driver: suggest the closest warning for an unknown -W name

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
72/100
Issue type
Feature
Clarity
Clearly specified
Activity status
Active
Tech stack
c
Domain
cli, compilers

Research direction

Read the unknown warning handling in src/driver/main.c around lines 7625 and 7729, then inspect warning enumeration in src/driver/diag.c and edit_distance() in src/sema/sema.c. Start with tests/golden/driver-wp.sh to see the current output. Add close and distant typo cases; done means the three specified misspellings suggest unused-variable, distant names get no suggestion, and the tests pass.

Written by the indexing model from the issue text.

Description

enhancement good first issue

Context. A misspelled warning is reported, but EmbCC does not say what was probably meant:

$ ./embcc -Wunused-vairable -c t.c
embcc: warning: -Wunused-vairable is not a warning EmbCC has, so it turns nothing on (--help-warnings lists them)

It should add did you mean -Wunused-variable?.

Where.

  • src/driver/main.c, around line 7729, where a -W or -Wno- name is looked up. Near line 7625 there is a second message of the same kind, for -Werror=NAME ("names no warning EmbCC has"); give it the suggestion too.
  • src/driver/diag.c, line 1068: diag_warning_count() and diag_warning_name(i) list every warning name.
  • src/sema/sema.c, line 2108: edit_distance(). It is static; share it with the driver instead of copying it. Another good first issue moves the same function, for --target=; whichever lands first, the other reuses it.
  • Tests: tests/golden/driver-wp.sh checks the current message.

Steps.

  1. For an unknown name, find the closest diag_warning_name(i). Suggest it only if it is within max(2, len / 3) edits.
  2. Add the suggestion to the warning, keeping the existing wording, so scripts that grep for it still match.
  3. Add cases to the test: one with a close typo, and one with a name far from every warning.

Done when -Wunused-vairable, -Wno-unused-vairable and -Werror=unused-vairable all suggest unused-variable, a far-off name suggests nothing, and the tests pass.

Before you start: the contributor's guide has the rules. A new test counts only after it has failed against the code before your change, and a commit subject reads area: summary. Questions are welcome in the comments or in Discussions.

Dominant language
C
Stars
1
Forks
2
Avg merge
20h 55m
Merged PRs (30d)
73

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