`Stream` will be qualified as `AK::Stream` until we remove the
`Core::Stream` namespace. `IODevice` now reuses the `SeekMode` that is
defined by `SeekableStream`, since defining its own would require us to
qualify it with `AK::SeekMode` everywhere.
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Doesn't use them in libc headers so that those don't have to pull in
AK/Platform.h.
AK_COMPILER_GCC is set _only_ for gcc, not for clang too. (__GNUC__ is
defined in clang builds as well.) Using AK_COMPILER_GCC simplifies
things some.
AK_COMPILER_CLANG isn't as much of a win, other than that it's
consistent with AK_COMPILER_GCC.
The previous solution of "lol whats a UB" was not nice and tripped over
itself when it was run under UBSAN, fix this by doing explicit
byte-by-byte reads where needed.
The format of the address range section is different between DWARF
version 4 and version 5. This meant that we parsed programs compiled
with `-gdwarf-4` incorrectly.
The parameter of this operator is an unsigned LEB128 integer, so it can
be more than 1 byte in length. If we only read 1 byte, we might mess up
the offsets for the instructions following it.
Our implementation (naively) assumes that there is a one-to-one
correspondence between compilation units and line programs, and that
their orders are identical. This is not the case for embedded resources,
as Clang only creates line programs for it, but not compilation units.
This mismatch caused an assertion failure, which made generating
backtraces for GUI applications impossible. This commit introduces a
hack that skips creating CompilationUnit objects for LinePrograms that
come from embedded resources.
These forms were introduced in DWARF5, and have a fair deal of
advantages over the more traditional encodings: they reduce the size of
the binary and the number of relocations.
GCC does not emit these with `-g1` by default, but Clang does at all
debug levels.
This will be needed when we add `DW_FORM_strx*` and `DW_FORM_addrx*`
support, which requires us to fetch `DW_AT_str_offsets_base` and
`DW_AT_addr_base` attributes from the parent compilation unit. This
can't be done as we read the values, because it would create infinite
recursion (as we might try to parse the compilation unit's
`DW_FORM_strx*` encoded name before we get to the attribute). Having
getters ensures that we will perform lookups if they are needed.
Previously, we only supported DIEs with a contiguous address ranges and
ignored ones with a non-contiguous set of ranges.
We now check if a DIE has the DW_AT_ranges attribute, and if it does we
parse its range list.
This improves the quality of our backtraces - we previously missed many
inlined function calls because their DIEs had non-contigues address
ranges.
This adds support for parsing DWARF "range lists", which are identified
by the DW_AT_ranges form.
They contain code addresses for DIEs whose location is not contiguous.
These API's are used in a variety of ways when building the die cache.
Each AbbreviationEntry has vector and other members, so avoid copying
it at all costs.
This algorithm is both iterative and recursive, so allocating on every
recursion, or when iterating each child is extremely costly.
Instead allow the on stack DIE to be re-initialized so it can be reused.
This helps us avoid weird truncation issues and fixes a bug on Clang
builds where truncation while reading caused the DIE offsets following
large LEB128 numbers to be incorrect. This removes the need for the
separate `LongUnsignedNumber` type.
This LineProgram instruction is emitted by Clang. Although we currently
have no use for it (it's mostly a debugger feature), we need to handle
this opcode, as otherwise CrashReporter wouldn't work.
