What we want to actually control this behavior is something more local
than an EvalutationMode. Please see the linked revision for more
discussion on why/etc.
This fixes PR31843.
Differential Revision: https://reviews.llvm.org/D29469
llvm-svn: 294800
Summary:
This teaches clang how to parse and lower the 'interrupt' and 'naked'
attributes.
This allows interrupt signal handlers to be written.
Reviewers: aaron.ballman
Subscribers: malcolm.parsons, cfe-commits
Differential Revision: https://reviews.llvm.org/D28451
llvm-svn: 294402
My original warning was very conservative and I never revisited the
heuristics that were used.
This would have caught http://crbug.com/687251 at compile time.
llvm-svn: 293677
Don't try to map an APSInt addend to an int64_t in pointer arithmetic before
bounds-checking it. This gives more consistent behavior (outside C++11, we
consistently use 2s complement semantics for both pointer and integer overflow
in constant expressions) and fixes some cases where in C++11 we would fail to
properly check for out-of-bounds pointer arithmetic (if the 2s complement
64-bit overflow landed us back in-bounds).
In passing, also fix some cases where we'd perform possibly-overflowing
arithmetic on CharUnits (which have a signed underlying type) during constant
expression evaluation.
llvm-svn: 293595
This fixes various ways to tickle an assertion in constant expression
evaluation when using __int128. Longer term, we need to figure out what should
happen here: either any kind of overflow in offset calculation should result in
a non-constant value or we should truncate to 64 bits. In C++11 onwards, we're
effectively already checking for overflow because we strictly enforce array
bounds checks, but even there some forms of overflow can slip past undetected.
llvm-svn: 293568
This patch changes how we handle argument-dependent `diagnose_if`
attributes. In particular, we now check them in the same place that we
check for things like passing NULL to Nonnull args, etc. This is
basically better in every way than how we were handling them before. :)
This fixes PR31638, PR31639, and PR31640.
Differential Revision: https://reviews.llvm.org/D28889
llvm-svn: 293360
The idea for this originated from a really tricky bug: ISRs on ARM don't
automatically save off the VFP regs, so if say, memcpy gets interrupted and the
ISR itself calls memcpy, the regs are left clobbered when the ISR is done.
https://reviews.llvm.org/D28820
llvm-svn: 292375
Summary: In order for libc++ to meaningfully use `diagnose_if` warnings they need to be emitted from system headers by default. This patch changes the `diagnose_if` warning diagnostic to be shown in system headers.
Reviewers: george.burgess.iv, rsmith, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28703
llvm-svn: 291963
the same source range and use the unary operator fixit only when it
actually silences the warning.
rdar://24570531
Differential Revision: https://reviews.llvm.org/D28231
llvm-svn: 291757
Correct the logic used to set ATOMIC_*_LOCK_FREE preprocessor macros not
to rely on the ABI alignment of types. Instead, just assume all those
types are aligned correctly by default since clang uses safe alignment
for _Atomic types even if the underlying types are aligned to a lower
boundary by default.
For example, the 'long long' and 'double' types on x86 are aligned to
32-bit boundary by default. However, '_Atomic long long' and '_Atomic
double' are aligned to 64-bit boundary, therefore satisfying
the requirements of lock-free atomic operations.
This fixes PR #19355 by correcting the value of
__GCC_ATOMIC_LLONG_LOCK_FREE on x86, and therefore also fixing
the assumption made in libc++ tests. This also fixes PR #30581 by
applying a consistent logic between the functions used to implement
both interfaces.
Differential Revision: https://reviews.llvm.org/D28213
llvm-svn: 291477
`diagnose_if` can be used to have clang emit either warnings or errors
for function calls that meet user-specified conditions. For example:
```
constexpr int foo(int a)
__attribute__((diagnose_if(a > 10, "configurations with a > 10 are "
"expensive.", "warning")));
int f1 = foo(9);
int f2 = foo(10); // warning: configuration with a > 10 are expensive.
int f3 = foo(f2);
```
It currently only emits diagnostics in cases where the condition is
guaranteed to always be true. So, the following code will emit no
warnings:
```
constexpr int bar(int a) {
foo(a);
return 0;
}
constexpr int i = bar(10);
```
We hope to support optionally emitting diagnostics for cases like that
(and emitting runtime checks) in the future.
Release notes will appear shortly. :)
Differential Revision: https://reviews.llvm.org/D27424
llvm-svn: 291418
FunctionDecls.
This commit silences an incorrect warning that is issued when a function
pointer is cast to another function pointer type. The warning gets
issued because alignments of the source and destination do not match in
Sema::CheckCastAlign, which happens because ASTContext::getTypeInfoImpl
and ASTContext::getDeclAlign return different values for functions (the
former returns 4 while the latter returns 1).
