PatternCompiler should have public modifier

At the moment, we are trying to modularize guava on the fly before linking with jlink.

In order to use modular JAR in the future PatternCompiler must have public modifier.

Otherwise: ServiceLoader throws exception - java.util.ServiceConfigurationError: com.google.common.base.PatternCompiler: module com.google.common does not declare uses

Also, we cannot define “uses” in module-info.java for com.google.common.base.PatternCompiler:

~/com.google.common/module-info.java:27: error: PatternCompiler is not public in com.google.common.base; cannot be accessed from outside package
uses com.google.common.base.PatternCompiler;

Solution: define com.google.common.base.PatternCompiler as public, any way, split packages are not allowed in modular environment

[cpovirk]

And thank you for uncovering and reporting this! As you can tell, our Java 9 testing and fixes addressed only some of the issues that the module system can cause.

[jreznot]

You could move this line https://github.com/google/guava/blob/master/guava/src/com/google/common/base/Platform.java#L80 into try block. Anyway, ServiceLoader will throw exception for package-private class in modularized environments, thus custom PatternCompiler will not work.