S32Trace Coverage Analysis

Answers coverage questions from an S32DS Flat Profiler export using three local inputs: the .flatprofiler file, the ELF binary (with DWARF debug info), and the project source tree.

When to use

Trigger this skill when the user wants to:

• load a .flatprofiler + ELF + source tree and get a coverage overview
• find which functions were never executed or are only partially covered
• identify which source lines were not reached during the test run
• rank functions by execution time (flat profile hotspot view)
• view a source snippet annotated with per-line coverage state and hit counts
• understand inline function coverage (multiple instances at different addresses)
• answer "what percentage of my code ran?"

Do not use this skill to configure S32Trace (use s32trace-create-configuration), compile or flash firmware, or start a debug session.

Available Capabilities

Type	Name	Purpose
MCP tool	search_actions	discover available actions, their input schemas, and descriptions
MCP tool	execute_action	validated dispatcher -- pass action_name + action-specific params

All coverage operations are routed through execute_action:

Action name	Required params	Optional params
coverage.load	flatprofiler_path, elf_path, source_root	extra_source_roots, label, snippet_window
coverage.summary	session_id	core, top_k, include_no_source_info
coverage.function	session_id, name	core, include_source_rows
coverage.file	session_id, file_hint	core
coverage.uncovered	session_id	granularity (function/line/asm), sort_by, top_k, core, include_no_source_info
coverage.hotspots	session_id	sort_by, granularity (function/line), top_k, core, include_no_source_info
coverage.get_source	session_id	symbol, file_hint, line, core, snippet_window

Call search_actions first (or with a focused query such as "coverage load") to get the full parameter documentation before calling execute_action.

Typical workflow

coverage.load          -> returns session_id + load summary
  -> coverage.summary   (overview: coverage %, uncovered count, hotspots)
  -> coverage.function  (per-function detail + per-line breakdown)
  -> coverage.file      (file-level stats + uncovered function list)
  -> coverage.uncovered (ranked list of uncovered functions/lines/asm)
  -> coverage.hotspots  (most-executed functions or lines by time)
  -> coverage.get_source (source snippet annotated with coverage + time)

Quickstart

1. Call search_actions(query="coverage load") to confirm the action name and input schema.
2. Ask the user for the .flatprofiler, ELF, and source root paths.
3. Call execute_action(action_name="coverage.load", params={...}). Record session_id from the result -- it is required by every subsequent call.
4. Unless the user has a specific question, call execute_action(action_name="coverage.summary", params={"session_id": ...}) and present overall.asm_coverage_pct, overall.src_coverage_pct, function counts, top_by_time, and top_uncovered_by_size.
5. Answer follow-up questions using the action table above.

Workflow

1. Identify inputs. Confirm from the user:

   • Absolute path to the .flatprofiler file (flatprofiler_path). Typically at <workspace>/.AnalysisData/<session>/<name>.flatprofiler.
   • Absolute path to the ELF with DWARF debug info (elf_path). Must be the exact binary that was profiled.
   • Absolute path to the project source root (source_root). Needed for coverage.get_source to return annotated source text.

2. Load the coverage session. Call:

   execute_action(
     action_name = "coverage.load",
     params = {
       "flatprofiler_path": "<absolute path to .flatprofiler>",
       "elf_path":          "<absolute path to .elf>",
       "source_root":       "<absolute path to project src/>",
       "label":             "my_coverage_session"
     }
   )
   

   Verify: file_count > 0, function_count > 0, source.available: true. If source.available is false and the user supplied a source root, report the path as unresolved and offer to retry with a corrected path.

