* support the gcc __builtin_constant_p() ? ... : ... folding hack in C++11
* check for unspecified values in pointer comparisons and pointer subtractions
llvm-svn: 149578
argument in strncat.
The warning is ignored by default since it needs more qualification.
TODO: The warning message and the note are messy when
strncat is a builtin due to the macro expansion.
llvm-svn: 149524
This is a mess. According to the C++11 standard, pointer subtraction only has
undefined behavior if the difference of the array indices does not fit into a
ptrdiff_t.
However, common implementations effectively perform a char* subtraction first,
and then divide the result by the element size, which can cause overflows in
some cases. Those cases are not considered to be undefined behavior by this
change; perhaps they should be.
llvm-svn: 149490
mangling of floating-point literals. I just went ahead and
reimplemented toString() here; if someone wants to generalize
the library routine to do this, or feels strongly that we should
be post-processing, please feel free.
llvm-svn: 149256
function definition can produce a constant expression. This also provides the
last few checks for [dcl.constexpr]p3 and [dcl.constexpr]p4.
llvm-svn: 149108
provide the layout of records, rather than letting Clang compute
the layout itself. LLDB provides the motivation for this feature:
because various layout-altering attributes (packed, aligned, etc.)
don't get reliably get placed into DWARF, the record layouts computed
by LLDB from the reconstructed records differ from the actual layouts,
and badness occurs. This interface lets the DWARF data drive layout,
so we don't need the attributes preserved to get the answer write.
The testing methodology for this change is fun. I've introduced a
variant of -fdump-record-layouts called -fdump-record-layouts-simple
that always has the simple C format and provides size/alignment/field
offsets. There is also a -cc1 option -foverride-record-layout=<file>
to take the output of -fdump-record-layouts-simple and parse it to
produce a set of overridden layouts, which is introduced into the AST
via a testing-only ExternalASTSource (called
LayoutOverrideSource). Each test contains a number of records to lay
out, which use various layout-changing attributes, and then dumps the
layouts. We then run the test again, using the preprocessor to
eliminate the layout-changing attributes entirely (which would give us
different layouts for the records), but supplying the
previously-computed record layouts. Finally, we diff the layouts
produced from the two runs to be sure that they are identical.
Note that this code makes the assumption that we don't *have* to
provide the offsets of bases or virtual bases to get the layout right,
because the alignment attributes don't affect it. I believe this
assumption holds, but if it does not, we can extend
LayoutOverrideSource to also provide base offset information.
Fixes the Clang side of <rdar://problem/10169539>.
llvm-svn: 149055
iff its substitution contains an unexpanded parameter pack. This has the effect
that we now reject declarations such as this (which we used to crash when
expanding):
template<typename T> using Int = int;
template<typename ...Ts> void f(Int<Ts> ...ints);
The standard is inconsistent on how this case should be treated.
llvm-svn: 148905
for it to be used in converted constant expression checking, and fix a couple
of issues:
- Conversion operators implicitly invoked prior to the narrowing conversion
were not being correctly handled when determining whether a constant value
was narrowed.
- For conversions from floating-point to integral types, the diagnostic text
incorrectly always claimed that the source expression was not a constant
expression.
llvm-svn: 148381
for FunctionDecl::getMemoryFunctionKind().
This is a follow up on the Chris's review for r148142: We don't want to
pollute FunctionDecl with an extra enum. (To make this work, added
memcmp and family to the library builtins.)
llvm-svn: 148267
- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type. This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks. The feature isn't 100% complete yet, but it's done enough that we want people testing it.
Still to do:
- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases
llvm-svn: 148242
protocol, record the definition pointer in the canonical declaration
for that entity, and then propagate that definition pointer from the
canonical declaration to all other deserialized declarations. This
approach works well even when deserializing declarations that didn't
know about the original definition, which can occur with modules.
A nice bonus from this definition-deserialization approach is that we
no longer need update records when a definition is added, because the
redeclaration chains ensure that the if any declaration is loaded, the
definition will also get loaded.
llvm-svn: 148223
we have a redeclarable type, and only use the new virtual versions
(getPreviousDeclImpl() and getMostRecentDeclImpl()) when we don't have
that type information. This keeps us from penalizing users with strict
type information (and is the moral equivalent of a "final" method).
Plus, settle on the names getPreviousDecl() and getMostRecentDecl()
throughout.
llvm-svn: 148187
Richard Smith