ldbg.cpp File Reference

#include "precompiled.h"
#include "lib/sysdep/sysdep.h"
#include "lib/debug.h"
#include <algorithm>
#include <cstring>
#include <sys/syscall.h>
#include <execinfo.h>

Include dependency graph for ldbg.cpp:

Functions
void *	debug_GetCaller (void *context, const wchar_t *lastFuncToSkip)
	return the caller of a certain function on the call stack. More...
Status	debug_DumpStack (wchar_t *buf, size_t max_chars, void *context, const wchar_t *lastFuncToSkip)
	write a complete stack trace (including values of local variables) into the specified buffer. More...
Status	debug_ResolveSymbol (void *ptr_of_interest, wchar_t *sym_name, wchar_t *file, int *line)
	read and return symbol information for the given address. More...
void	debug_SetThreadName (const char *name)
	inform the debugger of the current thread's name. More...

Function Documentation

debug_DumpStack()

Status debug_DumpStack	(	wchar_t *	buf,
		size_t	maxChars,
		void *	context,
		const wchar_t *	lastFuncToSkip
	)

write a complete stack trace (including values of local variables) into the specified buffer.

Parameters

buf	Target buffer.
maxChars	Max chars of buffer (should be several thousand).
context	Platform-specific representation of execution state (e.g. Win32 CONTEXT). either specify an SEH exception's context record or use debug_CaptureContext to retrieve the current state. Rationale: intermediates such as debug_DisplayError change the context, so it should be captured as soon as possible.
lastFuncToSkip	Is used for omitting error-reporting functions like debug_OnAssertionFailure from the stack trace. It is either 0 (skip nothing) or a substring of a function's name (this allows platform-independent matching of stdcall-decorated names). Rationale: this is safer than specifying a fixed number of frames, which can be incorrect due to inlining.

Returns

Status; ERR::REENTERED if reentered via recursion or multithreading (not allowed since static data is used).

debug_GetCaller()

void * debug_GetCaller	(	void *	context,
		const wchar_t *	lastFuncToSkip
	)

return the caller of a certain function on the call stack.

this function is useful for recording (partial) stack traces for memory allocation tracking, etc.

Parameters

context,lastFuncToSkip

- see debug_DumpStack

Returns

address of the caller

debug_ResolveSymbol()

Status debug_ResolveSymbol	(	void *	ptr_of_interest,
		wchar_t *	sym_name,
		wchar_t *	file,
		int *	line
	)

read and return symbol information for the given address.

NOTE: the PDB implementation is rather slow (~500 us).

Parameters

ptr_of_interest	address of symbol (e.g. function, variable)
sym_name	optional out; holds at least DEBUG_SYMBOL_CHARS; receives symbol name returned via debug info.
file	optional out; holds at least DEBUG_FILE_CHARS; receives base name only (no path; see rationale in wdbg_sym) of source file containing the symbol.
line	optional out; receives source file line number of symbol.

note: all of the output parameters are optional; we pass back as much information as is available and desired.

Returns

Status; INFO::OK iff any information was successfully retrieved and stored.

debug_SetThreadName()

void debug_SetThreadName

(

const char *

name

)

inform the debugger of the current thread's name.

(threads are easier to keep apart when they are identified by name rather than TID.)