Return type in derived functions

src/interface.jl

@@ -48,7 +48,7 @@
 end
 
 function is_already_linted(l::LintResult, filename)
     return filename in l.linted_files
 end
 
 function has_values(l::LintResult, a, b, c)
@@ -196,7 +196,7 @@
         this_annotation = annotation_for_this_line(line)
         # current_codepoint + sizeof(line) is possibly pointing at the newline that isn't
         # actually stored in `line`.
         if offset in current_codepoint:(current_codepoint + sizeof(line))
             index_in_line = offset - current_codepoint + 1 # possibly off the end by 1.
             if !isnothing(this_annotation)
                 annotation = this_annotation
@@ -276,7 +276,7 @@
     # Filter along the file content
     ss = split(hint_as_string)
     has_filename = isfile(last(ss))
     has_filename || error("Should have a filename")
 
     filename = string(last(ss))
 
@@ -463,7 +463,7 @@
     end
 
     # If already linted, then we merely exit
     rootpath in result.linted_files && return result
 
     # If we are running Lint on a directory
     isdir(rootpath) && return _run_lint_on_dir(rootpath; result, server, io, io_violations, io_recommendations, filters, formatter)
@@ -484,7 +484,7 @@
 
         # We are now reaching a bug HERE
         if isnothing(r)
-            @error "BUG FOUND IN StaticLint.jl, message from hint $(m) cannot be extracted"
+            @error "BUG FOUND IN StaticLint.jl, message from hint: $(m) cannot be extracted"
             return "ERROR"
         end
 

src/linting/extended_checks.jl

@@ -55,7 +55,7 @@
     !is_there_any_star_marker && return x == y
 
     contains(x, "QQQ") && contains(y, "QQQ") &&
         throw(BothCannotHaveStarException("Cannot both $x and $y have a star marker"))
     if contains(x, "QQQ")
         reg_exp = Regex(replace(x, "QQQ" => ".*"))
         return !isnothing(match(reg_exp, y))
@@ -212,6 +212,7 @@
 struct NonFrontShapeAPIUsage_Extension <: ViolationExtendedRule end
 struct InterpolationInSafeLog_Extension <: RecommendationExtendedRule end
 struct UseOfStaticThreads <: ViolationExtendedRule end
+struct ReturnTypeInDerived <: ViolationExtendedRule end
 
 
 const all_extended_rule_types = Ref{Any}(
@@ -268,7 +269,7 @@
 
 function get_recommendation(msg_prefix)
     m = retrieve_full_msg_from_prefix(msg_prefix)
     m in keys(is_recommendation) || return nothing
     return is_recommendation[m]
 end
 
@@ -311,7 +312,7 @@
 end
 
 function check_for_recommendation(T::DataType, msg::String)
     @assert supertype(T) in [RecommendationExtendedRule, ViolationExtendedRule]
     b = supertype(T) == RecommendationExtendedRule
     get!(is_recommendation, msg, b)
     return nothing
@@ -343,7 +344,7 @@
 
 function check(t::NThreads_Extention, x::EXPR, markers::Dict{Symbol,String})
     # Threads.nthreads() must not be used in a const field, but it is allowed elsewhere
     haskey(markers, :const) || return
     generic_check(t, x, "Threads.nthreads()", "`Threads.nthreads()` should not be used in a constant variable.")
 end
 
@@ -397,10 +398,10 @@
 check(t::Ptr_Extension, x::EXPR) = generic_check(t, x, "Ptr{hole_variable}(hole_variable)")
 
 function check(t::ArrayWithNoType_Extension, x::EXPR, markers::Dict{Symbol,String})
     haskey(markers, :filename) || return
     contains(markers[:filename], "src/Compiler") || return
 
     haskey(markers, :macrocall) && markers[:macrocall] == "@match" && return
     haskey(markers, :macrocall) && markers[:macrocall] == "@matchrule" && return
 
     generic_check(t, x, "[]", "Need a specific Array type to be provided.")
@@ -574,4 +575,10 @@
     msg = "Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`. Static threads must not be used as generated tasks will not be able to migrate across threads."
     generic_check(t, x, "@threads :static hole_variable_star", msg)
     generic_check(t, x, "Threads.@threads :static hole_variable_star", msg)
+end
+
+function check(t::ReturnTypeInDerived, x::EXPR, markers::Dict{Symbol,String})
+    msg = "Return type necessary in `@derived` functions."
+    generic_check(t, x, "@derived hole_variable function hole_variable(hole_variable_star) hole_variable_star end", msg)
+    generic_check(t, x, "@derived function hole_variable(hole_variable_star) hole_variable_star end", msg)
 end

test/rai_rules_tests.jl

@@ -1988,3 +1988,50 @@ end
     @test lint_test(source, "Line 2, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
     @test lint_test(source, "Line 6, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
 end
+
+@testset "Return type in derived functions" begin
+    @testset "No error" begin
+        source = """
+            @derived v=10 function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )::PhaseResult
+
+                return nothing
+            end
+            """
+        @test !lint_has_error_test(source)
+        # @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+    @testset "With error 01" begin
+        source = """
+            @derived v=10 function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )
+
+                return nothing
+            end
+            """
+        @test lint_has_error_test(source)
+        @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+
+    @testset "With error 02" begin
+        source = """
+            @derived function PhaseAPI.generated_defs_for_id(
+                rt::Runtime,
+                path::RelPath,
+                phase::PhaseNormalization,
+            )
+
+                return nothing
+            end
+            """
+        @test lint_has_error_test(source)
+        @test lint_test(source, "Line 1, column 1: Return type necessary in `@derived` functions.")
+    end
+end
+