This should fix PR31558.
rdar://problem/29533528
Differential Revision: https://reviews.llvm.org/D27478
llvm-svn: 291253
This change avoids the -Wstrict-prototypes warning for block literals with an
empty argument list or without argument lists.
rdar://15060615
Differential Revision: https://reviews.llvm.org/D28296
llvm-svn: 291231
Without this, we drop everything after the first late-parsed attribute
in a single __attribute__. (Where "drop" means "stuff everything into
LA->Toks.")
llvm-svn: 291020
Previously, -Wtautological-overlap-compare did not warn on cases where the
boolean expression was in an assignment or return statement. This patch
should cause all boolean statements to be passed to the tautological compare
checks in the CFG analysis.
This is one of the issues from PR13101
llvm-svn: 290920
According to extended asm syntax, a case where the clobber list includes a variable from the inputs or outputs should be an error - conflict.
for example:
const long double a = 0.0;
int main()
{
char b;
double t1 = a;
__asm__ ("fucompp": "=a" (b) : "u" (t1), "t" (t1) : "cc", "st", "st(1)");
return 0;
}
This should conflict with the output - t1 which is st, and st which is st aswell.
The patch fixes it.
Commit on behald of Ziv Izhar.
Differential Revision: https://reviews.llvm.org/D15075
llvm-svn: 290539
I don't remember why I didn't make alloc_size only applicable to
Functions a year ago, but I can't see any compelling reason not to do
so now.
Fixes PR31453.
llvm-svn: 290353
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.
Fingers crossed that this patch sticks this time. :)
Original commit message:
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
llvm-svn: 290297
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.
George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.
llvm-svn: 290169
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
Differential Revision: https://reviews.llvm.org/D14274
llvm-svn: 290149
* In C++, never create a FunctionNoProtoType for a builtin (fixes C++1z
crasher from r289754).
* Fix type of __sync_synchronize to be a no-parameter function rather than a
varargs function. This matches GCC.
* Fix type of vfprintf to match its actual type. We gave it a wrong type due
to PR4290 (apparently autoconf generates invalid code and expects compilers
to choke it down or it miscompiles the program; the relevant error in clang
was downgraded to a warning in r122744 to fix other occurrences of this
autoconf brokenness, so we don't need this workaround any more).
* Turn off vararg argument checking for __noop, since it's not *really* a
varargs function. Alternatively we could add custom type checking for it
and synthesize parameter types matching the actual arguments in each call,
but that seemed like overkill.
llvm-svn: 290146
r289225 broke AST invariants by reparenting enumerators into function
decl contexts. This improves things by only reparenting TagDecls while
also attempting to preserve the lexical declcontext chain. The
interesting example here is:
int f(struct S { enum E { a = 1 } b; } c);
The semantic contexts of E and S should be f, and the lexical context of
S should be f and the lexical context of E should be S. We didn't do
that with r289225, but now we should.
This change should also improve our behavior on this example:
void f() {
extern void ext(struct S { } o);
// S injected here
}
Before r289225 we would only remove 'S' from the surrounding tag
injection context if it was the TU, but now we properly reparent S from
f to ext.
Fixes PR31366
llvm-svn: 289678
This saves two pointers from FunctionDecl that were being used for some
rare and questionable C-only functionality. The DeclsInPrototypeScope
ArrayRef was added in r151712 in order to parse this kind of C code:
enum e {x, y};
int f(enum {y, x} n) {
return x; // should return 1, not 0
}
The challenge is that we parse 'int f(enum {y, x} n)' it its own
function prototype scope that gets popped before we build the
FunctionDecl for 'f'. The original change was doing two questionable
things:
1. Saving all tag decls introduced in prototype scope on a TU-global
Sema variable. This is problematic when you have cases like this, where
'x' and 'y' shouldn't be visible in 'f':
void f(void (*fp)(enum { x, y } e)) { /* no x */ }
This patch fixes that, so now 'f' can't see 'x', which is consistent
with GCC.
2. Storing the decls in FunctionDecl in ActOnFunctionDeclarator so that
they could be used in ActOnStartOfFunctionDef. This is just an
inefficient way to move information around. The AST lives forever, but
the list of non-parameter decls in prototype scope is short lived.
Moving these things to the Declarator solves both of these issues.
Reviewers: rsmith
Subscribers: jmolloy, cfe-commits
Differential Revision: https://reviews.llvm.org/D27279
llvm-svn: 289225
This commit fixes PR20796. It implements the C only -Wstrict-prototypes warning.
Clang now emits a warning for function declarations which have no parameters
specified and for K&R function definitions with more than 0 parameters that are
not preceded by a previous prototype declaration.
The patch was originally submitted by Paul Titei!
rdar://15060615
Differential Revision: https://reviews.llvm.org/D16533
llvm-svn: 288896
We should complain about the following:
```
void foo() __attribute__((unavailable("a", "b")));
```
Instead, we currently just ignore "b". (...We also end up ignoring "a",
because we assume elsewhere that this attribute can only have 1 or 0
args.)
This happens because `unavailable` has a fake enum arg, and
`AttributeList::{getMinArgs,getMaxArgs}` include fake args in their
counts.
llvm-svn: 288388
declared variables.
