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
Use new `DIBuilder` API from LLVM r224482 to mutate `DICompositeType`s,
rather than changing them directly. This allows `DIBuilder` to track
otherwise orphaned cycles when `CollectContainingType()` creates a
self-reference.
Fixes PR21941.
llvm-svn: 224483
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
When emitting nested block definitions, the insert-at-point variant of
DIBuilder::insertDeclare() could be called with the insertion point set
to the end-of-BasicBlock sentinel, causing the parent pointer of the
CallInst to be set to the intentionally bogus value of the sentinel.
Fixed by conditionally invoking the correct version of insertDeclare().
rdar://problem/19034882
llvm-svn: 222487
After LLVM r222434, the Variables field of DISubprograms for forward
declarations will always be null. No need to keep code around to
delete them.
llvm-svn: 222437
This is a followup to r222373. A better solution to the problem solved
there is to not create the leaked nodes at all (we know that they will
never be used for forward declared functions anyway). To avoid bot
breakage in the interval between the cfe and llvm commits, add a check
that the nMDNode is not null before deleting it. This code can completely
go away after the LLVM part is in.
llvm-svn: 222433
While emitting debug information for function forward decalrations, we
create DISubprogram objects that aran't stored in the AllSubprograms
list, and thus won't get finalized by the DIBuilder. During the DIBuilder
finalize(), the temporary MDNode allocated for the DISubprogram
Variables field gets RAUWd with a non temporary DIArray. For the forward
declarations, simply delete that temporary node before we delete the
parent node, so that it doesn't leak.
llvm-svn: 222373
Currently this function would return nothing for functions or globals that
haven't seen a definition yet. Make it return a forward declaration that will
get RAUWed with the definition if one is seen at a later point. The strategy
used to implement this is similar to what's done for types: the forward
declarations are stored in a vector and post processed upon finilization to
perform the required RAUWs.
For now the only user of getDeclarationOrDefinition() is EmitUsingDecl(), thus
this patch allows to emit correct imported declarations even in the absence of
an actual definition of the imported entity.
(Another user will be the debug info generation for argument default values
that I need to resurect).
Differential Revision: http://reviews.llvm.org/D6173
llvm-svn: 222220
So DWARF5 specs out auto deduced return types as DW_TAG_unspecified_type
with DW_AT_name "auto", and GCC implements this somewhat, but it
presents a few problems to do this with Clang.
GCC's implementation only applies to member functions where the auto
return type isn't deduced immediately (ie: member functions of templates
or member functions defined out of line). In the common case of an
inline deduced return type function, GCC emits the DW_AT_type as the
deduced return type.
Currently GDB doesn't seem to behave too well with this debug info - it
treats the return type as 'void', even though the definition of the
function has the correctly deduced return type (I guess it sees the
return type the declaration has, doesn't understand it, and assumes
void). This means the function's ABI might be broken (non-trivial return
types, etc), etc.
Clang, on the other hand doesn't track this particular case of a
deducable return type that is deduced immediately versus one that is
deduced 'later'. So if we implement the DWARF5 representation, all
deducible return type functions would get adverse GDB behavior
(including deduced return type lambda functions, inline deduced return
type functions, etc).
Also, we can't just do this for auto types that are not deduced -
because Clang marks even the declaration's return type as deduced (&
provides the underlying type) once a definition is seen that allows the
deduction. So we have to ignore even deduced types - but we can't do
that for auto variables (because this representation only applies to
function declarations - variables and function definitions need the real
type so the function can be called, etc) so we'd need to add an extra
flag to the type unwrapping/creation code to indicate when we want to
see through deduced types and when we don't. It's also not as simple as
just checking at the top level when building a function type (for one
thing, we reuse the function type building for building function pointer
types which might also have 'auto' in them - but be the type of a
variable instead) because the auto might be arbitrarily deeply nested
("auto &", "auto (*)()", etc...)
So, with all that said, let's do the simple thing that works in existing
debuggers for now and treat these functions the same way we do function
templates and implicit special members: omit them from the member list,
since they can't be correctly called anyway (without knowing the return
type the ABI isn't know and a function call could put the arguments in
the wrong place) so they're not much use to the user.
