https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120249
Bug ID: 120249
Summary: Improve handling of comments with -C similarly to
clang
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: preprocessor
Assignee: unassigned at gcc dot gnu.org
Reporter: federico at kircheis dot it
Target Milestone: ---
Consider following program
----
#define CPP_PP_CAT_(X, ...) X ## __VA_ARGS__
#define CPP_PP_CAT(X, ...) CPP_PP_CAT_(X, __VA_ARGS__)
int bar(){
// comment 1
int /*comment2*/ CPP_PP_CAT(a, // comment 3
b) = 12; // comment4
return ab;
}
----
GCC, when using "-E -C" triggers the error
> pasting "a" and "/* comment 3*/" does not give a valid preprocessing token
Which is correct.
On the other hand, clang also supports "-E -C" and discards "// comment 3" to
let the proprocessor do its work, but keeps all other comments.
Since the (documented) intended usage for "-C" is to keep comments relevant for
linters, it should be better if a comments is discarded instead of retained and
leading to an error.
Especially since the comment might be irrelevant for the linter.
Example on godbolt: https://godbolt.org/z/1h858bnaW
