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.
llvm-svn: 225956
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.
llvm-svn: 225555
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.
llvm-svn: 225000
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).
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.
llvm-svn: 224941
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.
llvm-svn: 224385
This actually came up as a break in UBSan tests (look for a follow-up
commit to this one to see the UBSan test fallout) when I tried a broader
fix to location information.
I have some other ideas about how to do that broader change & will keep
looking into it.
llvm-svn: 224221
The extension has the following syntax:
__builtin_call_with_static_chain(Call, Chain)
where Call must be a function call expression and Chain must be of pointer type
This extension performs a function call Call with a static chain pointer
Chain passed to the callee in a designated register. This is useful for
calling foreign language functions whose ABI uses static chain pointers
(e.g. to implement closures).
Differential Revision: http://reviews.llvm.org/D6332
llvm-svn: 224167
Consider this program:
struct A {
virtual void operator-() { printf("base\n"); }
};
struct B final : public A {
virtual void operator-() override { printf("derived\n"); }
};
int main() {
B* b = new B;
-static_cast<A&>(*b);
}
Before this patch, clang saw the virtual call to A::operator-(), figured out
that it can be devirtualized, and then just called A::operator-() directly,
without going through the vtable. Instead, it should've looked up which
operator-() the call devirtualizes to and should've called that.
For regular virtual member calls, clang gets all this right already. So
instead of giving EmitCXXOperatorMemberCallee() all the logic that
EmitCXXMemberCallExpr() already has, cut the latter function into two pieces,
call the second piece EmitCXXMemberOrOperatorMemberCallExpr(), and use it also
to generate code for calls to virtual member operators.
This way, virtual overloaded operators automatically don't get devirtualized
if they have covariant returns (like it was done for regular calls in r218602),
etc.
This also happens to fix (or at least improve) codegen for explicit constructor
calls (`A a; a.A::A()`) in MS mode with -fsanitize-address-field-padding=1.
(This adjustment for virtual operator calls seems still wrong with the MS ABI.)
llvm-svn: 223185
Summary: If we've added poisoned paddings to a type do not emit memcpy for operator=.
Test Plan: regression tests.
Reviewers: majnemer, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D6160
llvm-svn: 221739
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
llvm-svn: 220993
Fixes incorrect codegen when devirtualization is aborted due to covariant return types.
Differential Revision: http://reviews.llvm.org/D5321
llvm-svn: 218602
Summary:
This patch implements a new UBSan check, which verifies
that function arguments declared to be nonnull with __attribute__((nonnull))
are actually nonnull in runtime.
To implement this check, we pass FunctionDecl to CodeGenFunction::EmitCallArgs
(where applicable) and if function declaration has nonnull attribute specified
for a certain formal parameter, we compare the corresponding RValue to null as
soon as it's calculated.
Test Plan: regression test suite
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, rnk
Differential Revision: http://reviews.llvm.org/D5082
llvm-svn: 217389
There were code paths that are duplicated for constructors and destructors just
because we have both CXXCtorType and CXXDtorsTypes.
This patch introduces an unified enum and reduces code deplication a bit.
llvm-svn: 217383
into EmitCXXMemberOrOperatorCall methods. In the end we want
to make declaration visible in EmitCallArgs() method, that
would allow us to alter CodeGen depending on function/parameter
attributes.
No functionality change.
llvm-svn: 216404
Summary:
This is a first small step towards passing generic "Expr" instead of
ArgBeg/ArgEnd pair into EmitCallArgs() family of methods. Having "Expr" will
allow us to get the corresponding FunctionDecl and its ParmVarDecls,
thus allowing us to alter CodeGen depending on the function/parameter
attributes.
No functionality change.
Test Plan: regression test suite
Reviewers: rnk
Reviewed By: rnk
Subscribers: aemerson, cfe-commits
Differential Revision: http://reviews.llvm.org/D4915
llvm-svn: 216214
Thoroughly check for a pointer dereference which yields a glvalue. Look
through casts, comma operators, conditional operators, paren
expressions, etc.
This was originally D4416.
Differential Revision: http://reviews.llvm.org/D4592
llvm-svn: 213434
This reverts commit r213401, r213402, r213403, and r213404.
