This is just the clang-side of 32-bit SEH. LLVM still needs work, and it
will determinstically fail to compile until it's feature complete.
On x86, all outlined handlers have no parameters, but they do implicitly
take the EBP value passed in and use it to address locals of the parent
frame. We model this with llvm.frameaddress(1).
This works (mostly), but __finally block inlining can break it. For now,
we apply the 'noinline' attribute. If we really want to inline __finally
blocks on 32-bit x86, we should teach the inliner how to untangle
frameescape and framerecover.
Promote the error diagnostic from codegen to sema. It now rejects SEH on
non-Windows platforms. LLVM doesn't implement SEH on non-x86 Windows
platforms, but there's nothing preventing it.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236052 91177308-0d34-0410-b5e6-96231b3b80d8
The RegionCounter type does a lot of legwork, but most of it is only
meaningful within the implementation of CodeGenPGO. The uses elsewhere
in CodeGen generally just want to increment or read counters, so do
that directly.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235664 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r234700. It turns out that the lifetime markers
were not the cause of Chromium failing but a bug which was uncovered by
optimizations exposed by the markers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235553 91177308-0d34-0410-b5e6-96231b3b80d8
The frameescape intrinsic cannot be inlined, so I fixed the inliner in
r234937. This should address PR23216.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234942 91177308-0d34-0410-b5e6-96231b3b80d8
Even though these symbols are in a comdat group, the Microsoft linker
really wants them to have internal linkage.
I'm planning to tweak the mangling in a follow-up change. This is a
straight revert with a 1-line fix.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234613 91177308-0d34-0410-b5e6-96231b3b80d8
Now that TailRecursionElimination has been fixed with r222354, the
threshold on size for lifetime marker insertion can be removed. This
only affects named temporary though, as the patch for unnamed temporaries
is still in progress.
My previous commit (r222993) was not handling debuginfo correctly, but
this could only be seen with some asan tests. Basically, lifetime markers
are just instrumentation for the compiler's usage and should not affect
debug information; however, the cleanup infrastructure was assuming it
contained only destructors, i.e. actual code to be executed, and was
setting the breakpoint for the end of the function to the closing '}', and
not the return statement, in order to show some destructors have been
called when leaving the function. This is wrong when the cleanups are only
lifetime markers, and this is now fixed.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234581 91177308-0d34-0410-b5e6-96231b3b80d8
WinEHPrepare was going to have to pattern match the control flow merge
and split that the old lowering used, and that wasn't really feasible.
Now we can teach WinEHPrepare to pattern match this, which is much
simpler:
%fp = call i8* @llvm.frameaddress(i32 0)
call void @func(iN [01], i8* %fp)
This prototype happens to match the prototype used by the Win64 SEH
personality function, so this is really simple.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234532 91177308-0d34-0410-b5e6-96231b3b80d8
The driver currently accepts but ignores the -freciprocal-math flag.
This patch passes the flag through and enables 'arcp' fast-math-flag
generation in IR.
Note that this change does not actually enable the optimization for
any target. The reassociation optimization that this flag specifies
was implemented by http://reviews.llvm.org/D6334 :
http://llvm.org/viewvc/llvm-project?view=revision&revision=222510
Because the optimization is done in the backend rather than IR,
the backend must be modified to understand instruction-level
fast-math-flags or a new function-level attribute must be created.
Also note that -freciprocal-math is independent of any target-specific
usage of reciprocal estimate hardware instructions. That requires
its own flag ('-mrecip').
https://llvm.org/bugs/show_bug.cgi?id=20912
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234493 91177308-0d34-0410-b5e6-96231b3b80d8
The test should be fixed. It was failing in NDEBUG builds due to a
missing '*' character in a regex. In asserts builds, the pattern matched
a single digit value, which became a double digit value in NDEBUG
builds. Go figure.
This reverts commit r234261.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234447 91177308-0d34-0410-b5e6-96231b3b80d8
While capturing filters aren't very common, we'd like to outline
__finally blocks in the frontend to simplify -O0 EH preparation and
reduce code size. Finally blocks are usually have captures, and this is
the first step towards that.
Currently we don't support capturing 'this' or VLAs.
