add support for in-source breakpoints (#133)

* add support for in source breakpoints

* ssa fixes

* simpler implementation

Author: KristofferC

docs/src/dev_reference.md

@@ -55,6 +55,7 @@ JuliaInterpreter.debug_command
 
 ```@docs
 @breakpoint
+@bp
 breakpoint
 enable
 disable

src/JuliaInterpreter.jl

@@ -14,7 +14,7 @@ using CodeTracking
 
 export @interpret, Compiled, Frame, root, leaf,
        BreakpointRef, breakpoint, @breakpoint, breakpoints, enable, disable, remove,
-       debug_command
+       debug_command, @bp
 
 module CompiledCalls
 # This module is for handling intrinsics that must be compiled (llvmcall)

src/breakpoints.jl

@@ -286,3 +286,14 @@ macro breakpoint(call_expr, args...)
         end
     end
 end
+
+const __BREAKPOINT_MARKER__ = nothing
+
+"""
+    @bp
+
+Insert a breakpoint at a location in the source code.
+"""
+macro bp()
+    return esc(:($(JuliaInterpreter).__BREAKPOINT_MARKER__))
+end

src/types.jl

@@ -64,6 +64,7 @@ struct FrameCode
     generator::Bool   # true if this is for the expression-generator of a @generated function
 end
 
+const BREAKPOINT_EXPR = :($(QuoteNode(getproperty))($JuliaInterpreter, :__BREAKPOINT_MARKER__))
 function FrameCode(scope, src::CodeInfo; generator=false, optimize=true)
     if optimize
         src, methodtables = optimize!(copy_codeinfo(src), moduleof(scope))
@@ -72,6 +73,12 @@ function FrameCode(scope, src::CodeInfo; generator=false, optimize=true)
         methodtables = Vector{Union{Compiled,TypeMapEntry}}(undef, length(src.code))
     end
     breakpoints = Vector{BreakpointState}(undef, length(src.code))
+    for (i, pc_expr) in enumerate(src.code)
+        if pc_expr == BREAKPOINT_EXPR
+            breakpoints[i] = BreakpointState()
+            src.code[i] = nothing
+        end
+    end
     used = find_used(src)
     return FrameCode(scope, src, methodtables, breakpoints, used, generator)
 end

test/breakpoints.jl

@@ -173,6 +173,20 @@ end
     bp = JuliaInterpreter.BreakpointRef(frame.framecode, 1, ArgumentError("whoops"))
     show(io, bp)
     @test String(take!(io)) == "breakpoint(loop_radius2(n) in $(@__MODULE__) at $(@__FILE__):3, line 3, ArgumentError(\"whoops\"))"
+
+    # In source breakpointing
+    f_outer_bp(x) = g_inner_bp(x)
+    function g_inner_bp(x)
+        sin(x)
+        @bp
+        @bp
+        @bp
+        x = 3
+        return 2
+    end
+    fr, bp = @interpret f_outer_bp(3)
+    @test leaf(fr).framecode.scope.name == :g_inner_bp
+    @test bp.stmtidx == 3
 end
 
 if tmppath != ""

test/debug.jl

@@ -232,6 +232,38 @@ struct B{T} end
         finally
             JuliaInterpreter.break_on_error[] = false
         end
-    end
 
+        @testset "breakpoints" begin
+            # In source breakpoints
+            function f_bp(x)
+                #=1=#    i = 1
+                #=2=#    @label foo
+                #=3=#    @bp
+                #=4=#    repr("foo")
+                #=5=#    i += 1
+                #=6=#    i > 3 && return x
+                #=7=#    @goto foo
+            end
+            ln = @__LINE__
+            method_start = ln - 9
+            fr = enter_call(f_bp, 2)
+            @test JuliaInterpreter.linenumber(fr) == method_start + 1
+            fr, pc =  JuliaInterpreter.debug_command(fr, "c")
+            # Hit the breakpoint x1
+            @test JuliaInterpreter.linenumber(fr) == method_start + 3
+            @test pc isa BreakpointRef
+            fr, pc =  JuliaInterpreter.debug_command(fr, "n")
+            @test JuliaInterpreter.linenumber(fr) == method_start + 4
+            fr, pc =  JuliaInterpreter.debug_command(fr, "c")
+            # Hit the breakpoint again x2
+            @test pc isa BreakpointRef
+            @test JuliaInterpreter.linenumber(fr) == method_start + 3
+            fr, pc =  JuliaInterpreter.debug_command(fr, "c")
+            # Hit the breakpoint for the last time x3
+            @test pc isa BreakpointRef
+            @test JuliaInterpreter.linenumber(fr) == method_start + 3
+            JuliaInterpreter.debug_command(fr, "c")
+            @test get_return(fr) == 2
+        end
+    end
 # end