methoddefs!: check signature equality (#46)

* methoddefs!: check signature equality

Formerly, our "noop" signature addition (which failed to advance pc) did
not check exact signature-equality in the manner of what had been
implicitly assumed to be a condition for this branch.
This "mostly-one-line" change fixes that.

Fixes timholy/Revise.jl#550
Fixes timholy/Revise.jl#547

* Make usage of CBinding conditional on Julia version

Author: timholy

Project.toml

@@ -1,7 +1,7 @@
 name = "LoweredCodeUtils"
 uuid = "6f1432cf-f94c-5a45-995e-cdbf5db27b0b"
 authors = ["Tim Holy <tim.holy@gmail.com>"]
-version = "1.2.2"
+version = "1.2.3"
 
 [deps]
 JuliaInterpreter = "aa1ae85d-cabe-5617-a682-6adf51b2e16a"
@@ -13,7 +13,8 @@ julia = "1"
 [extras]
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 Parameters = "d96e819e-fc66-5662-9728-84c9c7592b0a"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["InteractiveUtils", "Parameters", "Test"]
+test = ["InteractiveUtils", "Parameters", "Pkg", "Test"]

src/signatures.jl

@@ -441,22 +441,27 @@ function methoddef!(@nospecialize(recurse), signatures, frame::Frame, @nospecial
             pc = step_expr!(recurse, frame, stmt, true)
             meth = whichtt(sigt)
         end
-        if isa(meth, Method)
+        if isa(meth, Method) && (meth.sig <: sigt && sigt <: meth.sig)
             push!(signatures, meth.sig)
-        elseif arg1 === false || arg1 === nothing
-            # If it's anonymous and not defined, define it
-            pc = step_expr!(recurse, frame, stmt, true)
-            meth = whichtt(sigt)
-            isa(meth, Method) && push!(signatures, meth.sig)
-            return pc, pc3
         else
-            # guard against busted lookup, e.g., https://github.com/JuliaLang/julia/issues/31112
-            code = framecode.src
-            codeloc = codelocation(code, pc)
-            loc = linetable(code, codeloc)
-            ft = Base.unwrap_unionall((Base.unwrap_unionall(sigt)::DataType).parameters[1])
-            if !startswith(String(ft.name.name), "##")
-                @warn "file $(loc.file), line $(loc.line): no method found for $sigt"
+            if arg1 === false || arg1 === nothing
+                # If it's anonymous and not defined, define it
+                pc = step_expr!(recurse, frame, stmt, true)
+                meth = whichtt(sigt)
+                isa(meth, Method) && push!(signatures, meth.sig)
+                return pc, pc3
+            else
+                # guard against busted lookup, e.g., https://github.com/JuliaLang/julia/issues/31112
+                code = framecode.src
+                codeloc = codelocation(code, pc)
+                loc = linetable(code, codeloc)
+                ft = Base.unwrap_unionall((Base.unwrap_unionall(sigt)::DataType).parameters[1])
+                if !startswith(String(ft.name.name), "##")
+                    @warn "file $(loc.file), line $(loc.line): no method found for $sigt"
+                end
+                if pc == pc3
+                    pc = next_or_nothing!(frame)
+                end
             end
         end
         frame.pc = pc

test/signatures.jl

@@ -19,6 +19,20 @@ const LT{T} = Union{LVec{<:Any, T}, T}
 const FloatingTypes = Union{Float32, Float64}
 end
 
+# Stuff for https://github.com/timholy/Revise.jl/issues/550
+if Base.VERSION >= v"1.1"
+    try
+        using CBinding
+    catch
+        @info "Adding CBinding to the environment for test purposes"
+        using Pkg
+        Pkg.add("CBinding")    # not available for Julia 1.0
+    end
+    eval(:(module Lowering550
+    using CBinding
+    end))
+end
+
 bodymethtest0(x) = 0
 function bodymethtest0(x)
     y = 2x
@@ -371,6 +385,19 @@ bodymethtest5(x, y=Dict(1=>2)) = 5
     pc = methoddefs!(signatures, frame; define=false)
     @test typeof(Lowering422.fneg) ∈ Set(Base.unwrap_unionall(sig).parameters[1] for sig in signatures)
 
+    # https://github.com/timholy/Revise.jl/issues/550
+    if Base.VERSION >= v"1.1"
+        ex = :(@cstruct S {
+            val::Int8
+        })
+        empty!(signatures)
+        Core.eval(Lowering550, ex)
+        frame = Frame(Lowering550, ex)
+        rename_framemethods!(frame)
+        pc = methoddefs!(signatures, frame; define=false)
+        @test !isempty(signatures)   # really we just need to know that `methoddefs!` completed without getting stuck
+    end
+
     # Undefined names
     # This comes from FileWatching; WindowsRawSocket is only defined on Windows
     ex = quote