package wax-lib

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Libraries for Wax, a Rust-like syntax for WebAssembly

Install 

dune-project
 Dependency

github.com Readme Changelog Edit opam file Versions (1)

Authors

  1. J
    Jérôme Vouillon

Maintainers

  1. J
    Jérôme Vouillon

Sources

wax-0.1.0.tbz
sha256=41b580846af8d41bdf6c3f005f62e38feda3e60fe2e9e4aa440db34ce515a153
sha512=4b3a181fcc7d743194a8647260870fb5190770066a197bcc48104c2b77fd40c643228b795c2bcd6b29a120820e969eb42a37a9bcec98b3f608d13f152d9f6579

doc/wax-lib.utils/Wax_utils/Warning/index.html

Module Wax_utils.WarningSource

Named, groupable warnings whose reporting level is configurable.

Each diagnostic warning has a stable name (e.g. unused-local) and may belong to one or more groups (e.g. unused). A policy maps each warning to a level — hidden, displayed, or promoted to an error — so the same warning can be silenced, shown, or made fatal depending on the invocation (see the -W command-line option).

Sourcetype t =
  1. | Unused_local
    (*

    A local that is declared but never read.

    *)
  2. | Unused_field
    (*

    A module field (a function or global) that is defined but never referenced, exported, or used as the start function.

    *)
  3. | Unused_import
    (*

    An imported function or global that is never referenced, exported, or used as the start function.

    *)
  4. | Unused_label
    (*

    A block label that is declared but never branched to.

    *)
  5. | Shift_overflow
    (*

    A shift by a constant count at least as large as the operand's bit width; Wasm masks the count modulo the width, so the shift is almost certainly not what was meant.

    *)
  6. | Constant_trap
    (*

    An operation that always traps on a constant operand: an integer division or remainder by zero, or a trapping float-to-integer conversion of an out-of-range constant.

    *)
  7. | Tautological_comparison
    (*

    A comparison whose result is constant regardless of its variable operand: an unsigned comparison against zero, or a comparison of two identical operands.

    *)
  8. | Constant_condition
    (*

    A branch, loop, or select condition that is a constant, so it always (or never) takes the same path.

    *)
  9. | Unused_result
    (*

    The result of a side-effect-free expression is computed and then discarded (e.g. _ = x + 1).

    *)
  10. | Dead_code
    (*

    A statement that can never be reached because it follows an unconditional branch, return, or unreachable.

    *)
  11. | Cast_always_fails
    (*

    A reference cast or test whose operand can never have the target type (the two are unrelated in the type hierarchy), so the cast always traps and the test is always false.

    *)
  12. | Eager_select
    (*

    A trapping or effectful operation (an integer division, a field or element access, a !, a descriptor cast, a call, an assignment, …) appears in a branch of a ?:. Since ?: compiles to a select, which evaluates both branches, that operation runs even when the condition selects the other branch.

    *)
  13. | Precedence
    (*

    Two operators whose relative precedence is easy to misremember are mixed without parentheses: a shift (<</>>) with an arithmetic operator (+, -, *, …), or a comparison with a bitwise operator (&, |, ^). The code is correct, but a reader (especially one used to C's different table) may misread the grouping.

    *)
  14. | Redundant_operation
    (*

    An operation with no effect on its result: an arithmetic identity (x + 0, x * 1, x << 0, …), an absorbing operand (x * 0, x & 0), an operation on two identical operands (x - x, x ^ x, x & x), a self-assignment (x = x), or a cast to a type the operand already has.

    *)
  15. | Truncated_coverage
    (*

    Path-sensitive validation gave up after too many conditional configurations.

    *)
  16. | Naming_conflict
    (*

    Converting from Wasm, a source name collided with another and was renamed to a fresh one.

    *)
  17. | Reserved_word_rename
    (*

    Converting from Wasm, a source name is a Wax reserved word and was renamed to a fresh one.

    *)
  18. | Generated_name
    (*

    Converting from Wasm, an unnamed but referenced parameter was given a generated name (it cannot be rendered anonymously).

    *)
Sourceval all : t list

Every named warning.

Sourceval name : t -> string

The stable, hyphenated name of a warning (e.g. "unused-local").

Sourceval description : t -> string

A one-line human-readable description, used in help text.

Sourceval is_unnecessary : t -> bool

Whether the warning flags code that can be removed with no change in behaviour (an unused binding, import, or label, or unreachable code), so an editor can render it faded — LSP's DiagnosticTag.Unnecessary, VS Code's greyed-out dead code.

Levels and policies

Sourcetype level =
  1. | Hidden
    (*

    Suppress the warning entirely.

    *)
  2. | Displayed
    (*

    Report it as a warning (the default).

    *)
  3. | Error
    (*

    Promote it to an error (fails the run).

    *)
Sourcetype policy

A mapping from each warning to its level.

Sourceval default_policy : policy

The policy giving each warning its default level. Most warnings default to Displayed; the From_wasm renaming warnings (naming-conflict, reserved-word-rename) default to Hidden.

Sourceval resolve : policy -> t -> level

resolve policy w is the level configured for w.

Sourceval set : policy -> string -> level -> (policy, string) result

set policy name level returns policy updated so that the warning named name (or every warning in the group named name, including the special group "all") has level level. Returns Error msg if name matches no known warning or group. Later calls override earlier ones.

Sourceval parse_spec : string -> (string * level, string) result

parse_spec s parses a -W argument of the form NAME=LEVEL into its warning/group name and level. LEVEL is one of hidden, warning, or error. Returns Error msg on a malformed spec or unknown level.

Sourceval groups : string list

The names of the warning groups (excluding the special "all"), for help text.