When a non-trivial parameter is present, clang now gathers up all the
parameters that lack inreg and puts them into a packed struct. MSVC
always aligns each parameter to 4 bytes and no more, so this is a pretty
simple struct to lay out.
On win64, non-trivial records are passed indirectly. Prior to this
change, clang was incorrectly using byval on win64.
I'm able to self-host a working clang with this change and additional
LLVM patches.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D2636
llvm-svn: 200597
This fixes PR15768, where the sret parameter and the 'this' parameter
are in the wrong order.
Instance methods compiled by MSVC never return records in registers,
they always return indirectly through an sret pointer. That sret
pointer always comes after the 'this' parameter, for both __cdecl and
__thiscall methods.
Unfortunately, the same is true for other calling conventions, so we'll
have to change the overall approach here relatively soon.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D2664
llvm-svn: 200587
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
Fix a perennial source of confusion in the clang type system: Declarations and
function prototypes have parameters to which arguments are supplied, so calling
these 'arguments' was a stretch even in C mode, let alone C++ where default
arguments, templates and overloading make the distinction important to get
right.
Readability win across the board, especially in the casting, ADL and
overloading implementations which make a lot more sense at a glance now.
Will keep an eye on the builders and update dependent projects shortly.
No functional change.
llvm-svn: 199686
There are a number of places where we do PGO.setCurrentRegionCount(0)
directly after an unconditional branch. Give this operation a name so
that it's clearer why we're doing this.
llvm-svn: 199138
Unlike Itanium's VTTs, the 'most derived' boolean or bitfield is the
last parameter for non-variadic constructors, rather than the second.
For variadic constructors, the 'most derived' parameter comes after the
'this' parameter. This affects constructor calls and constructor decls
in a variety of places.
Reviewers: timurrrr
Differential Revision: http://llvm-reviews.chandlerc.com/D2405
llvm-svn: 197518
Summary:
MSVC destroys arguments in the callee from left to right. Because C++
objects have to be destroyed in the reverse order of construction, Clang
has to construct arguments from right to left and destroy arguments from
left to right.
This patch fixes the ordering by reversing the order of evaluation of
all call arguments under the MS C++ ABI.
Fixes PR18035.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D2275
llvm-svn: 196402
CodeGenABITypes is a wrapper built on top of CodeGenModule that exposes
some of the functionality of CodeGenTypes (held by CodeGenModule),
specifically methods that determine the LLVM types appropriate for
function argument and return values.
I addition to CodeGenABITypes.h, CGFunctionInfo.h is introduced, and the
definitions of ABIArgInfo, RequiredArgs, and CGFunctionInfo are moved
into this new header from the private headers ABIInfo.h and CGCall.h.
Exposing this functionality is one part of making it possible for LLDB
to determine the actual ABI locations of function arguments and return
values, making it possible for it to determine this for any supported
target without hard-coding ABI knowledge in the LLDB code.
llvm-svn: 193717
CodeGenTypes already has a reference to a CGCXXABI. Use this directly
rather than going through CodeGenModule to get to the same information.
This is consistent with other references to CGCXXABI in CodeGenTypes
functions defined in CGCall.cpp.
llvm-svn: 191854
Summary:
Makes functions with implicit calling convention compatible with
function types with a matching explicit calling convention. This fixes
things like calls to qsort(), which has an explicit __cdecl attribute on
the comparator in Windows headers.
Clang will now infer the calling convention from the declarator. There
are two cases when the CC must be adjusted during redeclaration:
1. When defining a non-inline static method.
2. When redeclaring a function with an implicit or mismatched
convention.
Fixes PR13457, and allows clang to compile CommandLine.cpp for the
Microsoft C++ ABI.
Excellent test cases provided by Alexander Zinenko!
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1231
llvm-svn: 189412
This allows clang to use the backend parameter attribute 'returned' when generating 'this'-returning constructors and destructors in ARM and MSVC C++ ABIs.
llvm-svn: 185291
Itanium destroys them in the caller at the end of the full expression,
but MSVC destroys them in the callee. This is further complicated by
the need to emit EH-only destructor cleanups in the caller.
This should help clang compile MSVC's debug iterators more correctly.
There is still an outstanding issue in PR5064 of a memcpy emitted by the
LLVM backend, which is not correct for C++ records.
Fixes PR16226.
Reviewers: rjmccall
Differential Revision: http://llvm-reviews.chandlerc.com/D929
llvm-svn: 184543
The backend will now use the generic 'returned' attribute to form tail calls where possible, as well as avoid save-restores of 'this' in some cases (specifically the cases that matter for the ARM C++ ABI).
This patch also reverts a prior front-end only partial implementation of these optimizations, since it's no longer required.
llvm-svn: 184205
Type coercion for argument passing is equivalent to storing the source
type and loading the destination type from the same pointer. On
big-endian targets, this means that the high bits of integers are
preserved.
