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Diffstat (limited to 'subx_debugging.md')
| -rw-r--r-- | subx_debugging.md | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/subx_debugging.md b/subx_debugging.md index d7c0c294..27b98774 100644 --- a/subx_debugging.md +++ b/subx_debugging.md @@ -25,20 +25,24 @@ rudimentary but hopefully still workable toolkit: - Generate a trace for the failing test while running your program in emulated mode (`bootstrap run`): + ``` $ ./bootstrap translate input.subx -o binary $ ./bootstrap --trace run binary arg1 arg2 2>trace ``` + The ability to generate a trace is the essential reason for the existence of `bootstrap run` mode. It gives far better visibility into program internals than running natively. - As a further refinement, it is possible to render label names in the trace by adding a second flag to the `bootstrap translate` command: + ``` $ ./bootstrap --debug translate input.subx -o binary $ ./bootstrap --trace run binary arg1 arg2 2>trace ``` + `bootstrap --debug translate` emits a mapping from label to address in a file called `labels`. `bootstrap --trace run` reads in the `labels` file if it exists and prints out any matching label name as it traces each instruction @@ -57,9 +61,11 @@ rudimentary but hopefully still workable toolkit: some loop. Function names get similar `run: == label` lines. - One trick when emitting traces with labels: + ``` $ grep label trace ``` + This is useful for quickly showing you the control flow for the run, and the function executing when the error occurred. I find it useful to start with this information, only looking at the complete trace after I've gotten |