https://gcc.gnu.org/onlinedocs/gcc/Typeof.html
Differences from the GCC extension:
* __auto_type is also permitted in C++ (but only in places where
it could appear in C), allowing its use in headers that might
be shared across C and C++, or used from C++98
* __auto_type can be combined with a declarator, as with C++ auto
(for instance, "__auto_type *p")
* multiple variables can be declared in a single __auto_type
declaration, with the C++ semantics (the deduced type must be
the same in each case)
This patch also adds a missing restriction on applying typeof to
a bit-field, which GCC has historically rejected in C (due to
lack of clarity as to whether the operand should be promoted).
The same restriction also applies to __auto_type in C (in both
GCC and Clang).
This also fixes PR25449.
Patch by Nicholas Allegra!
llvm-svn: 252690
when the RHS of the ||/&& is ever 0 or 1. This handles a variety of
creative idioms for "true" used in C programs and fixes many false
positives at the expense of a few false negatives. This fixes
rdar://8230351.
llvm-svn: 109314
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
we don't have enough information to tell them how to use 'strncmp'. Instead, change the
diagnostic to indicate they should use 'strncmp'.
llvm-svn: 100890
unevaluated contexts, because they only matter for code that will
actually be evaluated at runtime.
As part of this, I had to extend PartialDiagnostic to support fix-it
hints.
llvm-svn: 93266
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
implements a framework that allows us to use information about previously
substituted values to simplify subsequent ones. Maybe this would be useful
for C++'y stuff, who knows. We now get:
t.c:4:21: error: invalid operands to binary expression ('size_t' (aka 'unsigned long *') and 'size_t')
return (size_t) 0 + (size_t) 0;
~~~~~~~~~~ ^ ~~~~~~~~~~
on the testcase. Note that size_t is only aka'd once.
llvm-svn: 84604
-Makes typeof consistent with sizeof/alignof
-Fixes a bug when '>' is in a typeof expression, inside a template type param:
A<typeof(x>1)> a;
llvm-svn: 72255
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
- Strip off extra parens when looking for casts.
- Change the location info to point at the cast (instead of the
assignment).
For example, on
int *b;
#define a ((void*) b)
void f0() {
a = 10;
}
we now emit:
/tmp/t.c:4:3: error: assignment to cast is illegal, lvalue casts are not supported
a = 10;
^ ~
/tmp/t.c:2:12: note: instantiated from:
#define a ((void*) b)
~^~~~~~~~~~
instead of:
/tmp/t.c:4:5: error: expression is not assignable
a = 10;
~ ^
llvm-svn: 69114
clang.
- We will eventually want some more driver infrastructre for this
probably.
- For now, the clang-cc interface stays relatively the same, but we
don't accept multiple instances anymore, or the [no-] variants
directly.
llvm-svn: 68550
information about types. We often print diagnostics where we say
"foo_t" is bad, but the user doesn't know how foo_t is declared
(because it is a typedef). Fix this by expanding sugar when present
in a diagnostic (and not one of a few special cases, like vectors).
Before:
t.m:5:2: error: invalid operands to binary expression ('typeof(P)' and 'typeof(F)')
MAX(P, F);
^~~~~~~~~
t.m:1:78: note: instantiated from:
#define MAX(A,B) ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
^
After:
t.m:5:2: error: invalid operands to binary expression ('typeof(P)' (aka 'struct mystruct') and 'typeof(F)' (aka 'float'))
MAX(P, F);
^~~~~~~~~
t.m:1:78: note: instantiated from:
#define MAX(A,B) ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
^
llvm-svn: 65081
Richard Smith