This patch fixes the CoerceIntOrPtrToIntOrPtr() function on big-endian
targets by inserting the required shift instructions to preserve the
high bits instead of the low bits.
This is used by SparcABIInfo when passing small structs in the high bits
of registers.
llvm-svn: 183291
The 'inreg' attribute can also be applied to function return values in
LLVM IR. The SPARC v9 backend is using the flag when returning structs
containing 32-bit floats.
llvm-svn: 183290
a lambda.
Bug #1 is that CGF's CurFuncDecl was "stuck" at lambda invocation
functions. Fix that by generally improving getNonClosureContext
to look through lambdas and captured statements but only report
code contexts, which is generally what's wanted. Audit uses of
CurFuncDecl and getNonClosureAncestor for correctness.
Bug #2 is that lambdas weren't specially mapping 'self' when inside
an ObjC method. Fix that by removing the requirement for that
and using the normal EmitDeclRefLValue path in LoadObjCSelf.
rdar://13800041
llvm-svn: 181000
If there is cleanup code, the cleanup code gets the debug location of
the closing '}'. The subsequent ret IR-instruction does not get a
debug location. The return _expression_ will get the debug location
of the return statement.
If the function contains only a single, simple return statement,
the cleanup code may become the first breakpoint in the function.
In this case we set the debug location for the cleanup code
to the location of the return statement.
rdar://problem/13442648
llvm-svn: 180932
CalleeWithThisReturn can be left initialized if HasThisReturn() is false.
This change reverses the order of checks in EmitFunctionEpilog such that
CalleeWithThisReturn is only examined when it has a meaningful value.
Found with MemorySanitizer.
llvm-svn: 178015
to an out-parameter using the indirect-writeback conversion,
and we copied the current value of the variable to the temporary,
make sure that we register an intrinsic use of that value with
the optimizer so that the value won't get released until we have
a chance to retain it.
rdar://13195034
llvm-svn: 177813
For constructors/desctructors that return 'this', if there exists a callsite
that returns 'this' and is immediately before the return instruction, make
sure we are using the return value from the callsite.
We don't need to keep 'this' alive through the callsite. It also enables
optimizations in the backend, such as tail call optimization.
Updated from r177211.
rdar://12818789
llvm-svn: 177541
For constructors/desctructors that return 'this', if there exists a callsite
that returns 'this' and is immediately before the return instruction, make
sure we are using the return value from the callsite.
We don't need to keep 'this' alive through the callsite. It also enables
optimizations in the backend, such as tail call optimization.
rdar://12818789
llvm-svn: 177211
The back-end cannot differentiate between functions that are from a .ll file and
those generated from the front-end. We cannot then take the non-precense of
these attributes as a "false" value. Have the front-end explicitly set the value
to 'true' or 'false' depending upon what is actually set.
llvm-svn: 176985
aggregate types in a profoundly wrong way that has to be
worked around in every call site, to getEvaluationKind,
which classifies and distinguishes between all of these
cases.
Also, normalize the API for loading and storing complexes.
I'm working on a larger patch and wanted to pull these
changes out, but it would have be annoying to detangle
them from each other.
llvm-svn: 176656
[[noreturn]] function are not required to also be [[noreturn]]. We still emit
calls to virtual __attribute__((noreturn)) functions as noreturn; unlike GCC,
we do require overriders to also be noreturn for that attribute.
llvm-svn: 176476
calls and declarations.
LLVM has a default CC determined by the target triple. This is
not always the actual default CC for the ABI we've been asked to
target, and so we sometimes find ourselves annotating all user
functions with an explicit calling convention. Since these
calling conventions usually agree for the simple set of argument
types passed to most runtime functions, using the LLVM-default CC
in principle has no effect. However, the LLVM optimizer goes
into histrionics if it sees this kind of formal CC mismatch,
since it has no concept of CC compatibility. Therefore, if this
module happens to define the "runtime" function, or got LTO'ed
with such a definition, we can miscompile; so it's quite
important to get this right.
Defining runtime functions locally is quite common in embedded
applications.
llvm-svn: 176286
The code generation stuff is going to set attributes on the functions it
generates. To do that it needs the target options. Pass them through.
llvm-svn: 175141
In the future, AttributeWithIndex won't be used anymore. Besides, it exposes the
internals of the AttributeSet to outside users, which isn't goodness.
llvm-svn: 173605
Collections of attributes are handled via the AttributeSet class now. This
finally frees us up to make significant changes to how attributes are structured.
llvm-svn: 173229
it apart from [[gnu::noreturn]] / __attribute__((noreturn)), since their
semantics are not equivalent (for instance, we treat [[gnu::noreturn]] as
affecting the function type, whereas [[noreturn]] does not).
llvm-svn: 172691
directly.
