Merge pull request #105 from nystrom/master

Add `@cond` command

README.md

@@ -131,7 +131,7 @@ julia> function f(x)
        end
 f (generic function with 1 method)
 
-julia> f([1,2,3])
+julia> f([1,2,3,4,5,6,7,8,9,10])
 Infiltrating f(x::Vector{Int64})
   at REPL[10]:5
 
@@ -152,6 +152,9 @@ infil> ?
 
     •  @toggle: Toggle infiltrating at this @infiltrate spot (clear all with Infiltrator.clear_disabled!()).
 
+    •  @cond expr: Infiltrate at this @infiltrate spot only if <expr> evaluates to true (clear all with
+       Infiltrator.clear_conditions!()).
+
     •  @continue: Continue to the next infiltration point or exit (shortcut: Ctrl-D).
 
     •  @doc symbol: Get help for symbol (same as in the normal Julia REPL).
@@ -161,7 +164,7 @@ infil> ?
 infil> @locals
 - out::Vector{Any} = Any[2]
 - i::Int64 = 1
-- x::Vector{Int64} = [1, 2, 3]
+- x::Vector{Int64} = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
 
 infil> 0//0
 ERROR: ArgumentError: invalid rational: zero(Int64)//zero(Int64)
@@ -183,38 +186,64 @@ Disabled infiltration at this infiltration point.
 infil> @toggle
 Enabled infiltration at this infiltration point.
 
+infil> @cond i > 5
+Conditionally enabled infiltration at this infiltration point.
+
 infil> @continue
 
 Infiltrating f(x::Vector{Int64})
   at REPL[10]:5
 
+infil> i
+6
+
 infil> intermediate = copy(out)
-2-element Vector{Any}:
- 2
- 4
+6-element Vector{Any}:
+  2
+  4
+  6
+  8
+ 10
+ 12
 
 infil> @exfiltrate intermediate x
 Exfiltrating 2 local variables into the safehouse.
 
 infil> @exit
 
-3-element Vector{Any}:
- 2
- 4
- 6
+10-element Vector{Any}:
+  2
+  4
+  6
+  8
+ 10
+ 12
+ 14
+ 16
+ 18
+ 20
+
 
 julia> safehouse.intermediate
-2-element Vector{Any}:
- 2
- 4
+6-element Vector{Any}:
+  2
+  4
+  6
+  8
+ 10
+ 12
 
