Since elements of most kinds of DICompositeType have back references,
most are involved in uniquing cycles. Except via the ODR 'identifier:'
field, which doesn't care about the storage type (see r266549),
they have no hope of being uniqued.
Distinct nodes are far more efficient, so use them for most kinds of
DICompositeType definitions (i.e., when DIType::isForwardDecl is false).
The exceptions:
- DW_TAG_array_type, since their elements never have back-references
and they never have ODR 'identifier:' fields;
- DW_TAG_enumeration_type when there is no ODR 'identifier:' field,
since their elements usually don't have back-references.
This breaks the last major uniquing cycle I'm aware of in the debug info
graph. The impact won't be enormous for C++ because references to
ODR-uniqued nodes still use string-based DITypeRefs; but this should
prevent a regression in C++ when we drop the string-based references.
This wouldn't have been reasonable until r266549, when composite types
stopped relying on being uniqued by structural equivalence to prevent
blow-ups at LTO time.
llvm-svn: 266556
With this change, most 'g' options are rejected by CompilerInvocation.
They remain only as Driver options. The new way to request debug info
from cc1 is with "-debug-info-kind={line-tables-only|limited|standalone}"
and "-dwarf-version={2|3|4}". In the absence of a command-line option
to specify Dwarf version, the Toolchain decides it, rather than placing
Toolchain-specific logic in CompilerInvocation.
Also fix a bug in the Windows compatibility argument parsing
in which the "rightmost argument wins" principle failed.
Differential Revision: http://reviews.llvm.org/D13221
llvm-svn: 249655
Update testcases after LLVM change r243774.
Most of these had no need to check `tag:` field, but did so as a way of
getting to the `name:` field. In a few cases I've converted the `tag:`
checks to `arg:` or `CHECK-NOT: arg:`.
llvm-svn: 243775
and as artificial local variables in the debug info.
This is a follow-up to r236059. We can't get rid of the local variables
entirely because the gdb buildbot depends on them, but we can mark them
as artificial while still emitting the correct debug info. As I learned
from review comments other compilers also follow this model.
A paired commit in LLVM temporarily relaxes the debug info verifier to
not check the integrity of DW_OP_bit_pieces of artificial variables.
rdar://problem/20730771
llvm-svn: 236125
LLVM r236120 renamed debug info IR constructs to use a `DI` prefix, now
that the `DIDescriptor` hierarchy has been gone for about a week. This
commit was generated using the rename-md-di-nodes.sh upgrade script
attached to PR23080, followed by running clang-format-diff.py on the
`lib/` portion of the patch.
llvm-svn: 236121
in the debug info. This patch deletes a hack that emits the members
of local anonymous unions as local variables.
Besides being morally wrong, the existing representation using local
variables breaks internal assumptions about the local variables' storage
size.
Compiling
```
void fn1() {
union {
int i;
char c;
};
i = c;
}
```
with -g -O3 -verify will cause the verifier to fail after SROA splits
the 32-bit storage for the "local variable" c into two pieces because the
second piece is clearly outside the 8-bit range that is expected for a
variable of type char. Given the choice I'd rather fix the debug
representation than weaken the verifier.
Debuggers generally already know how to deal with anonymous unions when
they are members of C++ record types, but they may have problems finding
the local anonymous struct members in the expression evaluator.
rdar://problem/20730771
llvm-svn: 236059
sure that a debugger can find them when stepping through code,
for example from the included testcase:
12 int test_it() {
13 c = 1;
14 d = 2;
-> 15 a = 4;
16 return (c == 1);
17 }
18
(lldb) p a
(int) $0 = 2
(lldb) p c
(int) $1 = 2
(lldb) p d
(int) $2 = 2
and a, c, d are all part of the file static anonymous union:
static union {
int c;
int d;
union {
int a;
};
struct {
int b;
};
};
Fixes PR19221.
llvm-svn: 205952
Peter Collingbourne