Reviewers: majnemer
Differential Revision: http://reviews.llvm.org/D8825
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234261 91177308-0d34-0410-b5e6-96231b3b80d8
Looks like the VTable code in particular will need some work to pass
around the pointee type explicitly.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@234128 91177308-0d34-0410-b5e6-96231b3b80d8
There are no widely deployed standard libraries providing sized
deallocation functions, so we have to punt and ask the user if they want
us to use sized deallocation. In the future, when such libraries are
deployed, we can teach the driver to detect them and enable this
feature.
N3536 claimed that a weak thunk from sized to unsized deallocation could
be emitted to avoid breaking backwards compatibility with standard
libraries not providing sized deallocation. However, this approach and
other variations don't work in practice.
With the weak function approach, the thunk has to have default
visibility in order to ensure that it is overridden by other DSOs
providing sized deallocation. Weak, default visibility symbols are
particularly expensive on MachO, so John McCall was considering
disabling this feature by default on Darwin. It also changes behavior
ELF linking behavior, causing certain otherwise unreferenced object
files from an archive to be pulled into the link.
Our second approach was to use an extern_weak function declaration and
do an inline conditional branch at the deletion call site. This doesn't
work because extern_weak only works on MachO if you have some archive
providing the default value of the extern_weak symbol. Arranging to
provide such an archive has the same challenges as providing the symbol
in the standard library. Not to mention that extern_weak doesn't really
work on COFF.
Reviewers: rsmith, rjmccall
Differential Revision: http://reviews.llvm.org/D8467
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@232788 91177308-0d34-0410-b5e6-96231b3b80d8
The current implementation causes link-time ODR violations when the delete symbols are exported into the dynamic table.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@229241 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM doesn't support non-call exceptions, so inlining makes it harder to
catch such asynchronous exceptions.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@228876 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we would simply double-emit the body of the __finally block,
but that doesn't work when it contains any kind of Decl, which we can't
double emit.
This fixes that by emitting the block once and branching into a shared
code region and then branching back out.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@228222 91177308-0d34-0410-b5e6-96231b3b80d8
Now if you break on a dtor and go 'up' in your debugger (or you get an
asan failure in a dtor) during an exception unwind, you'll have more
context. Instead of all dtors appearing to be called from the '}' of the
function, they'll be attributed to the end of the scope of the variable,
the same as the non-exceptional dtor call.
This doesn't /quite/ remove all uses of CurEHLocation (which might be
nice to remove, for a few reasons) - it's still used to choose the
location for some other work in the landing pad. It'd be nice to
attribute that code to the same location as the exception calls within
the block and to remove CurEHLocation.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@228181 91177308-0d34-0410-b5e6-96231b3b80d8
This is half a fix for a GDB test suite failure that expects to start at
'a' in the following code:
void func(int a)
if (a
&&
b)
...
But instead, without this change, the comparison was assigned to '&&'
(well, worse actually - because there was a chained 'a && b && c' and it
was assigned to the second '&&' because of a recursive application of
this bug) and then the load folded into the comparison so breaking on
the function started at '&&' instead of 'a'.
The other part of this needs to be fixed in LLVM where it's ignoring the
location of the icmp and instead using the location of the branch
instruction.
The fix to the conditional operator is actually a no-op currently,
because the conditional operator's location coincides with 'a' (the
start of the conditional expression) but should probably be '?' instead.
See the FIXME in the test case that mentions the ARCMigration tool
failures when I tried to make that change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@227356 91177308-0d34-0410-b5e6-96231b3b80d8
The lowering looks a lot like normal EH lowering, with the exception
that the exceptions are caught by executing filter expression code
instead of matching typeinfo globals. The filter expressions are
outlined into functions which are used in landingpad clauses where
typeinfo would normally go.
Major aspects that still need work:
- Non-call exceptions in __try bodies won't work yet. The plan is to
outline the __try block in the frontend to keep things simple.
- Filter expressions cannot use local variables until capturing is
implemented.
- __finally blocks will not run after exceptions. Fixing this requires
work in the LLVM SEH preparation pass.
