This implementation doesn't warn on anything that GCC doesn't warn on with the
exception of templates specializations (GCC doesn't warn, Clang does). The
specific skipped cases (boolean, constant expressions, enums) are open for
debate/adjustment if anyone wants to demonstrate that GCC is being overly
conservative here. The only really obvious false positive I found was in the
Clang regression suite's MPI test - apparently MPI uses specific flag values in
pointer constants. (eg: #define FOO (void*)~0)
llvm-svn: 166039
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.
Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.
In passing, fix static_assert to perform a contextual conversion to bool on its
argument.
llvm-svn: 149776
whether an expression is a (core) constant expression as a side-effect of
evaluation. This takes us from accepting far too few expressions as ICEs to
accepting slightly too many -- fixes for the remaining cases are coming next.
The diagnostics produced when an expression is found to be non-constant are
currently quite poor (with generic wording but reasonable source locations),
and will be improved in subsequent commits.
llvm-svn: 146289
as constant size arrays. This has slightly different semantics in some insane cases, but allows
us to accept some constructs that GCC does. Continue to be pedantic in -std=c99 and other
modes. This addressed rdar://8733881 - error "variable-sized object may not be initialized"; g++ accepts same code
llvm-svn: 132983
diagnostics that occur in unreachable code (e.g., -Warray-bound).
We only pay the cost of doing the reachability analysis when we issue one of these diagnostics.
llvm-svn: 126290
t2.c:2:12: warning: use of logical && with constant operand; switch to bitwise &
or remove constant [-Wlogical-bitwise-confusion]
return x && 4;
^ ~
wording improvement suggestions are welcome.
llvm-svn: 108260
As a bonus, fix the warning for || and && operators; it was emitted even if one of the operands had side effects, e.g:
x || test_logical_foo1();
emitted a bogus "expression result unused" for 'x'.
llvm-svn: 107274
scheme to be more useful.
The new scheme introduces a set of categories that should be more
readable, and also reflects what we want to consider as an extension
more accurately. Specifically, it makes the "what is a keyword"
determination accurately reflect whether the keyword is a GNU or
Microsoft extension.
I also introduced separate flags for keyword aliases; this is useful
because the classification of the aliases is mostly unrelated to the
classification of the original keyword.
This patch treats anything that's in the implementation
namespace (prefixed with "__", or "_X" where "X" is any upper-case
letter) as a keyword without marking it as an extension. This is
consistent with the standards in that an implementation is allowed to define
arbitrary extensions in the implementation namespace without violating
the standard. This gets rid of all the nasty "extension used" warnings
for stuff like __attribute__ in -pedantic mode. We still warn for
extensions outside of the the implementation namespace, like typeof.
If someone wants to implement -Wextensions or something like that, we
could add additional information to the keyword table.
This also removes processing for the unused "Boolean" language option;
such an extension isn't supported on any other C implementation, so I
don't see any point to adding it.
The changes to test/CodeGen/inline.c are required because previously, we
weren't actually disabling the "inline" keyword in -std=c89 mode.
I'll remove Boolean and NoExtensions from LangOptions in a follow-up
commit.
llvm-svn: 70281
Richard Smith