I accidently committed these changes instead of updating the
differential.
llvm-svn: 213405
Summary:
Thoroughly check for a pointer dereference which yields a glvalue. Look
through casts, comma operators, conditional operators, paren
expressions, etc.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4416
llvm-svn: 213401
This reverts commit r211467 which reverted r211408,r211410, it caused
crashes in test/SemaCXX/undefined-internal.cpp for i686-win32 targets.
llvm-svn: 211473
This refactors the emission of dynamic_cast and typeid expressions so
that ABI specific knowledge lives in appropriate places. There are
quite a few benefits for having the two implementations share a common
core like sharing logic for optimization opportunities.
While we are at it, clean up the tests.
llvm-svn: 211402
This patch implements call lower from dynamic_cast to __RTDynamicCast
and __RTCastToVoid. Test cases are included. A feature of note is that
helper function getPolymorphicOffset is placed in such a way that it can
be used by EmitTypeid (to be implemented in a later patch) without being
moved. Details are included as comments directly in the code.
llvm-svn: 210377
to the normal non-placement ::operator new and ::operator delete, but allow
optimizations like new-expressions and delete-expressions do.
llvm-svn: 210137
elements from {}, rather than value-initializing them. This permits calling an
initializer-list constructor or constructing a std::initializer_list object.
(It would also permit initializing a const reference or rvalue reference if
that weren't explicitly prohibited by other rules.)
llvm-svn: 210091
trailing elements as a single loop, rather than sometimes emitting a nest of
several loops. This fixes a bug where CodeGen would sometimes try to emit an
expression with the wrong type for the element being initialized. Plus various
other minor cleanups to the IR produced for array new initialization.
llvm-svn: 210079
initializing an array unless we need it. Specifically, position the
creation of a new basic block after we've checked all of the cases that
bypass the need for it.
Fixes another leak in test/CodeGen* found by LSan.
llvm-svn: 207900
The MS ABI requires that we determine the vbptr offset if have a
virtual inheritance model. Instead, raise an error pointing to the
diagnostic when this happens.
This fixes PR18583.
Differential Revision: http://llvm-reviews.chandlerc.com/D2842
llvm-svn: 201824
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
This patch refactors microsoft record layout to be more "natural". The
most dominant change is that vbptrs and vfptrs are injected after the
fact. This simplifies the implementation and the math for the offest
for the first base/field after the vbptr.
llvm-svn: 198818
clang still doesn't emit the right llvm code when initializing multi-D arrays it seems.
For e.g. the following code would still crash for me on Windows 7, 64 bit:
auto f4 = new int[100][200][300]{{{1,2,3}, {4, 5, 6}}, {{10, 20, 30}}};
It seems that the final new loop that iterates through each outermost array and memsets it to zero gets confused with its final ptr arithmetic.
This patch ensures that it converts the pointer to the allocated type (int [200][300]) before incrementing it (instead of using the base type: 'int').
Richard somewhat squeamishly approved the patch (as a quick fix to potentially make it into 3.4) - while exhorting for a more optimized fix in the future. http://llvm-reviews.chandlerc.com/D2398
Thanks Richard!
llvm-svn: 197294
list, each element of the initializer list may provide more than one of the
base elements of the array. Be sure to initialize the right type and bump the
array pointer by the right amount.
llvm-svn: 196995
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
This reverts commit r193161.
It broke
void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));
Looks like we have to fix pr17639 first :-(
llvm-svn: 193162
names. For example, with this patch we now reject
void f1(void) __attribute__((alias("g1")));
This patch is implemented in CodeGen. It is quiet a bit simpler and more
compatible with gcc than implementing it in Sema. The downside is that the
errors only fire during -emit-llvm.
llvm-svn: 193161
This uses function prefix data to store function type information at the
function pointer.
Differential Revision: http://llvm-reviews.chandlerc.com/D1338
llvm-svn: 193058
The intent of getTypeOperand() was to yield an unqualified type.
However QualType::getUnqualifiedType() does not strip away qualifiers on
arrays.
