The backend will now use the generic 'returned' attribute to form tail calls where possible, as well as avoid save-restores of 'this' in some cases (specifically the cases that matter for the ARM C++ ABI).
This patch also reverts a prior front-end only partial implementation of these optimizations, since it's no longer required.
llvm-svn: 184205
the result of a cast-to-reference-type lifetime-extends the object to which the
reference inside the cast binds.
This requires us to look for subobject adjustments on both the inside and the
outside of the MaterializeTemporaryExpr when looking for a temporary to
lifetime-extend (which we also need for core issue 616, and possibly 1213).
llvm-svn: 184024
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
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.
llvm-svn: 183859
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.
llvm-svn: 183721
Two variables with the same name declared in two if conditions in the same
scope are no longer coalesced into one.
rdar://problem/14024005
llvm-svn: 183597
There seems to have been some erroneous code attempting to describe the
ABI of parameters (non-trivial record parameters are passed by
reference). This would break the type of the function (especially when
it caused a mismatch between the type of a declaration & a definition)
causing PR14763 and PR14645.
llvm-svn: 183329
Also addresses a review comment from John from on r180985 by removing
the "== -1" check, since it's now reusing the correct code which has the
comment.
llvm-svn: 183318
In an effort to make -flimit-debug-info more consistent I over-shot the
mark & made types used via typedefs never produce definitions in the
debug info (even if the type was used in a way that would require a
definition).
The fix for this is to do exactly what I was hoping to do at some point
- plumb the declaration/definition choice through the various layers of
"CreateType" in CGDebugInfo. In this way we can produce declarations
whenever they are sufficient & definitions otherwise - including when
qualifiers are used, for example (discovered in PR14467). This may not
be complete (there may be other types/situations where we need to
propagate the "declaration/definition" choice) but it lays the basic
foundation which we can enhance in future iterations.
llvm-svn: 183296
handle temporaries which have been lifetime-extended to static storage duration
within constant expressions. This correctly handles nested lifetime extension
(through reference members of aggregates in aggregate initializers) but
non-constant-expression emission hasn't yet been updated to do the same.
llvm-svn: 183283
Template functions (and member functions of class templates) present the same
problem as inline functions. They need to be uniqued, so we need to assign
VisibleNoLinkage linkage to types defined in them.
llvm-svn: 183222
which is lifetime-extended by a reference binding. An additional temporary is
created for such a bitfield access (although we have no explicit AST
representation for it).
llvm-svn: 183095
clang would incorrectly not allow the following:
int x = true ? (throw 1) : 2;
The problem exists because we don't see beyond the parens.
This, in turn, causes us to believe that we are choosing between void
and int which we diagnose as an error.
Instead, allow clang to see the 'throw' inside the parens.
llvm-svn: 183085
syntactic form in template instantiation. Previously, this blocked the
reversion and we ended up losing inner CXXBindTemporaryExprs (and thus
forgetting to call destructors!).
llvm-svn: 182969
While we can't yet emit vbtables, this allows us to find virtual bases
of objects constructed in other TUs.
This make iostream hello world work, since basic_ostream virtually
inherits from basic_ios.
Differential Revision: http://llvm-reviews.chandlerc.com/D795
llvm-svn: 182870
MSVC's class data is always comdat, so clang's should always be
linkonce_odr in LLVM IR.
Reviewers: pcc
Differential Revision: http://llvm-reviews.chandlerc.com/D838
llvm-svn: 182865
John noticed that the fix for pr15930 (r181981) didn't handle indirect
uses of local types. For example, a pointer to local struct, or a
function that returns it.
One way to implement this would be to recursively look for local
types. This would look a lot like the linkage computation itself for
types.
To avoid code duplication and utilize the existing linkage cache, this
patch just makes the computation of "type with no linkage but
externally visible because it is from an inline function" part of the
linkage computation itself.
llvm-svn: 182711
Perhaps we should just suppress this, rather than erroring, but since we
have the infrastructure for it I figured I'd use it - if this is
determined to be not the right thing we should probably remove that
infrastructure entirely. I guess it's lying around from the early days
of implementing debug info support.
llvm-svn: 182673
This resolves the last of the PR14606 failures in the GDB 7.5 test
suite. (but there are still unresolved issues in the imported_decl case
- we need to implement optional/lazy decls for functions & variables
like we already do for types)
llvm-svn: 182329
This reverts commit r181947 (git d2990ce56a16050cac0d7937ec9919ff54c6df62 )
This addresses one of the two issues identified in r181947, ensuring
that types imported via using declarations only result in a declaration
being emitted for the type, not a definition. The second issue (emitting
using declarations that are unused) is hopefully an acceptable increase
as the real fix for this would be a bit difficult (probably at best we
could record which using directives were involved in lookups - but may
not have been the result of the lookup).
This also ensures that DW_TAG_imported_declarations (& directives) are
not emitted in line-tables-only mode as well as ensuring that typedefs
only require/emit declarations (rather than definitions) for referenced
types.
llvm-svn: 182231
Stephen Lin