Teach Sema to check the aligned attribute attached to variable
declarations so that it doesn't issue spurious warnings.
rdar://problem/26517471
Differential revision: https://reviews.llvm.org/D21099
llvm-svn: 288267
This commit teaches clang that is has to emit a warning when NULL is passed
as the 'expected' pointer parameter into an atomic compare exchange call.
rdar://18926650
Differential Revision: https://reviews.llvm.org/D26978
llvm-svn: 287776
Summary:
This is a simple sema check patch for arguments of `__builtin_arm_rsr` and the related builtins, which currently do not allow special registers with indexes >7.
Some of the possible register name formats these builtins accept are:
```
{c}p<coprocessor>:<op1>:c<CRn>:c<CRm>:<op2>
```
```
o0:op1:CRn:CRm:op2
```
where `op1` / `op2` are integers in the range [0, 7] and `CRn` / `CRm` are integers in the range [0, 15].
The current sema check does not allow `CRn` > 7 and accepts `op2` up to 15.
Reviewers: LukeCheeseman, rengolin
Subscribers: asl, aemerson, rengolin, cfe-commits
Differential Revision: https://reviews.llvm.org/D26464
llvm-svn: 287378
ExpectedFunctionGlobalVarMethodOrProperty
would previously say "functions and global variables"
instead of "functions, methods, properties, and global variables"
The newly added ExpectedFunctionOrGlobalVariable
says "functions and global variables"
Differential Revision: https://reviews.llvm.org/D26459
llvm-svn: 286599
Since array parameters decay to pointers, '_Nullable' and friends
should be available for use there as well. This is especially
important for parameters that are typedefs of arrays. The unsugared
syntax for this follows the syntax for 'static'-sized arrays in C:
void test(int values[_Nullable]);
This syntax was previously accepted but the '_Nullable' (and any other
attributes) were silently discarded. However, applying '_Nullable' to
a typedef was previously rejected and is now accepted; therefore, it
may be necessary to test for the presence of this feature:
#if __has_feature(nullability_on_arrays)
One important change here is that DecayedTypes don't always
immediately contain PointerTypes anymore; they may contain an
AttributedType instead. This only affected one place in-tree, so I
would guess it's not likely to cause problems elsewhere.
This commit does not change -Wnullability-completeness just yet. I
want to think about whether it's worth doing something special to
avoid breaking existing clients that compile with -Werror. It also
doesn't change '#pragma clang assume_nonnull' behavior, which
currently treats the following two declarations as equivalent:
#pragma clang assume_nonnull begin
void test(void *pointers[]);
#pragma clang assume_nonnull end
void test(void * _Nonnull pointers[]);
This is not the desired behavior, but changing it would break
backwards-compatibility. Most likely the best answer is going to be
adding a new warning.
Part of rdar://problem/25846421
llvm-svn: 286519
the body of a function for the purposes of computing its storage
duration and deciding whether its initializer must be constant.
There are a number of problems in our current treatment of compound
literals. C specifies that a compound literal yields an l-value
referring to an object with either static or automatic storage
duration, depending on where it was written; in the latter case,
the literal object has a lifetime tied to the enclosing scope (much
like an ObjC block), not the enclosing full-expression. To get these
semantics fully correct in our current design, we would need to
collect compound literals on the ExprWithCleanups, just like we do
with ObjC blocks; we would probably also want to identify literals
like we do with materialized temporaries. But it gets stranger;
GCC adds compound literals to C++ as an extension, but makes them
r-values, which are generally assumed to have temporary storage
duration. Ignoring destructor ordering, the difference only matters
if the object's address escapes the full-expression, which for an
r-value can only happen with reference binding (which extends
temporaries) or array-to-pointer decay (which does not). GCC then
attempts to lock down on array-to-pointer decay in ad hoc ways.
Arguably a far superior language solution for C++ (and perhaps even
array r-values in C, which can occur in other ways) would be to
propagate lifetime extension through array-to-pointer decay, so
that initializing a pointer object to a decayed r-value array
extends the lifetime of the complete object containing the array.
But this would be a major change in semantics which arguably ought
to be blessed by the committee(s).
Anyway, I'm not fixing any of that in this patch; I did try, but
it got out of hand.
Fixes rdar://28949016.
llvm-svn: 285643
The second argument to __builtin_alloca_with_align is supposed to be in
bits, not bytes. Using alignof there would be indicative of a bug.
llvm-svn: 285609
__builtin_alloca always uses __BIGGEST_ALIGNMENT__ for the alignment of
the allocation. __builtin_alloca_with_align allows the programmer to
specify the alignment of the allocation.
This fixes PR30658.
llvm-svn: 285544
If we pass a header to libclang, e.g. because it's open in an editor in
an IDE, warnings about unused const vars are not useful: other files
that include the header might use those constants. So when -x *-header
is passed as command-line option, suppress this warning.
llvm-svn: 285386
Warnings generated by -Wdocumentation-unknown-command did only have a
start location, not a full source range. This resulted in only the
"carret" being show in messages, and IDEs highlighting only the single
initial character.
llvm-svn: 285056
Gcc prints error if elements of left and right parts of a shift have different
sizes. This patch is provided the GCC compatibility.
Patch by Vladimir Yakovlev.
Differential Revision: https://reviews.llvm.org/D24669
llvm-svn: 284579
Aaron Ballman