Implement -femit-local-var-lifetime which adds local (stack) variable lifetime annotation to LLVM IR, which enables sharing stack space for variables whose lifetimes do not overlap.
Resolves issue #2227
This is not enabled by default yet, to prevent miscompilation due to bugs (should be enabled in future for optimization levels > 0, and when sanitizers are enabled).
As the initializer might just as well not be computable at compile-time.
Fixes such a case in `bug6985()` in dmd-testsuite's
`compilable/interpret3.d`.
* Newly require `-link-defaultlib-shared` for implicit dllimport.
E.g., this enables to compile druntime DLL with `-fvisibility=public`
for pure exports and no (local) imports (such as builtin TypeInfos).
* `-link-defaultlib-shared` alone now only implicitly imports symbols
from druntime/Phobos.
This simplifies building complex DLLs linked against a bunch of
static libs (dub only supports static lib dependencies!); the static
libs don't need to be compiled with `-fvisibility=public` anymore
(if the DLL itself isn't either), `-link-defaultlib-shared` is
sufficient.
This is mainly useful for existing DLLs with explicit exports, to make
them link against *shared* druntime/Phobos and so end up with a single
druntime/Phobos for the whole process.
Init symbols, TypeInfos (classes only) & vtables - unless defined in a
root module. For explicitly exported aggregates, or, with
`-fvisibility=public`, all aggregates.
This fixes an issue where any instantiation of TypeInfo in the final
output would lead to a cryptic error with no file or line information.
This change brings ldc in line with dmd's reporting of the same error,
which at least gives file and line information to discover the problem.
The semantics were almost identical, except for DtoIsTemplateInstance()
checking the specified Dsymbol and its parents, while isInstantiated()
starts from its parent and ignores the symbol itself.
After a quick glance, we seem to have fed it with {Aggregate,Func,Var}
Declarations only, so should be fine with the default front-end variant.
I.e., *define* templated symbols in each referencing compilation unit
when using discardable linkonce_odr linkage, analogous to C++.
This makes each compilation unit self-sufficient wrt. templated symbols,
which also means increased opportunity for inlining and less need for
LTO. There should be no more undefined symbol issues caused by buggy
template culling.
The biggest advantage is that the optimizer can discard unused
linkonce_odr symbols early instead of optimizing and forwarding to the
assembler. So this is especially useful with -O to decrease compilation
times and can at least in some scenarios greatly outweigh the
(potentially very much) higher number of symbols defined by the glue
layer.
Libraries compiled with -linkonce-templates can generally not be linked
against dependent code compiled without -linkonce-templates; the other
way around works.
Fixing a regression in dmd-testsuite's compilable/test8543.d, where CTFE
changes seem not to consider such previous LDC-specific CastExp as lvalue
anymore.
Fixes#3490 by avoiding unnecessary extra key allocations for the literals cache etc.
Also gets rid of code duplication and improves IRState encapsulation.
I.e., use the expression's lvalue as operand for "m" memory inputs, like
GDC. Previously, this was restricted to output operands ("=m"); input
operands were still using the expression's rvalue (and so required an
explicit address-of operator for variables).
Making it obvious which of the two operations is performed, reducing
call args and making sure a global isn't defined multiple times via
`defineGlobal()`.
The only [intended] functional change is in gen/trycatchfinally.cpp,
where I inserted a check for an existing __cpp_type_info_ptr global when
emitting a catch for C++ exceptions.
The previous check wouldn't check intermediate aggregates for static-ness,
that was one problem. The other was the assertion that the outer function
can be reached as long as there are no static functions inbetween, which
isn't always the case, as issue #1864 clearly shows, which is resolved by
this.