At some point in the future, when GDB understands the DWARF5
representation better it might be worth plumbing through the extra type
builder handling to avoid looking through AutoType for some callers,
etc...
llvm-svn: 221704
When we are generating the global initializer functions, we call
CGDebugInfo::EmitFunctionStart() with a valid decl which is describing
the initialized global variable. Do not update the DeclCache with this
key as it will overwrite the the cached variable DIGlobalVariable with
the newly created artificial DISubprogram.
One could wonder if we should put artificial subprograms in the DIE tree
at all (there are vaild uses for them carrying line information though).
llvm-svn: 221385
This fixes a corner-case where __uuidof as a template argument would
result in us trying to emit a GLValue as an RValue. This would lead to
a crash down the road.
llvm-svn: 220585
The previous IR representation used the non-lexical decl context, which
placed the definitions in the same scope as the declarations (ie: within
the class) - this was hidden by the fact that LLVM currently doesn't
respect the context of global variable definitions at all, and always
puts them at the top level (as direct children of the compile_unit).
Having the correct lexical scope improves source fidelity and simplify
backend global variable emission (with changes coming shortly).
Doing something similar for non-member global variables would help
simplify/cleanup things further (see FIXME in the commit) and provide
similar source fidelity benefits to the final debug info.
llvm-svn: 220488
Plumb through the full QualType of the TemplateArgument::Declaration, as
it's insufficient to only know whether the type is a reference or
pointer (that was necessary for mangling, but insufficient for debug
info). This shouldn't increase the size of TemplateArgument as
TemplateArgument::Integer is still longer by another 32 bits.
Several bits of code were testing that the reference-ness of the
parameters matched, but this seemed to be insufficient (various other
features of the type could've mismatched and wouldn't've been caught)
and unnecessary, at least insofar as removing those tests didn't cause
anything to fail.
(Richard - perchaps you can hypothesize why any of these checks might
need to test reference-ness of the parameters (& explain why
reference-ness is part of the mangling - I would've figured that for the
reference-ness to be different, a prior template argument would have to
be different). I'd be happy to add them in/beef them up and add test
cases if there's a reason for them)
llvm-svn: 219900
When lazily constructing static member variable declarations (when
the vtable optimization fires and the definition of the type is omitted
(or built later, lazily), but the out of line definition of the static
member is provided and must be described in debug info) ensure we use
the canonical declaration when computing the file, line, etc for that
declaration (rather than the definition, which is also a declaration,
but not the canonical one).
llvm-svn: 219736
By leaving these members out of the member list, we avoid them being
emitted into type unit definitions - while still allowing the
definition/declaration to be injected into the compile unit as expected.
llvm-svn: 219101
By leaving these members out of the member list, we avoid them being
emitted into type unit definitions - while still allowing the
definition/declaration to be injected into the compile unit as expected.
llvm-svn: 219100
Complex address expressions are no longer part of DIVariable, but
rather an extra argument to the debug intrinsics.
http://reviews.llvm.org/D4919
rdar://problem/17994491
llvm-svn: 218788
Complex address expressions are no longer part of DIVariable, but
rather an extra argument to the debug intrinsics.
http://reviews.llvm.org/D4919
rdar://problem/17994491
llvm-svn: 218777
Most of the debug info emission is powered essentially from function
definitions - if we emit the definition of a function, we emit the types
of its parameters, the members of those types, and so on and so forth.
For types that aren't referenced even indirectly due to this - because
they only appear in temporary expressions, not in any named variable, we
need to explicitly emit/add them as is done here. This is not the only
case of such code, and we might want to consider handling "void
func(void*); ... func(new T());" (currently debug info for T is not
emitted) at some point, though GCC doesn't. There's a much broader
solution to these issues, but it's a lot of work for possibly marginal
gain (but might help us improve the default -fno-standalone-debug
behavior to be even more aggressive in some places). See the original
review thread for more details.
Patch by jyoti allur (jyoti.yalamanchili@gmail.com)!
Differential Revision: http://reviews.llvm.org/D2498
llvm-svn: 218390
Due to the possible presence of return-by-out parameters, using the LLVM
argument number count when numbering debug info arguments can end up
off-by-one. This could produce two arguments with the same number, which
would in turn cause LLVM to emit only one of those arguments (whichever
it found last) or assert (r215157).
llvm-svn: 215227
