RFR: 8305671: javac rejects semicolons in compilation units with no imports

[Jonathan Gibbons]

On Wed, 5 Apr 2023 18:37:05 GMT, Archie L. Cobbs <duke at openjdk.org> wrote:

> The fix for [JDK-8027682](https://bugs.openjdk.org/browse/JDK-8027682) created a new bug in which a program like this:
> 
> package p;;
> 
> would be rejected.
> 
> This is due to the previous fix swallowing all the semicolons. Instead, in the case of semicolons followed by EOF, it needs to swallow all but the last one.

test/langtools/tools/javac/parser/ExtraPackageSemicolon.java line 42:

> 40: 
> 41:     public static void runTest(String filename, String source) throws Exception {
> 42:         final File sourceFile = new File(filename);

As a matter of style, writing source code to `java.io.File` objects, this feels very old-school, but for a small test program like this, it's not awful.

If this were any bigger, I'd suggest looking at the test `ToolBox` library and/or using `SimpleJavaFileObject` to use more common code idioms and support.

As it is, I'd still suggest using `Files.writeString` to write each source.
https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/nio/file/Files.html#writeString(java.nio.file.Path,java.lang.CharSequence,java.nio.charset.Charset,java.nio.file.OpenOption...)

test/langtools/tools/javac/parser/ExtraPackageSemicolon.java line 45:

> 43:         System.err.println("writing: " + sourceFile);
> 44:         try (PrintStream output = new PrintStream(new FileOutputStream(sourceFile))) {
> 45:             output.println(source);

This would be somewhat overly simplistic (but not wrong) if any source had newlines in it.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/13361#discussion_r1169345681
PR Review Comment: https://git.openjdk.org/jdk/pull/13361#discussion_r1169346313