Compiler is found depending on whether provided filenames exist?

[sergutsan]

The code that gets the Java compiler in JDecafCompiler seems to work in misterious ways:
a) If the file to compile exists and is a .jdc, everything works fine.
b) If the file does not exist or is not a .jdc, the compiler is not found.

    private void compile(DecafFile[] files) throws Exception
    {
        boolean hacked = false;
        String hackedJavaHomeBackup=System.getProperty("java.home");
        //get an object to collect diagnostic messages
        DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();

        //get a reference to the compiler
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        if (compiler == null) {
            /* * * Hack to make this work on BBK's labs for now * * * */
            System.out.println("No compiler found... using default...");
             hacked = true;
             System.setProperty("java.home", "C:\\Program Files\\Java\\jdk1.8.0_20");
             compiler = ToolProvider.getSystemJavaCompiler();
             System.out.println("Compiler: " + compiler);
             for (DecafFile file : Arrays.asList(files)) 
                 System.out.println("File: " + file);
             /* * * */
             if (compiler == null) {
                 throw new ConfigurationException("No Java compiler available. Please review your local configuration.");
             }
        }
// ...etc....
` ` ` 

H:\JDecafCompiler\src\JDecafCompiler\source>java -cp .;..\lib\rsyntaxtextarea.jar JDecafCompiler h:\tmp\someFile.jdc
No compiler found... using default...
Compiler: com.sun.tools.javac.api.JavacTool@4617c264
File: someFile.java

H:\JDecafCompiler\src\JDecafCompiler\source>java -cp .;..\lib\rsyntaxtextarea.jar JDecafCompiler h:\tmp\someFile-noexist.jdc
h:\tmp\someFile-noexist.jdc cannot be found
No compiler found... using default...
can't open C:\Program Files\Java\jdk1.8.0_20\lib\tzmappings.
Compiler: null
File: null
Configuration Error: No Java compiler available. Please review your local configuration.

H:\JDecafCompiler\src\JDecafCompiler\source>java -cp .;..\lib\rsyntaxtextarea.jar JDecafCompiler h:\tmp\someFile.java
No compiler found... using default...
can't open C:\Program Files\Java\jdk1.8.0_20\lib\tzmappings.
Compiler: null
File: h:\tmp\someFile.java
Configuration Error: No Java compiler available. Please review your local config
uration.

[sergutsan]

If line 64

                files[i]=file;

is changed to

                try {
                    Precompiler precompiler=new Precompiler();
                    DecafFile file2=precompiler.convert(file);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                files[i]=file;

then the java files work fine.

But why!!??
What is so magic about instantiating and using (discarding the results!) the Precompiler that it affects the way in which the JVM works?

[sergutsan]

See dc87976