The IR lowering looks like this:
// C code:
bool safe_div(int n, int d, int *r) {
__try {
*r = normal_div(n, d);
} __except(_exception_code() == EXCEPTION_INT_DIVIDE_BY_ZERO) {
return false;
}
return true;
}
; LLVM IR:
define i32 @filter(i8* %e, i8* %fp) {
%ehptrs = bitcast i8* %e to i32**
%ehrec = load i32** %ehptrs
%code = load i32* %ehrec
%matches = icmp eq i32 %code, i32 u0xC0000094
%matches.i32 = zext i1 %matches to i32
ret i32 %matches.i32
}
define i1 zeroext @safe_div(i32 %n, i32 %d, i32* %r) {
%rr = invoke i32 @normal_div(i32 %n, i32 %d)
to label %normal unwind to label %lpad
normal:
store i32 %rr, i32* %r
ret i1 1
lpad:
%ehvals = landingpad {i8*, i32} personality i32 (...)* @__C_specific_handler
catch i8* bitcast (i32 (i8*, i8*)* @filter to i8*)
%ehptr = extractvalue {i8*, i32} %ehvals, i32 0
%sel = extractvalue {i8*, i32} %ehvals, i32 1
%filter_sel = call i32 @llvm.eh.seh.typeid.for(i8* bitcast (i32 (i8*, i8*)* @filter to i8*))
%matches = icmp eq i32 %sel, %filter_sel
br i1 %matches, label %eh.except, label %eh.resume
eh.except:
ret i1 false
eh.resume:
resume
}
Reviewers: rjmccall, rsmith, majnemer
Differential Revision: http://reviews.llvm.org/D5607
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226760 91177308-0d34-0410-b5e6-96231b3b80d8
Several pieces of code were relying on implicit debug location setting
which usually lead to incorrect line information anyway. So I've fixed
those (in r225955 and r225845) separately which should pave the way for
this commit to be cleanly reapplied.
The reason these implicit dependencies resulted in crashes with this
patch is that the debug location would no longer implicitly leak from
one place to another, but be set back to invalid. Once a call with
no/invalid location was emitted, if that call was ever inlined it could
produce invalid debugloc chains and assert during LLVM's codegen.
There may be further cases of such bugs in this patch - they're hard to
flush out with regression testing, so I'll keep an eye out for reports
and investigate/fix them ASAP if they come up.
Original commit message:
Reapply "DebugInfo: Generalize debug info location handling"
Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).
Recommitted in r224941 and reverted in r224970 after it caused a crash
when building compiler-rt. Looks to be due to this change zeroing out
the debug location when emitting default arguments (which were meant to
inherit their outer expression's location) thus creating call
instructions without locations - these create problems for inlining and
must not be created. That is fixed and tested in this version of the
change.
Original commit message:
This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.
This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.
I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.
Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.
I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@225956 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r225000, r225021, r225083, r225086, r225090.
The root change (r225000) still has several issues where it's caused
calls to be emitted without debug locations. This causes assertion
failures if/when those calls are inlined.
I'll work up some test cases and fixes before recommitting this.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@225555 91177308-0d34-0410-b5e6-96231b3b80d8
arithmetic relaxation flags:
-cl-no-signed-zeros
-cl-unsafe-math-optimizations
-cl-finite-math-only
-cl-fast-relaxed-math
Propagate the info to FP instruction flags as well
as function attributes where they are available.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223928 91177308-0d34-0410-b5e6-96231b3b80d8
The logic for lowering profiling counters has been moved to an LLVM
pass. Emit the intrinsics rather than duplicating the whole pass in
clang.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223683 91177308-0d34-0410-b5e6-96231b3b80d8
http://llvm.org/bugs/show_bug.cgi?id=21555
Currently, kernel argument metadata is omitted unless the
"-cl-kernel-arg-info" option is specified. But the SPIR 1.2 spec
requires that all metadata except kernel_arg_name should always be
emitted, and kernel_arg_name is only emitted when
"-cl-kernel-arg-info" is specified.
Patch ported by Ryan Burn from the Khronos SPIR generator.
https://github.com/KhronosGroup/SPIR
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223340 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change makes CodeGenFunction::EmitCheck() take several
conditions that needs to be checked (all of them need to be true),
together with sanitizer kinds these checks are for. This would allow
to split one call into UBSan runtime into several calls in case
different sanitizer kinds would have different recoverability
settings.
Tests should be fixed accordingly, I'm working on it.
