backtrace.c File Reference

WASM implementation for backtrace (no-op in web) More...

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Functions
void	backtrace_t_free (backtrace_t *bt)
	Free backtrace symbols.
void	backtrace_print (const char *label, const backtrace_t *bt, int skip_frames, int max_frames, backtrace_frame_filter_t filter)
	Print backtrace with dual output: colored stderr + plain log file.
void	backtrace_print_many (const char *label, const backtrace_t *bts, int count)
	Print multiple backtraces.
void	backtrace_symbolize (backtrace_t *bt)
	Symbolize bt->ptrs into bt->symbols.

Detailed Description

WASM implementation for backtrace (no-op in web)

Definition in file platform/wasm/backtrace.c.

Function Documentation

backtrace_print()

void backtrace_print	(	const char *	label,
		const backtrace_t *	bt,
		int	skip_frames,
		int	max_frames,
		backtrace_frame_filter_t	filter
	)

Print backtrace with dual output: colored stderr + plain log file.

Intelligently formats and routes backtraces to multiple destinations:

• stderr: Colored output with semantic highlighting (for interactive debugging)
• log file (if logging): Plain ASCII without ANSI codes (for file parsing)

This dual-output design ensures readable terminal output during development while keeping log files clean and searchable in production.

Output Format

Terminal output example:

=== Backtrace: Error ===
[0] 0x7f1234567890 in main() [src/main.c:42]
[1] 0x7f1234567800 in process_request() [src/network.c:128]
[2] 0x7f1234567700 in send_data() [src/io.c:67]

Log file (same content, no colors):

=== Backtrace: Error ===
[0] 0x7f1234567890 in main() [src/main.c:42]
...

Parameters

label	Header label (e.g., "Backtrace", "Leak trace", "Assertion failure")
bt	Backtrace to print (must not be NULL, must be symbolized via backtrace_capture_and_symbolize)
skip_frames	Number of frames to skip from start (0 = include all, 1 = skip first frame, etc.)
max_frames	Maximum frames to print (0 = unlimited, 5 = first 5 frames only)
filter	Optional callback to selectively skip frames (e.g., filter internal frames) Return true to skip frame, false to include. NULL = no filtering.

Note

Backtrace must be symbolized. Unsymbolized (raw hex) traces are less useful.

Frame filtering is useful to focus on application code, excluding:

• lib/platform internal calls
• lib/log infrastructure
• Exception handling wrappers

See also

backtrace_format() for buffer-based output (safe for log system)

Definition at line 14 of file platform/wasm/backtrace.c.

                                                      {
  (void)label;
  (void)bt;
  (void)skip_frames;
  (void)max_frames;
  (void)filter;
  // No-op - backtraces not available in WASM
}

backtrace_print_many()

void backtrace_print_many	(	const char *	label,
		const backtrace_t *	bts,
		int	count
	)

Print multiple backtraces.

Convenience function for iterating and printing multiple backtrace_t entries.

Parameters

label	Header label for all backtraces
bts	Array of backtrace structures
count	Number of backtraces to print

Definition at line 24 of file platform/wasm/backtrace.c.

                                                                                {
  (void)label;
  (void)bts;
  (void)count;
  // No-op
}

backtrace_symbolize()

void backtrace_symbolize

(

backtrace_t *

bt

)

Symbolize bt->ptrs into bt->symbols.

Calls platform_backtrace_symbols() to convert raw addresses to symbol strings. This is a no-op if symbols are already set (already symbolized).

Parameters

bt	Backtrace structure to symbolize (must not be NULL)

Definition at line 31 of file platform/wasm/backtrace.c.

                                          {
  (void)bt;
  // No-op - symbolization not available in WASM
}

backtrace_t_free()

void backtrace_t_free

(

backtrace_t *

bt

)

Free backtrace symbols.

Calls platform_backtrace_symbols_destroy() to free the symbols array. Nulls the symbols pointer after freeing.

Parameters

bt	Backtrace structure (must not be NULL)

Definition at line 9 of file platform/wasm/backtrace.c.

                                       {
  (void)bt;
  // No-op - no resources to free in WASM
}