Previously, lldb mistook fields in anonymous union in a struct as the direct
field of the struct, which causes lldb crashes due to multiple fields sharing
the same offset in a struct. This patch fixes it.
MSVC generated pdb doesn't have the debug info entity representing a anonymous
union in a struct. It looks like the following:
```
struct S {
union {
char c;
int i;
};
};
0x1004 | LF_FIELDLIST [size = 40]
- LF_MEMBER [name = `c`, Type = 0x0070 (char), offset = 0, attrs = public]
- LF_MEMBER [name = `i`, Type = 0x0074 (int), offset = 0, attrs = public]
0x1005 | LF_STRUCTURE [size = 32] `S`
unique name: `.?AUS@@`
vtable: <no type>, base list: <no type>, field list: 0x1004
```
Clang generated pdb is similar, though due to the [[ https://github.com/llvm/llvm-project/issues/57999 | bug ]],
it's not more useful than the debug info above. But that's not very relavent,
lldb should still be able to understand MSVC geneerated pdb.
```
0x1003 | LF_UNION [size = 60] `S::<unnamed-tag>`
unique name: `.?AT<unnamed-type-$S1>@S@@`
field list: <no type>
options: forward ref (= 0x1003) | has unique name | is nested, sizeof 0
0x1004 | LF_FIELDLIST [size = 40]
- LF_MEMBER [name = `c`, Type = 0x0070 (char), offset = 0, attrs = public]
- LF_MEMBER [name = `i`, Type = 0x0074 (int), offset = 0, attrs = public]
- LF_NESTTYPE [name = ``, parent = 0x1003]
0x1005 | LF_STRUCTURE [size = 32] `S`
unique name: `.?AUS@@`
vtable: <no type>, base list: <no type>, field list: 0x1004
options: contains nested class | has unique name, sizeof 4
0x1006 | LF_FIELDLIST [size = 28]
- LF_MEMBER [name = `c`, Type = 0x0070 (char), offset = 0, attrs = public]
- LF_MEMBER [name = `i`, Type = 0x0074 (int), offset = 0, attrs = public]
0x1007 | LF_UNION [size = 60] `S::<unnamed-tag>`
unique name: `.?AT<unnamed-type-$S1>@S@@`
field list: 0x1006
options: has unique name | is nested | sealed, sizeof
```
This patch delays the FieldDecl creation when travesing LF_FIELDLIST so we know
if there are multiple fields are in the same offsets and are able to group them
into different anonymous unions based on offsets. Nested anonymous union will
be flatten into one anonymous union, because we simply don't have that info, but
they are equivalent in terms of union layout.
Differential Revision: https://reviews.llvm.org/D134849
Based on post-commit review discussion on
2bd84938470bf2e337801faafb8a67710f46429d with Richard Smith.
Other uses of forcing HasEmptyPlaceHolder to false seem OK to me -
they're all around pointer/reference types where the pointer/reference
token will appear at the rightmost side of the left side of the type
name, so they make nested types (eg: the "int" in "int *") behave as
though there is a non-empty placeholder (because the "*" is essentially
the placeholder as far as the "int" is concerned).
This was originally committed in 277623f4d5a672d707390e2c3eaf30a9eb4b075c
Reverted in f9ad1d1c775a8e264bebc15d75e0c6e5c20eefc7 due to breakages
outside of clang - lldb seems to have some strange/strong dependence on
"char [N]" versus "char[N]" when printing strings (not due to that name
appearing in DWARF, but probably due to using clang to stringify type
names) that'll need to be addressed, plus a few other odds and ends in
other subprojects (clang-tools-extra, compiler-rt, etc).
These test don't execute the binaries they build, and so they don't need
to build for the host. By hardcoding the target, we don't have do xfail
or skip them for targets which don't have the appropriate support in
clang(-cl).
LLDB has three major testing strategies: unit tests, tests that exercise
the SB API though dotest.py and what we currently call lit tests. The
later is rather confusing as we're now using lit as the driver for all
three types of tests. As most of this grew organically, the directory
structure in the LLDB repository doesn't really make this clear.
The 'lit' tests are part of the root and among these tests there's a
Unit and Suite folder for the unit and dotest-tests. This layout makes
it impossible to run just the lit tests.
This patch changes the directory layout to match the 3 testing
strategies, each with their own directory and their own configuration
file. This means there are now 3 directories under lit with 3
corresponding targets:
- API (check-lldb-api): Test exercising the SB API.
- Shell (check-lldb-shell): Test exercising command line utilities.
- Unit (check-lldb-unit): Unit tests.
Finally, there's still the `check-lldb` target that runs all three test
suites.
Finally, this also renames the lit folder to `test` to match the LLVM
repository layout.
Differential revision: https://reviews.llvm.org/D68606
llvm-svn: 374184
