[cpp.cond]p4:
Prior to evaluation, macro invocations in the list of preprocessing
tokens that will become the controlling constant expression are replaced
(except for those macro names modified by the 'defined' unary operator),
just as in normal text. If the token 'defined' is generated as a result
of this replacement process or use of the 'defined' unary operator does
not match one of the two specified forms prior to macro replacement, the
behavior is undefined.
This isn't an idle threat, consider this program:
#define FOO
#define BAR defined(FOO)
#if BAR
...
#else
...
#endif
clang and gcc will pick the #if branch while Visual Studio will take the
#else branch. Emit a warning about this undefined behavior.
One problem is that this also applies to function-like macros. While the
example above can be written like
#if defined(FOO) && defined(BAR)
#defined HAVE_FOO 1
#else
#define HAVE_FOO 0
#endif
there is no easy way to rewrite a function-like macro like `#define FOO(x)
(defined __foo_##x && __foo_##x)`. Function-like macros like this are used in
practice, and compilers seem to not have differing behavior in that case. So
this a default-on warning only for object-like macros. For function-like
macros, it is an extension warning that only shows up with `-pedantic`.
(But it's undefined behavior in both cases.)
llvm-svn: 258128
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
llvm-svn: 240270
clang::MacroDefinition now models the currently-defined value of a macro. The
previous MacroDefinition type, which represented a record of a macro definition
directive for a detailed preprocessing record, is now called MacroDefinitionRecord.
llvm-svn: 236400
Modules builds fundamentally have a non-linear macro history. In the interest
of better source fidelity, represent the macro definition information
faithfully: we have a linear macro directive history within each module, and at
any point we have a unique "latest" local macro directive and a collection of
visible imported directives. This also removes the attendent complexity of
attempting to create a correct MacroDirective history (which we got wrong
in the general case).
No functionality change intended.
llvm-svn: 236176
(for an integer too large for any signed type) from Warning to ExtWarn -- it's
ill-formed in C++11 and C99 onwards, and UB during translation in C89 and
C++98. Add diagnostic groups for two relevant diagnostics.
llvm-svn: 203974
This is approaching consistency but the PP and Parse categories they still have
slightly different wording:
def err_pp_expected_after : Error<"missing %1 after %0">;
def err_expected_after : Error<"expected %1 after %0">;
llvm-svn: 198189
Introduce proper facilities to render token spellings using the diagnostic
formatter.
Replaces most of the hard-coded diagnostic messages related to expected tokens,
which all shared the same semantics but had to be multiply defined due to
variations in token order or quote marks.
The associated parser changes are largely mechanical but they expose
commonality in whole chunks of the parser that can now be factored away.
This commit uses C++11 typed enums along with a speculative legacy fallback
until the transition is complete.
Requires corresponding changes in LLVM r197895.
llvm-svn: 197972
It turns out that Plum Hall depends on us not emitting an error on
integer literals which fit into long long, but fit into
unsigned long long. So C99 conformance requires not conforming to C99. :)
llvm-svn: 187172
Switch some warnings over to errors which should never have been warnings
in the first place. (Also, a minor fix to the preprocessor rules for
integer literals while I'm here.)
llvm-svn: 186903
For each macro directive (define, undefine, visibility) have a separate object that gets chained
to the macro directive history. This has several benefits:
-No need to mutate a MacroDirective when there is a undefine/visibility directive. Stuff like
PPMutationListener become unnecessary.
-No need to keep extra source locations for the undef/visibility locations for the define directive object
(which is the majority of the directives)
-Much easier to hide/unhide a section in the macro directive history.
-Easier to track the effects of the directives across different submodules.
llvm-svn: 178037
The previous implementation missed the case where the elif condition was
evaluated from the context of an #ifdef that was false causing PR15539.
llvm-svn: 177345
uncovered.
This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.
I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.
llvm-svn: 169237
grammar requires a string-literal and not a user-defined-string-literal. The
two constructs are still represented by the same TokenKind, in order to prevent
a combinatorial explosion of different kinds of token. A flag on Token tracks
whether a ud-suffix is present, in order to prevent clients from needing to look
at the token's spelling.
llvm-svn: 152098
This also adds a -Wc++98-compat-pedantic for warning on constructs which would
be diagnosed by -std=c++98 -pedantic (that is, it warns even on C++11 features
which we enable by default, with no warning, in C++98 mode).
llvm-svn: 142034
Previously we would cut off the source file buffer at the code-completion
point; this impeded code-completion inside C++ inline methods and,
recently, with buffering ObjC methods.
Have the code-completion inserted into the source buffer so that it can
be buffered along with a method body. When we actually hit the code-completion
point the cut-off lexing or parsing.
Fixes rdar://10056932&8319466
llvm-svn: 139086
1. Be more tolerant of comments in -CC (comment-preserving) mode. We were missing a few cases.
2. Make sure to expand the second FOO in "#if defined FOO FOO". (See also
r97253, which addressed the case of "#if defined(FOO FOO".)
Fixes PR10286.
llvm-svn: 136748
Eugene Zelenko