This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.
llvm-svn: 171254
We were emitting calls to blocks as if all arguments were
required --- i.e. with signature (A,B,C,D,...) rather than
(A,B,...). This patch fixes that and accounts for the
implicit block-context argument as a required argument.
In addition, this patch changes the function type under which
we call unprototyped functions on platforms like x86-64 that
guarantee compatibility of variadic functions with unprototyped
function types; previously we would always call such functions
under the LLVM type T (...)*, but now we will call them under
the type T (A,B,C,D,...)*. This last change should have no
material effect except for making the type conventions more
explicit; it was a side-effect of the most convenient implementation.
llvm-svn: 169588
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
Among other differences, GCC accepts
typedef int IA[];
typedef int A10[10];
static A10 *f(void);
static IA *f(void);
void g(void) {
(void)sizeof(*f());
}
but clang used to reject it with:
invalid application of 'sizeof' to an incomplete type 'IA' (aka 'int []')
The intention of c99's 6.2.7 seems to be that we should use the composite type
and accept as gcc does.
Doing the type merging required some extra fixes:
* Use the type from the function type in initializations, even if an parameter
is available.
* Fix the merging of the noreturn attribute in function types.
* Make CodeGen handle the fact that an parameter type can be different from
the corresponding type in the function type.
llvm-svn: 168895
the original parameter or return type.
Since we do not accurately represent the data fields of a union, we should not
directly load or store a union type.
As an exmple, if we have i8,i8, i32, i32 as one field type and i32,i32 as
another field type, the first field type will be chosen to represent the union.
If we load with the union's type, the 3rd byte and the 4th byte will be skipped.
rdar://12723368
llvm-svn: 168820
objc_loadWeak. This retains and autorelease the weakly-refereced
object. This hidden autorelease sometimes makes __weak variable alive even
after the weak reference is erased, because the object is still referenced
by an autorelease pool. This patch overcomes this behavior by loading a
weak object via call to objc_loadWeakRetained(), followng it by objc_release
at appropriate place, thereby removing the hidden autorelease. // rdar://10849570
llvm-svn: 168740
constructors.
When I first moved regparm support to TargetInfo.cpp I tried to isolate it
in classifyArgumentTypeWithReg, but it is actually a lot easier to flip the
code around and check for regparm at the end of the decision tree.
Without this refactoring classifyArgumentTypeWithReg would have to duplicate
the logic about when to use non-byval indirect arguments.
llvm-svn: 166266
Because PNaCl bitcode must be target-independent, it uses some
different bitcode representations from other targets (e.g. byval and
sret for structures). This means that without additional type
information, it cannot meet some native ABI requirements for some
targets (e.g. passing structures containing unions by value on
x86-64). To allow generation of code which uses the correct native
ABIs, we also support triples such as x86_64-nacl, which uses
target-dependent IR (as opposed to le32-nacl, which uses byval and
sret).
To allow interoperation between the two types of code, this patch adds
a calling convention attribute to be used in code compiled with the
target-dependent triple, which will generate code using the le32-style
bitcode. This calling convention does not need to be explicitly
supported in the backend because it determines bitcode representation
rather than native conventions (the backend just needs to undersand
how to handle byval and sret for the Native Client OS).
This patch implements __attribute__((pnaclcall)) to generate calls in
bitcode according to the le32 bitcode conventions, an attribute which
is accepted by any Native Client target, but issues a warning
otherwise.
llvm-svn: 166065
Convert the uses of the Attributes class over to the new format. The
Attributes::get method call now takes an LLVM context so that the attributes
object can be uniquified and stored.
llvm-svn: 165918
The issue arises when coercing to/from types of different sizes. We need
to be certain that the allocation on either end has sufficient room for
the coerced type. When it doesn't, we need to make room, copy across,
and then proceed. PR11905 handled the case of storing function arguments
back into allocas in the function prolog, this patch handles the case of
setting up the function arguments in a call expression.
This is actually significantly simpler than the fix for PR11905. It ends
up being a trivial change to create a temporary alloca when the source
is too small and memcpy across. This should preserve the compile-time
fast-isel benefits of doing gep+load sequences and avoiding FCAs.
Reviewed by Benjamin and Evgeniy (who fixed PR11905).
llvm-svn: 165615
objc_retainAutoreleasedReturnValue, we need to also be killing
them during return peepholing. Make sure we recognize an
intervening bitcast, but more importantly, assert if we can't
find the asm marker at all. rdar://problem/12133032
llvm-svn: 163431
attribute. It is a variation of the x86_64 ABI:
* A struct returned indirectly uses the first register argument to pass the
pointer.
* Floats, Doubles and structs containing only one of them are not passed in
registers.
* Other structs are split into registers if they fit on the remaining ones.
Otherwise they are passed in memory.