Test Plan: regression test suite.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D6219
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221716 91177308-0d34-0410-b5e6-96231b3b80d8
Make sure CodeGenFunction::EmitCheck() knows which sanitizer
it emits check for. Make CheckRecoverableKind enum an
implementation detail and move it away from header.
Currently CheckRecoverableKind is determined by the type of
sanitizer ("unreachable" and "return" are unrecoverable,
"vptr" is always-recoverable, all the rest are recoverable).
This will change in future if we allow to specify which sanitizers
are recoverable, and which are not by -fsanitize-recover= flag.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221635 91177308-0d34-0410-b5e6-96231b3b80d8
Use the bitmask to store the set of enabled sanitizers instead of a
bitfield. On the negative side, it makes syntax for querying the
set of enabled sanitizers a bit more clunky. On the positive side, we
will be able to use SanitizerKind to eventually implement the
new semantics for -fsanitize-recover= flag, that would allow us
to make some sanitizers recoverable, and some non-recoverable.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221558 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The Itanium ABI approach of using offset-to-top isn't possible with the
MS ABI, it doesn't have that kind of information lying around.
Instead, we do the following:
- Call the virtual deleting destructor with the "don't delete the object
flag" set. The virtual deleting destructor will return a pointer to
'this' adjusted to the most derived class.
- Call the global delete using the adjusted 'this' pointer.
Reviewers: rnk
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D5996
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220993 91177308-0d34-0410-b5e6-96231b3b80d8
SanitizerOptions is not even a POD now, so having global variable of
this type, is not nice. Instead, provide a regular constructor and clear()
method, and let each CodeGenFunction has its own copy of SanitizerOptions
it uses.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220920 91177308-0d34-0410-b5e6-96231b3b80d8
This commit changes the way we blacklist functions in ASan, TSan,
MSan and UBSan. We used to treat function as "blacklisted"
and turned off instrumentation in it in two cases:
1) Function is explicitly blacklisted by its mangled name.
This part is not changed.
2) Function is located in llvm::Module, whose identifier is
contained in the list of blacklisted sources. This is completely
wrong, as llvm::Module may not correspond to the actual source
file function is defined in. Also, function can be defined in
a header, in which case user had to blacklist the .cpp file
this header was #include'd into, not the header itself.
Such functions could cause other problems - for instance, if the
header was included in multiple source files, compiled
separately and linked into a single executable, we could end up
with both instrumented and non-instrumented version of the same
function participating in the same link.
After this change we will make blacklisting decision based on
the SourceLocation of a function definition. If a function is
not explicitly defined in the source file, (for example, the
function is compiler-generated and responsible for
initialization/destruction of a global variable), then it will
be blacklisted if the corresponding global variable is defined
in blacklisted source file, and will be instrumented otherwise.
After this commit, the active users of blacklist files may have
to revisit them. This is a backwards-incompatible change, but
I don't think it's possible or makes sense to support the
old incorrect behavior.
I plan to make similar change for blacklisting GlobalVariables
(which is ASan-specific).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219997 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGenFunction objects aren't really designed to be reused for more
than one function, and doing so can leak debug info location information
from one function into the prologue of the next.
Add an assertion in to catch reuses of CodeGenFunction, which
surprisingly only caught the ObjC atomic getter/setter cases. Fix those
and add a test to demonstrate the issue.
The test is a bit slim, because we're just testing for the absence of a
debug location on the prologue instructions, which by itself probably
wouldn't be the end of the world - but the particular debug location
that was ending up there was for the previous function's last
instruction. This produced debug info for another function within this
function, which is something I'm trying to remove all cases of as its a
substantial source of bugs, especially around inlining (see r219215).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219690 91177308-0d34-0410-b5e6-96231b3b80d8
This will give more information to the optimizers so that they can reuse stack slots
and reduce stack usage.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218865 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen would try to come up with an LLVM IR type for a pointer to
member type on the way to forming an LLVM IR type for a pointer to
pointer to member type.
However, if the pointer to member representation has not been locked in yet,
we would not be able to come up with a pointer to member IR type.
In these cases, make the pointer to member type an incomplete type.
This will make the pointer to pointer to member type a pointer to an
incomplete type. If the class eventually obtains an inheritance model,
we will make the pointer to member type represent the actual inheritance
model.
