemap, int linebreak, boolean munge, boolean verbose,
-            boolean preserveAllSemiColons, boolean disableOptimizations)
+            boolean preserveAllSemiColons, boolean disableOptimizations, boolean preserveUnknownHints)
             throws IOException {
 
         this.munge = munge;
         this.verbose = verbose;
+        this.preserveUnknownHints = preserveUnknownHints;
 
         processStringLiterals(this.tokens, !disableOptimizations);
 
@@ -730,9 +733,9 @@ private void parseFunctionDeclaration() {
                 String hint = st1.nextToken();
                 int idx = hint.indexOf(':');
                 if (idx <= 0 || idx >= hint.length() - 1) {
-                    if (mode == BUILDING_SYMBOL_TREE) {
+                    if (mode == BUILDING_SYMBOL_TREE && (! preserveUnknownHints)) {
                         // No need to report the error twice, hence the test...
-                        warn("Invalid hint syntax: " + hint, true);
+                        warn("Not a YUICompressor hint: " + hint, true);
                     }
                     break;
                 }
@@ -1239,9 +1242,11 @@ private StringBuffer printSymbolTree(int linebreakpos, boolean preserveAllSemiCo
                     token = getToken(0);
                     if (token.getType() == Token.STRING &&
                             getToken(1).getType() == Token.SEMI) {
-                        // This is a hint. Skip it!
-                        consumeToken();
-                        consumeToken();
+                        if (! preserveUnknownHints) {
+                            // This is an unknown hint. Skip it!
+                            consumeToken();
+                            consumeToken();
+                        }
                     }
                     break;
 

src/com/yahoo/platform/yui/compressor/YUICompressor.java

@@ -31,6 +31,7 @@ public static void main(String args[]) {
         CmdLineParser.Option charsetOpt = parser.addStringOption("charset");
         CmdLineParser.Option outputFilenameOpt = parser.addStringOption('o', "output");
         CmdLineParser.Option mungemapFilenameOpt = parser.addStringOption('m', "mungemap");
+        CmdLineParser.Option preserveUnknownHintsOpt = parser.addBooleanOption('p', "preservehints");
 
         Reader in = null;
         Writer out = null;
@@ -90,6 +91,7 @@ public static void main(String args[]) {
             boolean munge = parser.getOptionValue(nomungeOpt) == null;
             boolean preserveAllSemiColons = parser.getOptionValue(preserveSemiOpt) != null;
             boolean disableOptimizations = parser.getOptionValue(disableOptimizationsOpt) != null;
+            boolean preserveUnknownHints = parser.getOptionValue(preserveUnknownHintsOpt) != null;
 
             String[] fileArgs = parser.getRemainingArgs();
             java.util.List files = java.util.Arrays.asList(fileArgs);
@@ -206,7 +208,7 @@ public EvaluatorException runtimeError(String message, String sourceName,
                             }
 
                             compressor.compress(out, mungemap, linebreakpos, munge, verbose,
-                                    preserveAllSemiColons, disableOptimizations);
+                                    preserveAllSemiColons, disableOptimizations, preserveUnknownHints);
 
                         } catch (EvaluatorException e) {
 
@@ -288,6 +290,7 @@ private static void usage() {
                         + "  --charset <charset>       Read the input file using <charset>\n"
                         + "  --line-break <column>     Insert a line break after the specified column number\n"
                         + "  -v, --verbose             Display informational messages and warnings\n"
+                        + "  -p, --preservehints       Don't elide unrecognized compiler hints (e.g. \"use strict\", \"use asm\")\n"
                         + "  -m <file>                 Place a mapping of munged identifiers to originals in this file\n\n"
                         + "  -o <file>                 Place the output into <file>. Defaults to stdout.\n"
                         + "                            Multiple files can be processed using the following syntax:\n"

tests/issue71.js.FAIL

@@ -0,0 +1,4 @@
+function foo() {
+    "use strict";
+    alert('hello');
+}

tests/issue71.js.min

@@ -0,0 +1 @@
+function foo(){"use strict";alert('hello');}