"source" comment in generated code can produce files that don't compile

[orischwartz]

This line

closure-templates/java/src/com/google/template/soy/parseinfo/passes/GenerateParseInfoVisitor.java

Line 349 in 5aef0db

ilb.appendLine("// source: ", node.getFilePath());

can lead to files that don't compile on windows because they'll have an illegal unicode escape.

For example, if you have a file called utils.soy and run SoyParseInfoGenerator on it, it generates code like this:

// This file was automatically generated by the Soy compiler. 
// Please don't edit this file by hand.
// source: C:\XXXXX\src\main\resources\soy\utils.soy
package xxx;

You can put a unicode escape anywhere in a java file, including comments. So trying to compile the above leads to:

UtilsSoyInfo.java:3: error: illegal unicode escape
// source: C:\XXXXX\src\main\resources\soy\utils.soy
                                            ^

1 error

Introduced via b0b39f9

This would affect any soy file with a path segment that starts with a u on Windows.