 julia> @withstore begin
          x = 23
          x .* intermediate
        end
-2-element Vector{Int64}:
- 46
- 92
+6-element Vector{Int64}:
+  46
+  92
+ 138
+ 184
+ 230
+ 276
 ```
 
 ## Related projects

src/Infiltrator.jl

@@ -128,6 +128,7 @@ mutable struct Session
   store::Module
   exiting::Bool
   disabled::Set
+  conditions::Dict
 end
 function Base.show(io::IO, s::Session)
   n = length(get_store_names(s))
@@ -166,7 +167,7 @@ Also see [`clear_store!`](@ref), [`set_store!`](@ref), and [`@withstore`](@ref)
 safehouse-related functionality.
 """
 @doc store_docstring
-const store = Session(Module(), false, Set())
+const store = Session(Module(), false, Set(), Dict())
 @doc store_docstring
 const safehouse = store
 @doc store_docstring
@@ -202,6 +203,16 @@ function clear_disabled!(s = store)
   return nothing
 end
 
+"""
+    clear_conditions!(s = safehouse)
+
+Clear all conditional infiltration points.
+"""
+function clear_conditions!(s = store)
+  empty!(getfield(s, :conditions))
+  return nothing
+end
+
 """
     end_session!(s = safehouse)
 
@@ -240,7 +251,12 @@ function start_prompt(mod, locals, file, fileline;
   lock(INFILTRATION_LOCK[])
   try
     getfield(store, :exiting) && return
-    (file, fileline) in getfield(store, :disabled) && return
+    spot = (file, fileline)
+    spot in getfield(store, :disabled) && return
+    cs = getfield(store, :conditions)
+    f = get(cs, spot, nothing)
+    # Use invokelatest because we may have added f before returning to the REPL.
+    isnothing(f) || Base.invokelatest(f, locals) || return
 
     if terminal === nothing || repl === nothing
       active_repl_backend = nothing
@@ -339,6 +355,7 @@ The following commands are special cased:
   - `@exfiltrate`: Save all local variables into the store. `@exfiltrate x y` saves `x` and `y`;
     this variant can also exfiltrate variables defined in the `infil>` REPL.
   - `@toggle`: Toggle infiltrating at this `@infiltrate` spot (clear all with `Infiltrator.clear_disabled!()`).
+  - `@cond expr`: Infiltrate at this `@infiltrate` spot only if `expr` evaluates to true (clear all with `Infiltrator.clear_conditions!()`). Only local variables can be accessed here.
   - `@continue`: Continue to the next infiltration point or exit (shortcut: Ctrl-D).
   - `@doc symbol`: Get help for `symbol` (same as in the normal Julia REPL).
   - `@exit`: Stop infiltrating for the remainder of this session and exit (on Julia versions prior to
@@ -505,15 +522,61 @@ function debugprompt(mod, locals, trace, terminal, repl, nostack = false; file,
       elseif sline == "@toggle"
         spot = (file, fileline)
         ds = getfield(store, :disabled)
+        cs = getfield(store, :conditions)
         if spot in ds
           delete!(ds, spot)
-          println(io, "Enabled infiltration at this infiltration point.\n")
+          if haskey(cs, spot)
+            println(io, "Conditionally enabled infiltration at this infiltration point.\n")
+          else
+            println(io, "Enabled infiltration at this infiltration point.\n")
+          end
         else
           push!(ds, spot)
           println(io, "Disabled infiltration at this infiltration point.\n")
         end
         LineEdit.reset_state(s)
         return true
+      elseif startswith(sline, "@cond")
+        spot = (file, fileline)
+        ds = getfield(store, :disabled)
+        cs = getfield(store, :conditions)
+        rest = lstrip(sline[6:end])
+
+        try
+          expr = Base.parse_input_line(rest)
+          @assert expr.head == :toplevel
+          # Unwrap the :toplevel node and replace with a :block
+          expr = Expr(:block, expr.args...)
+          # Wrap the expr in a closure.
+          # We need to gensym a new name to avoid this error:
+          #    cannot declare #1#2 constant; it already has a value
+          # Pass a locals dict into the function so we access the locals at the
+          # next infiltration point rather than capturing the locals here.
+          fname = gensym(:cond)
+          locals_dict = gensym(:locals)
+          expr = quote
+            function $(fname)($locals_dict)
+              $(
+                ( Expr(:(=), x, Expr(:ref, locals_dict, Expr(:call, Symbol, string(x))))
+                  for x in keys(locals)
+                )...
+              )
+              $(expr)
+            end
+            $fname
+          end
+          # Eval and save in the dict.
+          result = Core.eval(evalmod, expr)
+          cs[spot] = result
+          # Remove the spot from the disabled set.
+          delete!(ds, spot)
+          println(io, "Conditionally enabled infiltration at this infiltration point.\n")
+          LineEdit.reset_state(s)
+          return true
+        catch err
+          # If we get an error, just punt to the eval code to handle the error.
+          line = rest
+        end
       elseif sline == "@exit"
         setfield!(store, :exiting, true)
         if !REPL_HOOKED[]
@@ -726,7 +789,6 @@ end
 
 function interpret(expr, evalmod)
   out = Core.eval(evalmod, :(ans = $(expr)))
-
   return out
 end
 

test/fixtures/toplevel-fixture.jl

@@ -1,5 +1,7 @@
 using Infiltrator
-println(2+2)
+if VERSION > v"1.7"
+    println(2+2)
+end
 @infiltrate
 
 "success"

test/generate.jl

@@ -0,0 +1,4 @@
+for version in ["1.1", "1.6", "1.7", "1.8", "1.9", "1.10"]
+    println("Generating outputs with Julia v$version")
+    run(addenv(`julia +$version --project=$(dirname(@__DIR__)) -e 'using Pkg; Pkg.test()'`, "INFILTRATOR_CREATE_TEST" => 1))
+end