This reverts commit 22e2db6010b029ebd4c6d3d1fd30224d8b3109ef.
Broke buildbots on Windows. It seems standard headers on Windows contain
flexible array members in unions
It was rejected in C, and in a strange way accepted in C++. However, the
support was never properly tested and fully implemented, so just reject
it in C++ mode as well.
This change also fixes crash on attempt to initialize union with flexible
array member. Due to missing check on union, there was a null expression
added to init list that caused crash later.
Fixes https://github.com/llvm/llvm-project/issues/61746
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D147626
Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.
Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).
This was originally committed in 277623f4d5a672d707390e2c3eaf30a9eb4b075c
Reverted in f9ad1d1c775a8e264bebc15d75e0c6e5c20eefc7 due to breakages
outside of clang - lldb seems to have some strange/strong dependence on
"char [N]" versus "char[N]" when printing strings (not due to that name
appearing in DWARF, but probably due to using clang to stringify type
names) that'll need to be addressed, plus a few other odds and ends in
other subprojects (clang-tools-extra, compiler-rt, etc).
Looks like lldb has some issues with this - somehow it causes lldb to
treat a "char[N]" type as an array of chars (prints them out
individually) but a "char [N]" is printed as a string. (even though the
DWARF doesn't have this string in it - it's something to do with the
string lldb generates for itself using clang)
This reverts commit 277623f4d5a672d707390e2c3eaf30a9eb4b075c.
Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.
Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).
Allow Obj-C ivars with incomplete array type but only as the last ivar.
Also add a requirement for ivars that contain a flexible array member to
be at the end of class too. It is possible to add in a subclass another
ivar at the end but we'll emit a warning in this case. Also we'll emit a
warning if a variable sized ivar is declared in class extension or in
implementation because subclasses won't know they should avoid adding
new ivars.
In ARC incomplete array objects are treated as __unsafe_unretained so
require them to be marked as such.
Prohibit synthesizing ivars with flexible array members because order of
synthesized ivars is not obvious and tricky to control. Spelling out
ivar explicitly gives control to developers and helps to avoid surprises
with unexpected ivar ordering.
For C and C++ changed diagnostic to tell explicitly a field is not the
last one and point to the next field. It is not as useful as in Obj-C
but it is an improvement and it is consistent with Obj-C. For C for
unions emit more specific err_flexible_array_union instead of generic
err_field_incomplete.
rdar://problem/21054495
Reviewers: rjmccall, theraven
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D38773
llvm-svn: 316381
A record which contains a flexible array member is itself a flexible
array member. A struct which contains such a record should also
consider itself to be a flexible array member.
llvm-svn: 218378
rules: instead of requiring flexible array members to be POD, require them to
be trivially-destructible. This seems to be the only constraint that actually
matters here (and even then, it's questionable whether this matters).
llvm-svn: 198983
Flexible array members only work out if they are the last field of a
record, however virtual bases would give us many situations where the
flexible array member would overlap with the virtual base fields.
It is unlikely in the extreme that this behavior was intended by the
user so raise a diagnostic instead of accepting. This is will not
reject conforming code because flexible array members are an extension
in C++ mode.
llvm-svn: 193920