Differential Revision: http://reviews.llvm.org/D5373
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@218084 91177308-0d34-0410-b5e6-96231b3b80d8
If control falls off the end of a function after an __asm block, MSVC
assumes that the inline assembly filled the EAX and possibly EDX
registers with an appropriate return value. This functionality is used
in inline functions returning 64-bit integers in system headers, so we
need some amount of compatibility.
This is implemented in Clang by adding extra output constraints to every
inline asm block, and storing the resulting output registers into the
return value slot. If we see an asm block somewhere in the function
body, we emit a normal epilogue instead of marking the end of the
function with a return type unreachable.
Normal returns in functions not using this functionality will overwrite
the return value slot, and in most cases LLVM should be able to
eliminate the dead stores.
Fixes PR17201.
Reviewed By: majnemer
Differential Revision: http://reviews.llvm.org/D5177
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@217187 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
PR19838
When operator new[] is called and an array cookie is created
we want asan to detect buffer overflow bugs that touch the cookie.
For that we need to
a) poison the shadow for the array cookie (call __asan_poison_cxx_array_cookie).
b) ignore the legal accesses to the cookie generated by clang (add 'nosanitize' metadata)
Reviewers: timurrrr, samsonov, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4774
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216434 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the '-fcoverage-mapping' option which
allows clang to generate the coverage mapping information
that can be used to provide code coverage analysis using
the execution counts obtained from the instrumentation
based profiling (-fprofile-instr-generate).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214752 91177308-0d34-0410-b5e6-96231b3b80d8
As defined in the SPIR 1.2 specification, this node behaves similarly to
kernel_arg_type but will print the underlying type name, e.g., without
typedefs.
Example:
typedef unsigned int myunsignedint;
would report:
'myunsignedint' in the kernel_arg_type node
'uint' in the kernel_arg_base_type node
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214308 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a bug where kernel_arg_type was always changing 'unsigned ' to 'u'
for any parameter type, including non-canonical types.
Example:
typedef unsigned int myunsignedint;
would report:
"myunt"
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214305 91177308-0d34-0410-b5e6-96231b3b80d8
The target method of the thunk will perform the cleanup. This can't be
tested in 32-bit x86 yet because passing something by value would create
an inalloca, and we refuse to generate broken code for that.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213976 91177308-0d34-0410-b5e6-96231b3b80d8
This is used to mark the instructions emitted by Clang to implement
variety of UBSan checks. Generally, we don't want to instrument these
instructions with another sanitizers (like ASan).
Reviewed in http://reviews.llvm.org/D4544
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213291 91177308-0d34-0410-b5e6-96231b3b80d8
Now CodeGenFunction is responsible for looking at sanitizer blacklist
(in CodeGenFunction::StartFunction) and turning off instrumentation,
if necessary.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212501 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
MSVC always passes 'sret' after 'this', unlike GCC. This required
changing a number of places in Clang that assumed the sret parameter was
always first in LLVM IR.
This fixes win64 MSVC ABI compatibility for methods returning structs.
Reviewers: rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D3618
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@208458 91177308-0d34-0410-b5e6-96231b3b80d8
and no return expr at the end of the function.
The "function has only simple returns" check in FinishFunction tests
whether the number of simple return exprs equals the number of return
exprs, but so far a fallthrough at the end of a function was not counted
as a return, which would result in cleanup code being associated with the
wrong source line.
rdar://problem/16733984.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207480 91177308-0d34-0410-b5e6-96231b3b80d8
are not associated with any source lines.
Previously, if the Location of a Decl was empty, EmitFunctionStart would
just keep using CurLoc, which would sometimes be correct (e.g., thunks)
but in other cases would just point to a hilariously random location.
This patch fixes this by completely eliminating all uses of CurLoc from
EmitFunctionStart and rather have clients explicitly pass in a
SourceLocation for the function header and the function body.
rdar://problem/14985269
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@205999 91177308-0d34-0410-b5e6-96231b3b80d8
These flags are deprecated since at least Clang 3.3. Users should instead
use -fsanitize= with appropriate values.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204330 91177308-0d34-0410-b5e6-96231b3b80d8
In instrumentation-based profiling, we need a set of data structures to
represent the counters. Previously, these were built up during static
initialization. Now, they're shoved into a specially-named section so
that they show up as an array.
