Add the ability to generate a C source file, which is in addition to the
existing functionality of generating binary.
An example of the generated source:
```c
#ifdef __APPLE__
#define FORMATTER_SECTION "__DATA_CONST,__lldbformatters"
#else
#define FORMATTER_SECTION ".lldbformatters"
#endif
__attribute__((used, section(FORMATTER_SECTION)))
unsigned char _Account_synthetic[] =
// version
"\x01"
// remaining record size
"\x15"
// type name size
"\x07"
// type name
"Account"
// flags
"\x00"
// sig_get_num_children
"\x02"
// program size
"\x02"
// program
"\x20\x01"
// sig_get_child_at_index
"\x04"
// program size
"\x06"
// program
"\x02\x20\x00\x23\x11\x60"
;
```
Changes `formatter_bytecode.compile_file` to return a `BytecodeSection`
value. The `BytecodeSection` holds the data that needs to be emitted to
an `__lldbformatters` section.
The `BytecodeSection` currently provides `write_binary`, but will be
updated in a follow up commit to include `write_source` which will allow
the data to be emitted as C source code, or Swift source code. This will
make it easier to integrate into build systems, as it's easier to get
data into a binary via source code, than as a raw binary file.
Updates formatter_bytecode.py to support compilation and disassembly for
synthetic formatters, in other words support for multiple functions
(signatures).
This includes a number of other changes:
* String parsing and encoding have bugs fixed
* CLI args are updated, primarily to support an output file
* Added uleb encoding/decoding support
This work is a prelude the ongoing work of a Python to formatter
bytecode compiler. The python compiler to emit assembly, and this module
(formatter_bytecode) will compile it into binary bytecode.
`GetSyntheticValue` in synthetic providers which need to operate on raw
root values, but will often want to use the synthetic value of children,
or nested children.
This PR adds a proof-of-concept for a bytecode designed to ship and
run LLDB data formatters. More motivation and context can be found in
the formatter-bytecode.rst file and on discourse.
https://discourse.llvm.org/t/a-bytecode-for-lldb-data-formatters/82696
Relanding with a fix for a case-sensitive path.
This PR adds a proof-of-concept for a bytecode designed to ship and
run LLDB data formatters. More motivation and context can be found in
the formatter-bytecode.rst file and on discourse.
https://discourse.llvm.org/t/a-bytecode-for-lldb-data-formatters/82696
Relanding with a fix for a case-sensitive path.
