aviatesk/JET.jl

# JET.jl [](https://aviatesk.github.io/JET.jl/dev/) [](https://github.com/aviatesk/JET.jl/actions/workflows/ci.yml) [](https://codecov.io/gh/aviatesk/JET.jl) [](https://github.com/aviatesk/JET.jl) JET 采用 Julia 的类型推断系统来检测潜在的错误和类型不稳定性。 ## 快速开始 请在[文档](https://aviatesk.github.io/JET.jl/dev/)中查看更多命令、选项和说明。 ### 安装 JET 是一个标准的 Julia 包。 因此，你可以直接通过 Julia 内置的包管理器进行安装，并像使用其他任何包一样使用它： ``` julia> using Pkg; Pkg.add("JET") [ some output elided ] julia> using JET ``` ### 使用 `@report_opt` 检测类型不稳定性 使用 `@report_opt` 宏可以在函数调用中检测类型不稳定性，其工作原理与 `@code_warntype` 宏类似。 请注意，因为 JET 依赖于 Julia 的类型推断，如果推断链由于动态分发而中断，那么编译器将无法获知所有后续的函数调用，因此 JET 无法对其进行分析。 ``` julia> @report_opt foldl(+, Any[]; init=0) ═════ 2 possible errors found ═════ ┌ kwcall(::@NamedTuple{init::Int64}, ::typeof(foldl), op::typeof(+), itr::Vector{Any}) @ Base ./reduce.jl:198 │┌ foldl(op::typeof(+), itr::Vector{Any}; kw::@Kwargs{init::Int64}) @ Base ./reduce.jl:198 ││┌ kwcall(::@NamedTuple{init::Int64}, ::typeof(mapfoldl), f::typeof(identity), op::typeof(+), itr::Vector{Any}) @ Base ./reduce.jl:175 │││┌ mapfoldl(f::typeof(identity), op::typeof(+), itr::Vector{Any}; init::Int64) @ Base ./reduce.jl:175 ││││┌ mapfoldl_impl(f::typeof(identity), op::typeof(+), nt::Int64, itr::Vector{Any}) @ Base ./reduce.jl:44 │││││┌ foldl_impl(op::Base.BottomRF{typeof(+)}, nt::Int64, itr::Vector{Any}) @ Base ./reduce.jl:48 ││││││┌ _foldl_impl(op::Base.BottomRF{typeof(+)}, init::Int64, itr::Vector{Any}) @ Base ./reduce.jl:58 │││││││┌ (::Base.BottomRF{typeof(+)})(acc::Int64, x::Any) @ Base ./reduce.jl:86 ││││││││ runtime dispatch detected: +(acc::Int64, x::Any)::Any │││││││└──────────────────── ││││││┌ _foldl_impl(op::Base.BottomRF{typeof(+)}, init::Int64, itr::Vector{Any}) @ Base ./reduce.jl:62 │││││││┌ (::Base.BottomRF{typeof(+)})(acc::Any, x::Any) @ Base ./reduce.jl:86 ││││││││ runtime dispatch detected: +(acc::Any, x::Any)::Any │││││││└──────────────────── ``` ### 使用 `@report_call` 检测类型错误 这在类型稳定的代码上效果最好，因此在使用 `@report_call` 之前，请尽量先使用 `@report_opt`。 ``` julia> @report_call foldl(+, Char[]) ═════ 2 possible errors found ═════ ┌ foldl(op::typeof(+), itr::Vector{Char}) @ Base ./reduce.jl:198 │┌ foldl(op::typeof(+), itr::Vector{Char}; kw::@Kwargs{}) @ Base ./reduce.jl:198 ││┌ mapfoldl(f::typeof(identity), op::typeof(+), itr::Vector{Char}) @ Base ./reduce.jl:175 │││┌ mapfoldl(f::typeof(identity), op::typeof(+), itr::Vector{Char}; init::Base._InitialValue) @ Base ./reduce.jl:175 ││││┌ mapfoldl_impl(f::typeof(identity), op::typeof(+), nt::Base._InitialValue, itr::Vector{Char}) @ Base ./reduce.jl:44 │││││┌ foldl_impl(op::Base.BottomRF{typeof(+)}, nt::Base._InitialValue, itr::Vector{Char}) @ Base ./reduce.jl:48 ││││││┌ _foldl_impl(op::Base.BottomRF{typeof(+)}, init::Base._InitialValue, itr::Vector{Char}) @ Base ./reduce.jl:62 │││││││┌ (::Base.BottomRF{typeof(+)})(acc::Char, x::Char) @ Base ./reduce.jl:86 ││││││││ no matching method found `+(::Char, ::Char)`: (op::Base.BottomRF{typeof(+)}).rf::typeof(+)(acc::Char, x::Char) │││││││└──────────────────── │││││┌ foldl_impl(op::Base.BottomRF{typeof(+)}, nt::Base._InitialValue, itr::Vector{Char}) @ Base ./reduce.jl:49 ││││││┌ reduce_empty_iter(op::Base.BottomRF{typeof(+)}, itr::Vector{Char}) @ Base ./reduce.jl:383 │││││││┌ reduce_empty_iter(op::Base.BottomRF{typeof(+)}, itr::Vector{Char}, ::Base.HasEltype) @ Base ./reduce.jl:384 ││││││││┌ reduce_empty(op::Base.BottomRF{typeof(+)}, ::Type{Char}) @ Base ./reduce.jl:360 │││││││││┌ reduce_empty(::typeof(+), ::Type{Char}) @ Base ./reduce.jl:343 ││││││││││ no matching method found `zero(::Type{Char})`: zero(T::Type{Char}) │││││││││└──────────────────── ``` ### 使用 `report_package` 分析包 它会查找所有方法定义，并根据其签名分析函数调用。请注意，这不如 `@report_call` 准确，因为对于泛型方法来说，实际的输入类型是未知的。 ``` julia> using Pkg; Pkg.activate(; temp=true, io=devnull); Pkg.add("AbstractTrees"; io=devnull); julia> Pkg.status() Status `/private/var/folders/xh/6zzly9vx71v05_y67nm_s9_c0000gn/T/jl_h07K2m/Project.toml` [1520ce14] AbstractTrees v0.4.5 julia> using AbstractTrees julia> report_package(AbstractTrees) [toplevel-info] Analyzing top-level definition (progress: 256/256) [toplevel-info] Analyzed all top-level definitions (all: 256 | analyzed: 256 | cached: 0 | took: 7.116 sec) [ Info: tracking Base ═════ 7 possible errors found ═════ ┌ isroot(root::Any, x::Any) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/base.jl:102 │ no matching method found `parent(::Any, ::Any)`: AbstractTrees.parent(root::Any, x::Any) └──────────────────── ┌ StableNode{T}(x::T, ch::Any) where T @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/base.jl:260 │┌ collect(::Type{StableNode{_A}} where _A, itr::Any) @ Base ./array.jl:641 ││┌ _collect(::Type{StableNode{_A}}, itr::Any, isz::Union{Base.HasLength, Base.HasShape}) where _A @ Base ./array.jl:643 │││┌ _array_for(::Type{StableNode{_A}} where _A, itr::Base.HasLength, isz::Any) @ Base ./array.jl:673 ││││┌ _similar_shape(itr::Base.HasLength, ::Base.HasLength) @ Base ./array.jl:657 │││││ no matching method found `length(::Base.HasLength)`: length(itr::Base.HasLength) ││││└──────────────────── ││││┌ _similar_shape(itr::Base.HasLength, ::Base.HasShape) @ Base ./array.jl:658 │││││┌ axes(A::Base.HasLength) @ Base ./abstractarray.jl:98 ││││││ no matching method found `size(::Base.HasLength)`: size(A::Base.HasLength) │││││└──────────────────── ┌ IndexNode(tree::Any) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:117 │ no matching method found `rootindex(::Any)`: rootindex(tree::Any) └──────────────────── ┌ parent(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:127 │ no matching method found `parentindex(::Any, ::Any)`: pidx = parentindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── ┌ nextsibling(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:132 │ no matching method found `nextsiblingindex(::Any, ::Any)`: sidx = nextsiblingindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── ┌ prevsibling(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:137 │ no matching method found `prevsiblingindex(::Any, ::Any)`: sidx = prevsiblingindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── julia> report_package(AbstractTrees; target_modules=(AbstractTrees,)) # ignore errors that occur outside the AbstractTrees module context [toplevel-info] Skipped analysis for cached definition (256/256) [toplevel-info] Analyzed all top-level definitions (all: 256 | analyzed: 0 | cached: 256 | took: 0.036 sec) ═════ 5 possible errors found ═════ ┌ isroot(root::Any, x::Any) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/base.jl:102 │ no matching method found `parent(::Any, ::Any)`: AbstractTrees.parent(root::Any, x::Any) └──────────────────── ┌ IndexNode(tree::Any) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:117 │ no matching method found `rootindex(::Any)`: rootindex(tree::Any) └──────────────────── ┌ parent(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:127 │ no matching method found `parentindex(::Any, ::Any)`: pidx = parentindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── ┌ nextsibling(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:132 │ no matching method found `nextsiblingindex(::Any, ::Any)`: sidx = nextsiblingindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── ┌ prevsibling(idx::IndexNode) @ AbstractTrees /Users/aviatesk/.julia/packages/AbstractTrees/Ftf8W/src/indexing.jl:137 │ no matching method found `prevsiblingindex(::Any, ::Any)`: sidx = prevsiblingindex((idx::IndexNode).tree::Any, (idx::IndexNode).index::Any) └──────────────────── ``` ## 局限性 JET 会探索你直接调用的函数以及它们*可推断的*被调用者。然而，如果某次调用的参数类型无法推断，JET 将不会分析该被调用者。因此，报告 `No errors detected` 并不意味着你的整个代码库都没有错误。为了提高对 JET 结果的可信度，请使用 `@report_opt` 确保你的代码是可推断的。