Gdb/IPA-Protocol-Objects
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30.1.1 IPA Protocol Objects
The commands sent to and results received from agent may contain some complex data types called objects.
The in-process agent is running on the same machine with GDB or GDBserver, so it doesn’t have to handle as much differences between two ends as remote protocol (see Remote Protocol) tries to handle. However, there are still some differences of two ends in two processes:
- word size. On some 64-bit machines, GDB or GDBserver can be compiled as a 64-bit executable, while in-process agent is a 32-bit one.
- ABI. Some machines may have multiple types of ABI, GDB or GDBserver is compiled with one, and in-process agent is compiled with the other one.
Here are the IPA Protocol Objects:
- agent expression object. It represents an agent expression (see Agent Expressions).
- tracepoint action object. It represents a tracepoint action (see Tracepoint Action Lists) to collect registers, memory, static trace data and to evaluate expression.
- tracepoint object. It represents a tracepoint (see Tracepoints).
The following table describes important attributes of each IPA protocol object:
| Name | Size | Description |
|---|---|---|
| agent expression object | ||
| length | 4 | length of bytes code |
| byte code | length
|
contents of byte code |
| tracepoint action for collecting memory | ||
| ’M’ | 1 | type of tracepoint action |
| addr | 8 | if basereg is ‘-1’, addr is the
address of the lowest byte to collect, otherwise |
| len | 8 | length of memory for collecting |
| basereg | 4 | the register number containing the starting
memory address for collecting. |
| tracepoint action for collecting registers | ||
| ’R’ | 1 | type of tracepoint action |
| tracepoint action for collecting static trace data | ||
| ’L’ | 1 | type of tracepoint action |
| tracepoint action for expression evaluation | ||
| ’X’ | 1 | type of tracepoint action |
| agent expression | length of | agent expression object |
| tracepoint object | ||
| number | 4 | number of tracepoint |
| address | 8 | address of tracepoint inserted on |
| type | 4 | type of tracepoint |
| enabled | 1 | enable or disable of tracepoint |
| step_count | 8 | step |
| pass_count | 8 | pass |
| numactions | 4 | number of tracepoint actions |
| hit count | 8 | hit count |
| trace frame usage | 8 | trace frame usage |
| compiled_cond | 8 | compiled condition |
| orig_size | 8 | orig size |
| condition | 4 if condition is NULL otherwise length of | zero if condition is NULL, otherwise is |
| actions | variable | numactions number of tracepoint action object |
Next: IPA Protocol Commands, Up: In-Process Agent Protocol [Contents][Index]
