A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the fifth batch of tests being updated (there are a significant
number of other tests left to be updated).
Note, the behavior of -ast-print is broken. It prints functions with a
prototype (void) as if they have no prototype () in C. Some tests need
to disable strict prototype checking when recompiling the results of an
-ast-print invocation.
This allows ASTs to be merged when they contain GenericSelectionExpr
nodes (this is _Generic from C11). This is needed, for example, for
CTU analysis of C code that makes use of _Generic, like the Linux
kernel.
The node is already supported in the AST, but it didn't have a matcher
in ASTMatchers. So, this change adds the matcher and adds support to
ASTImporter. Additionally, this change adds support for structural
equivalence of _Generic in the AST.
Reviewed By: martong, aaron.ballman
Differential Revision: https://reviews.llvm.org/D92600