As a consequence of the reorganizing symbols, instrumentation data
structures for linkonce functions are now correctly coalesced.
This is the first step in a larger project to minimize runtime overhead
and dependencies in instrumentation-based profilng. The larger picture
includes removing all initialization overhead and making the dependency
on libc optional.
<rdar://problem/15943240>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204080 91177308-0d34-0410-b5e6-96231b3b80d8
r203364: what was use_iterator is now user_iterator, and there is
a use_iterator for directly iterating over the uses.
This also switches to use the range-based APIs where appropriate.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203365 91177308-0d34-0410-b5e6-96231b3b80d8
In addition, for all functions, use the name from the llvm::Function to
identify the function in the profile data. Compute that "function name",
including the file name for local functions, once when assigning the PGO
counters and store it in the CodeGenPGO class.
Move the code to add InlineHint and Cold attributes out of StartFunction(),
because the "function name" string isn't available at that point.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203075 91177308-0d34-0410-b5e6-96231b3b80d8
Move the PGO.assignRegionCounters() call out of StartFunction, because that
function is called from many places where it does not make sense to do PGO
instrumentation (e.g., compiler-generated helper functions). Change several
functions to take a StringRef argument for the unique name associated with
a function, so that the name can be set differently for things like Objective-C
methods and block literals.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@203073 91177308-0d34-0410-b5e6-96231b3b80d8
The __forceinline keyword's semantics are now recast as AlwaysInline and
the kw___forceinline token has its language mode set for KEYMS.
This preserves the semantics of the previous implementation but with
less duplication of code.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202131 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, we made one traversal of the AST prior to codegen to assign
counters to the ASTs and then propagated the count values during codegen. This
patch now adds a separate AST traversal prior to codegen for the
-fprofile-instr-use option to propagate the count values. The counts are then
saved in a map from which they can be retrieved during codegen.
This new approach has several advantages:
1. It gets rid of a lot of extra PGO-related code that had previously been
added to codegen.
2. It fixes a serious bug. My original implementation (which was mailed to the
list but never committed) used 3 counters for every loop. Justin improved it to
move 2 of those counters into the less-frequently executed breaks and continues,
but that turned out to produce wrong count values in some cases. The solution
requires visiting a loop body before the condition so that the count for the
condition properly includes the break and continue counts. Changing codegen to
visit a loop body first would be a fairly invasive change, but with a separate
AST traversal, it is easy to control the order of traversal. I've added a
testcase (provided by Justin) to make sure this works correctly.
3. It improves the instrumentation overhead, reducing the number of counters for
a loop from 3 to 1. We no longer need dedicated counters for breaks and
continues, since we can just use the propagated count values when visiting
breaks and continues.
To make this work, I needed to make a change to the way we count case
statements, going back to my original approach of not including the fall-through
in the counter values. This was necessary because there isn't always an AST node
that can be used to record the fall-through count. Now case statements are
handled the same as default statements, with the fall-through paths branching
over the counter increments. While I was at it, I also went back to using this
approach for do-loops -- omitting the fall-through count into the loop body
simplifies some of the calculations and make them behave the same as other
loops. Whenever we start using this instrumentation for coverage, we'll need
to add the fall-through counts into the counter values.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201528 91177308-0d34-0410-b5e6-96231b3b80d8
We collect a maximal function count among all functions in the pgo data file.
For functions that are hot, we set its InlineHint attribute. For functions that
are cold, we set its Cold attribute.
We currently treat functions with >= 30% of the maximal function count as hot
and functions with <= 1% of the maximal function count are treated as cold.
These two numbers are from preliminary tuning on SPEC.
This commit should not affect non-PGO builds and should boost performance on
instrumentation based PGO.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200874 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200597 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200082 91177308-0d34-0410-b5e6-96231b3b80d8
marked as AlwaysInline or ForceInline.
This moves us to what gcc does with -fno-inline. The attribute approach
was discussed to be better than switching to InlineAlways inliner in presence
of LTO.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199324 91177308-0d34-0410-b5e6-96231b3b80d8
adjustFallThroughCount isn't a good name, and the documentation was
even worse. This commit attempts to clarify what it's for and when to
use it.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199139 91177308-0d34-0410-b5e6-96231b3b80d8
from the global address space (6.5.1 of the OpenCL 1.2 specification).