N.B. This worked fine when typeid() was applied to an expression
because we would inject as implicit cast to the unqualified array type
in the AST.
llvm-svn: 191487
They were mostly copy&paste of each other, move it to CodeGenFunction. Of course
the two implementations have diverged over time; the one in CGExprCXX seems to
be the more modern one so I picked that one and moved it to CGClass which feels
like a better home for it. No intended functionality change.
llvm-svn: 189203
Based on Peter Collingbourne's destructor patches.
Prior to this change, clang was considering ?1 to be the complete
destructor and the base destructor, which was wrong. This lead to
crashes when clang tried to emit two LLVM functions with the same name.
In this ABI, TUs with non-inline dtors might not emit a complete
destructor. They are emitted as inline thunks in TUs that need them,
and they always delegate to the base dtors of the complete class and its
virtual bases. This change uses the DeferredDecls machinery to emit
complete dtors as needed.
Currently in clang try body destructors can catch exceptions thrown by
virtual base destructors. In the Microsoft C++ ABI, clang may not have
the destructor definition, in which case clang won't wrap the virtual
virtual base destructor calls in a try-catch. Diagnosing this in user
code is TODO.
Finally, for classes that don't use virtual inheritance, MSVC always
calls the base destructor (?1) directly. This is a useful code size
optimization that avoids emitting lots of extra thunks or aliases.
Implementing it also means our existing tests continue to pass, and is
consistent with MSVC's output.
We can do the same for Itanium by tweaking GetAddrOfCXXDestructor, but
it will require further testing.
Reviewers: rjmccall
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1066
llvm-svn: 186828
optimize, to follow the permissions granted in N3664. Under those rules, only
calls generated by new-expressions and delete-expressions are permitted to be
optimized, and direct calls to ::operator new and ::operator delete must be
treated as normal calls.
llvm-svn: 186799
This simplifies the core benefit of -flimit-debug-info by taking a more
systematic approach to avoid emitting debug info definitions for types
that only require declarations. The previous ad-hoc approach (3 cases
removed in this patch) had many holes.
The general approach (adding a bit to TagDecl and callback through
ASTConsumer) has been discussed with Richard Smith - though always open
to revision.
llvm-svn: 186262
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
1) Removed useless return value of CGCXXABI::EmitConstructorCall and CGCXXABI::EmitVirtualDestructorCall and implementations
2) Corrected last portion of CodeGenCXX/constructor-destructor-return-this to correctly test for non-'this'-return of virtual destructor calls
llvm-svn: 184330
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).
This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.
llvm-svn: 183872
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
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
This can yield dramatic speedups of dynamic_cast for simple inheritance trees,
at least with libsupc++. Neither libcxxabi nor libcxxrt make use of this
hint currently, it was never implemented because clang didn't support it.
There was some concern about the number of class hierarchy walks this change
introduces. If it turns out to be an issue we can add caching either at the cast
pair level or even deeper, but we also do a lot of walks in Sema so this
codepath is probably fairly optimized already.
llvm-svn: 174293
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
This fixes a regression from r162254, the optimizer has problems reasoning
about the smaller memcpy as it's often not safe to widen a store but making it
smaller is.
llvm-svn: 164917
be sure to delete the complete object pointer, not the original
pointer. This is necessary if the base being deleted is at a
non-zero offset in the complete object. This is only required
for objects with virtual destructors because deleting an object
via a base-class subobject when the base does not have a virtual
destructor is undefined behavior.
Noticed while reviewing the last four years of cxx-abi-dev
activity.
llvm-svn: 164597
the trap BB out of the individual checks and into a common function, to prepare
for making this code call into a runtime library. Rename the existing EmitCheck
to EmitTypeCheck to clarify it and to move it out of the way of the new
EmitCheck.
llvm-svn: 163451
* when checking that a pointer or reference refers to appropriate storage for a type, also check the alignment and perform a null check
* check that references are bound to appropriate storage
* check that 'this' has appropriate storage in member accesses and member function calls
llvm-svn: 162523
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
handy. It can be done, but we would have to build a derived-to-base cast
during codegen to compute the correct this pointer.
I will handle covariant returns next.
llvm-svn: 159350
David Blaikie