* When a struct doesn't fit it still consumes the registers.
llvm-svn: 161022
in the ABI arrangement, and leave a hook behind so that we can easily
tweak CCs on platforms that use different CCs by default for C++
instance methods.
llvm-svn: 159894
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.
This rolls back r155808 and r155869.
Review by Doug Gregor incorporating feedback from Chandler Carruth.
llvm-svn: 158104
filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.
This change errs on the side of value, making op-> return T* and op* return
T&.
(reviewed by Richard Smith)
llvm-svn: 155808
store to 1. This allows code-gen to select a more appropriate alignment. If left
to zero, an alignment greater than the alignment of the pointer may be selected,
causing code-gen to use instructions which require an alignment greater than the
pointer guarantees.
<rdar://problem/11043589>
llvm-svn: 152951
optional argument passed through the variadic ellipsis)
potentially affects how we need to lower it. Propagate
this information down to the various getFunctionInfo(...)
overloads on CodeGenTypes. Furthermore, rename those
overloads to clarify their distinct purposes, and make
sure we're calling the right one in the right place.
This has a nice side-effect of making it easier to construct
a function type, since the 'variadic' bit is no longer
separable.
This shouldn't really change anything for our existing
platforms, with one minor exception --- we should now call
variadic ObjC methods with the ... in the "right place"
(see the test case), which I guess matters for anyone
running GNUStep on MIPS. Mostly it's just a substantial
clean-up.
llvm-svn: 150788
-fno-objc-arc-exceptions. This will allow the optimizer to perform
optimizations which are only safe under that flag.
This is a part of rdar://10803830.
llvm-svn: 150644
This changes function prolog in such a way as to avoid out-of-bounds
stack store in the case when coerce-to type has a larger storage size
than the real argument type.
Fixes PR11905.
llvm-svn: 150238
is inserted before the real argument. Padding is needed to ensure the backend
reads from or writes to the correct argument slots when the original alignment
of a byval structure is unavailable due to flattening.
llvm-svn: 147699
Instead of always storing all source locations for the selector identifiers
we check whether all the identifiers are in a "standard" position; "standard" position is
-Immediately before the arguments: -(id)first:(int)x second:(int)y;
-With a space between the arguments: -(id)first: (int)x second: (int)y;
-For nullary selectors, immediately before ';': -(void)release;
In such cases we infer the locations instead of storing them.
llvm-svn: 140989
builtin types (When requested). This is another step toward making
ASTUnit build the ASTContext as needed when loading an AST file,
rather than doing so after the fact. No actual functionality change (yet).
llvm-svn: 138985
emit call results into potentially aliased slots. This allows us
to properly mark indirect return slots as noalias, at the cost
of requiring an extra memcpy when assigning an aggregate call
result into a l-value. It also brings us into compliance with
the x86-64 ABI.
llvm-svn: 138599
A homogeneous aggregate is an aggregate data structure where after flattening
any nesting there are 1 to 4 elements of the same base type that is either a
float, double, or Neon vector. All Neon vectors of the same size, either 64
or 128 bits, are treated as equivalent for this purpose. When using the
AAPCS-VFP ABI, check for homogeneous aggregates and pass them as arguments by
expanding them into a sequence of their base types. This requires extending
the existing support for expanded arguments to handle not only structs, but
also constant arrays and complex types.
llvm-svn: 136767
This is something of a hack, the problem is as follows:
1. we instantiate both copied of RetainPtr with the two different argument types
(an id and protocol-qualified id).
2. We refer to the ctor of one of the instantiations when introducing global "x",
this causes us to emit an llvm::Function for a prototype whose "this" has type
"RetainPtr<id<bork> >*".
3. We refer to the ctor of the other instantiation when introducing global "y",
however, because it *mangles to the same name as the other ctor* we just use
a bitcasted version of the llvm::Function we previously emitted.
4. We emit deferred declarations, causing us to emit the body of the ctor, however
the body we emit is for RetainPtr<id>, which expects its 'this' to have an IR
type of "RetainPtr<id>*".
Because of the mangling collision, we don't have this case, and explode.
This is really some sort of weird AST invariant violation or something, but hey
a bitcast makes the pain go away.
llvm-svn: 135572
to prevent recursive compilation problems. This fixes a failure of CodeGen/decl.c
on x86-32 targets that don't fill in the coerce-to type.
llvm-svn: 135256
types. Fore xample, we used to lower:
struct bar { int a; };
struct foo {
void (*FP)(struct bar);
} G;
to:
%struct.foo = type { {}* }
since the function pointer would cause recursive translation of bar and
we didn't know if that would get us into trouble. We are now smart enough
to know that it is fine, so we get this type instead:
%struct.foo = type { void (i32)* }
Codegen still needs to be prepared for uncooperative types at any place,
which is why I let the maximally uncooperative code sit around for awhile to
help shake out the bugs.
llvm-svn: 135244
Reid Kleckner