This makes clang construct the image arguments in the global address
space and generate the argument metadata with the correct address space
descriptor.
Patch by Pedro Ferreira!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198868 91177308-0d34-0410-b5e6-96231b3b80d8
C and C++ don't emit an extra lexical scope for the compound statement
that is the body of an Objective-C method.
rdar://problem/15010825
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198699 91177308-0d34-0410-b5e6-96231b3b80d8
the lexical block formed by the compound statement that is the function
body.
rdar://problem/15010825
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198461 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197518 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In general, this type node can be used to represent any type adjustment
that occurs implicitly without losing type sugar. The immediate use of
this is to adjust the calling conventions of member function pointer
types without breaking template instantiation.
Fixes PR17996.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D2332
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@196451 91177308-0d34-0410-b5e6-96231b3b80d8
deallocation function (and the corresponding unsized deallocation function has
been declared), emit a weak discardable definition of the function that
forwards to the corresponding unsized deallocation.
This allows a C++ standard library implementation to provide both a sized and
an unsized deallocation function, where the unsized one does not just call the
sized one, for instance by putting both in the same object file within an
archive.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194055 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193717 91177308-0d34-0410-b5e6-96231b3b80d8
Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- generic lambdas within template functions and nested
within other generic lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
(Although I have gotten some useful feedback on my patches of the above and will be incorporating that as I submit those patches for commit)
As an example of what compiles through this commit:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
This patch has been reviewed by Doug and Richard. Minor changes (non-functionality affecting) have been made since both of them formally looked at it, but the changes involve removal of supernumerary return type deduction changes (since they are now redundant, with richard having committed a recent patch to address return type deduction for C++11 lambdas using C++14 semantics).
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that SemaType.cpp::ConvertDeclSpecToType may use it to immediately
generate a template-parameter-type when 'auto' is parsed in a generic
lambda parameter context. (i.e we do NOT use AutoType deduced to
a template parameter type - Richard seemed ok with this approach).
We encode that this template type was generated from an auto by simply
adding $auto to the name which can be used for better diagnostics if needed.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- various tests were added - but much more will be needed.
There is obviously more work to be done, and both Richard (weakly) and Doug (strongly)
have requested that LambdaExpr be removed form the CXXRecordDecl LambdaDefinitionaData
in a future patch which is forthcoming.
A greatful thanks to all reviewers including Eli Friedman, James Dennett,
and especially the two gracious wizards (Richard Smith and Doug Gregor)
who spent hours providing feedback (in person in Chicago and on the mailing lists).
And yet I am certain that I have allowed unidentified bugs to creep in; bugs, that I will do my best to slay, once identified!
Thanks!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191453 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGenFunction is run on only one function - a new object is made for
each new function. I would add an assertion/flag to this effect, but
there's an exception: ObjC properties involve emitting helper functions
that are all emitted by the same CodeGenFunction object, so such a check
is not possible/correct.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189277 91177308-0d34-0410-b5e6-96231b3b80d8
Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- nested lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
As an example of what compiles:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Augment AutoType's constructor (similar to how variadic
template-type-parameters ala TemplateTypeParmDecl are implemented) to
accept an IsParameterPack to encode a generic lambda parameter pack.
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that Sema::ActOnLambdaAutoParameter may use it to create the
appropriate list of corresponding TemplateTypeParmDecl for each
auto parameter identified within the generic lambda (also stored
within the current LambdaScopeInfo). Additionally,
a TemplateParameterList data-member was added to hold the invented
TemplateParameterList AST node which will be much more useful
once we teach TreeTransform how to transform generic lambdas.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- Teach Sema::ActOnStartOfLambdaDefinition to set the
return type of a lambda without a trailing return type
to 'auto' in C++1y mode, and teach the return type
deduction machinery in SemaStmt.cpp to process either
C++11 and C++14 lambda's correctly depending on the flag.
- various tests were added - but much more will be needed.
