Add check for non-static nested class

Add check for non-static nested class

See error-prone issue 172 (https://code.google.com/p/error-prone/issues/detail?id=172)

[eaftan, 2013-08-21 23:03:46]

Mostly nitpicky style comments.  Looks good otherwise.

Note that we did a major refactoring in the master branch, and this is not going
to integrate cleanly.  I'll take care of that for you, so just don't try to
merge from master into this branch.

Also, can you remove the
core/src/test/resources/com/google/errorprone/bugpatterns/NonStaticInnerClassPositiveCase1$Inner1.class
file from your git tracked files?

When you've made the requested changes, please upload differences from the
reviewed revision and attach it to this issue.  Use this command:
upload.py -i 13117043 --rev <reviewed revision>

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
File
core/src/main/java/com/google/errorprone/bugpatterns/NonStaticInnerClass.java
(right):

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/bugpatterns/NonStaticInnerClass.java:72:
not(classHasModifier(STATIC)),
I would keep the enclosing class names for these constants/enum values. 
"Modifier.STATIC" rather than "STATIC", etc.

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/bugpatterns/NonStaticInnerClass.java:92:
String newmods = mods.toString();
Note that calling toString() on a tree node pretty prints the tree node and does
not always produce the same text that is in the source code.  For example, I bet
this can fail if there are additional spaces between the modifiers.  

The other option would be to use state.getSourceForNode(mods) to get the actual
text, but that doesn't work unless the compiler is invoked with a special
option.

This way is probably fine since the cleanup change went through.  Let's leave it
but add a comment explaining what could go wrong.

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
File core/src/main/java/com/google/errorprone/matchers/HasIdentifier.java
(right):

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/HasIdentifier.java:58:
@Override
There are several indentation problems in this file -- can you autoindent it in
Eclipse?

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/HasIdentifier.java:65: if
(r1==null) return r2;
style nit: we always use braces for if and else blocks

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
File core/src/main/java/com/google/errorprone/matchers/Matchers.java (right):

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/Matchers.java:550: public
static Matcher<ClassTree> classHasModifier(final Modifier modifier) {
Please add javadoc

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/Matchers.java:551: return new
ClassModifier(modifier);
please fix indentation

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/Matchers.java:585: public
static Matcher<ClassTree> nestingKind(final NestingKind kind) {
Please add javadoc

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/Matchers.java:626: public
static MultiMatcher<Tree, IdentifierTree> hasIdentifier(MatchType matchType,
Matcher<IdentifierTree> nodeMatcher) {
Please add javadoc

https://codereview.appspot.com/13117043/diff/1/core/src/main/java/com/google/...
core/src/main/java/com/google/errorprone/matchers/Matchers.java:627: return new
HasIdentifier(matchType, nodeMatcher);
indentation

https://codereview.appspot.com/13117043/diff/1/core/src/test/resources/com/go...
File
core/src/test/resources/com/google/errorprone/bugpatterns/NonStaticInnerClassNegativeCases.java
(right):

https://codereview.appspot.com/13117043/diff/1/core/src/test/resources/com/go...
core/src/test/resources/com/google/errorprone/bugpatterns/NonStaticInnerClassNegativeCases.java:28:
public static class Inner1 { //inner class already static
nit: please add a space in all comments between // and the text

https://codereview.appspot.com/13117043/diff/1/core/src/test/resources/com/go...
File
core/src/test/resources/com/google/errorprone/bugpatterns/NonStaticInnerClassPositiveCase1.java
(right):

https://codereview.appspot.com/13117043/diff/1/core/src/test/resources/com/go...
core/src/test/resources/com/google/errorprone/bugpatterns/NonStaticInnerClassPositiveCase1.java:26:
//Non-static inner class that does not use outer scope
Same as for the negative cases file -- please put a space between // and the
text in a comment.
Don't do this for the //BUG: comments, they use a special format.

[eaftan, 2013-08-28 18:12:16]

Can you please close this issue and the other one by following these
instructions:
https://code.google.com/p/rietveld/wiki/CodeReviewHelp#Closing_the_Issue