3. Get an overview. Call coverage.summary unless the user has a precise question. Key fields to present:

   • overall.asm_coverage_pct and overall.src_coverage_pct
   • overall.fully_covered_functions, overall.partially_covered_functions, overall.fully_uncovered_functions
   • top_uncovered_by_size -- the largest functions never executed
   • top_by_time -- where the CPU spent the most time

4. Answer specific questions.

   User question	Action to call	Key params
   "What is my overall coverage?"	coverage.summary	top_k
   "How much of slow_path.c is covered?"	coverage.file	file_hint="slow_path.c"
   "Show me coverage for slow_leaf"	coverage.function	name="slow_leaf"
   "Which functions were never executed?"	coverage.uncovered	granularity="function"
   "Show me uncovered lines in workloads.c"	coverage.uncovered	granularity="line"
   "Where does the CPU spend most of its time?"	coverage.hotspots	sort_by="time"
   "Show me main with coverage annotation"	coverage.get_source	symbol="main"
   "Show me the code around line 42 of main.c"	coverage.get_source	file_hint="main.c", line=42

5. Inline function handling. The S32DS profiler reports inlined functions at multiple addresses under names like clamp_i32_0x33d83d24. When the user asks about clamp_i32:

   1. Call coverage.uncovered or coverage.summary to see all instances listed.
   2. Call coverage.function with the exact mangled name for detail on a specific instance.
   3. Note that different instances may have different coverage because they are separate copies of the inlined code placed at different call sites.

6. Suggest improvements. When the user asks "what code should I test?" or "why is coverage low?":

   1. Call coverage.uncovered granularity=function -- rank by size to find the most impactful untested functions.
   2. Call coverage.file on each low-coverage source file to identify the uncovered functions.
   3. Call coverage.function with include_source_rows=true for partially-covered functions to see which branches/lines were missed.
   4. Call coverage.get_source to view the actual uncovered code.
   5. Present a prioritized list of specific test-gap recommendations with file + line references.

Guardrails

Scope

• All coverage actions are read-only; no file is written, no project is modified, and no S32 Design Studio process is started.
• Do not call configurator actions (configurator.*) from this skill.

Destructive actions

• None. coverage.load writes only to an in-memory session cache keyed by session_id; it does not touch any file.

Secrets

• No secrets or PII are involved; no redaction required.

Refuse-and-escalate

• coverage.load returns error: report the message verbatim and ask the user to verify the file paths.
• source.available is false after load: source paths in the .flatprofiler do not match the local tree; ask the user for the correct source_root or extra_source_roots.
• coverage.function returns found: false: confirm the exact symbol name using coverage.uncovered first.
• Path escape: coverage.get_source will refuse to read files outside the declared source roots; do not attempt to bypass this by constructing absolute paths that leave the root.
• Stale session_id: if an action returns "Coverage session ... not found", the MCP server was restarted; call coverage.load again and record the new session_id.

Resource limits

• Default top_k for uncovered is 20 and for hotspots is 10. Increase only when the user explicitly asks for more; never return unbounded results.
• get_source hard-limits snippets to 50 lines regardless of snippet_window.

_No source info bucket

• Functions with no DWARF source info (libc, newlib, startup, semihosting stubs) are grouped under _No source info and excluded from all aggregate queries by default. Set include_no_source_info=true to include them. Never include them unless the user explicitly asks about libc or runtime coverage.

Validation loop

1. After coverage.load, verify file_count > 0, function_count > 0, and (when source_root was given) source.available: true.
2. After coverage.summary, confirm overall.total_functions > 0.
3. Pass criterion: session_id is in hand and the load summary matches the user's expectations (correct core, function count, source available).

Out of scope

• Creating or editing S32Trace configuration XML (use s32trace-create-configuration).
• Trace event analysis from a decoded CSV (use s32trace-analyze-trace).
• Installing or updating S32 Design Studio.
• Compiling, flashing, or debugging firmware.
• Generating code from a .mex file (use s32ct-generate-code).

See Also

• search_actions(query="coverage") -- returns the full parameter schema for all 7 coverage.* actions.
• s32trace-analyze-trace -- sibling skill for trace event / timing analysis.
• s32trace-create-configuration -- skill for configuring the trace capture.