A greatful thanks to all reviewers including Eli Friedman,
James Dennett and the ever illuminating Richard Smith. And
yet I am certain that I have allowed unidentified bugs to creep in;
bugs, that I will do my best to slay, once identified!
Thanks!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188977 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor the underlying code a bit to remove unnecessary calls to
"hasErrorOccurred" & make them consistently at all the entry points to
the IRGen ASTConsumer.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188707 91177308-0d34-0410-b5e6-96231b3b80d8
only affect functions without a separate return block. This fixes the
linetable for void functions with cleanups and multiple returns.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187090 91177308-0d34-0410-b5e6-96231b3b80d8
Test coverage for non-dependent pack expansions doesn't demonstrate a
failure prior to this patch (a follow-up commit improving debug info
will cover this commit specifically) but covers a related hole in our
test coverage.
Reviewed by Richard Smith & Eli Friedman.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186261 91177308-0d34-0410-b5e6-96231b3b80d8
This allows clang to use the backend parameter attribute 'returned' when generating 'this'-returning constructors and destructors in ARM and MSVC C++ ABIs.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185291 91177308-0d34-0410-b5e6-96231b3b80d8
The goal of this sugar node is to be able to look at an arbitrary
FunctionType and tell if any of the parameters were decayed from an
array or function type. Ultimately this is necessary to implement
Microsoft's C++ name mangling scheme, which mangles decayed arrays
differently from normal pointers.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1014
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184763 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184205 91177308-0d34-0410-b5e6-96231b3b80d8
were lacking ExprWithCleanups nodes in some cases where the new approach to
lifetime extension needed them).
Original commit message:
Rework IR emission for lifetime-extended temporaries. Instead of trying to walk
into the expression and dig out a single lifetime-extended entity and manually
pull its cleanup outside the expression, instead keep a list of the cleanups
which we'll need to emit when we get to the end of the full-expression. Also
emit those cleanups early, as EH-only cleanups, to cover the case that the
full-expression does not terminate normally. This allows IR generation to
properly model temporary lifetime when multiple temporaries are extended by the
same declaration.
We have a pre-existing bug where an exception thrown from a temporary's
destructor does not clean up lifetime-extended temporaries created in the same
expression and extended to automatic storage duration; that is not fixed by
this patch.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183859 91177308-0d34-0410-b5e6-96231b3b80d8
EmitCapturedStmt creates a captured struct containing all of the captured
variables, and then emits a call to the outlined function. This is similar in
principle to EmitBlockLiteral.
GenerateCapturedFunction actually produces the outlined function. It is based
on GenerateBlockFunction, but is much simpler. The function type is determined
by the parameters that are in the CapturedDecl.
Some changes have been added to this patch that were reviewed as part of the
serialization patch and moving the parameters to the captured decl.
Differential Revision: http://llvm-reviews.chandlerc.com/D640
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181536 91177308-0d34-0410-b5e6-96231b3b80d8
Un-break the gdb buildbot.
- Use the debug location of the return expression for the cleanup code
if the return expression is trivially evaluatable, regardless of the
number of stop points in the function.
- Ensure that any EH code in the cleanup still gets the line number of
the closing } of the lexical scope.
- Added a testcase with EH in the cleanup.
rdar://problem/13442648
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181056 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181000 91177308-0d34-0410-b5e6-96231b3b80d8
- Use the debug location of the return expression for the cleanup code
if the return expression is trivially evaluatable, regardless of the
number of stop points in the function.
- Ensure that any EH code in the cleanup still gets the line number of
the closing } of the lexical scope.
- Added a testcase with EH in the cleanup.
rdar://problem/13442648
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180982 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180932 91177308-0d34-0410-b5e6-96231b3b80d8
are now two distinct canonical 'AutoType's: one is the undeduced 'auto'
placeholder type, and the other is a deduced-but-dependent type. All
deduced-to-a-non-dependent-type cases are still non-canonical.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180789 91177308-0d34-0410-b5e6-96231b3b80d8
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179958 91177308-0d34-0410-b5e6-96231b3b80d8
Initialize CalleeWithThisReturn to 0 in the constructor.
Also revert r170815 since checking CalleeWithThisReturn is faster.
PR15598
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178053 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177541 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177211 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176656 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176286 91177308-0d34-0410-b5e6-96231b3b80d8
Reid Kleckner