Profile: add line number correction (Revise) (#34235)

This ensures that Profiling will report the current line number in 
interactively-modified code.

Author: timholy

stdlib/Profile/src/Profile.jl

@@ -196,9 +196,16 @@ function retrieve()
 end
 
 function getdict(data::Vector{UInt})
+    # Lookup is expensive, so do it only once per ip.
+    udata = unique(data)
     dict = LineInfoDict()
-    for ip in data
-        get!(() -> lookup(convert(Ptr{Cvoid}, ip)), dict, UInt64(ip))
+    for ip in udata
+        st = lookup(convert(Ptr{Cvoid}, ip))
+        # To correct line numbers for moving code, put it in the form expected by
+        # Base.update_stackframes_callback[]
+        stn = map(x->(x, 1), st)
+        try Base.invokelatest(Base.update_stackframes_callback[], stn) catch end
+        dict[UInt64(ip)] = map(first, stn)
     end
     return dict
 end

stdlib/Profile/test/runtests.jl

@@ -93,3 +93,21 @@ end
     @test delay_ == 0.0005
     Profile.init(n=1_000_000, delay=def_delay)
 end
+
+@testset "Line number correction" begin
+    @profile busywait(1, 20)
+    _, fdict0 = Profile.flatten(Profile.retrieve()...)
+    Base.update_stackframes_callback[] = function(list)
+        modify((sf, n)) = sf.func == :busywait ? (StackTraces.StackFrame(sf.func, sf.file, sf.line+2, sf.linfo, sf.from_c, sf.inlined, sf.pointer), n) : (sf, n)
+        map!(modify, list, list)
+    end
+    _, fdictc = Profile.flatten(Profile.retrieve()...)
+    Base.update_stackframes_callback[] = identity
+    function getline(sfs)
+        for sf in sfs
+            sf.func == :busywait && return sf.line
+        end
+        nothing
+    end
+    @test getline(values(fdictc)) == getline(values(fdict0)) + 2
+end

test/errorshow.jl

@@ -596,6 +596,26 @@ end
     end
 end
 
+@testset "Line number correction" begin
+    getbt() = backtrace()
+    bt = getbt()
+    Base.update_stackframes_callback[] = function(list)
+        modify((sf, n)) = sf.func == :getbt ? (StackTraces.StackFrame(sf.func, sf.file, sf.line+2, sf.linfo, sf.from_c, sf.inlined, sf.pointer), n) : (sf, n)
+        map!(modify, list, list)
+    end
+    io = IOBuffer()
+    Base.show_backtrace(io, bt)
+    outputc = split(String(take!(io)), '\n')
+    Base.update_stackframes_callback[] = identity
+    Base.show_backtrace(io, bt)
+    output0 = split(String(take!(io)), '\n')
+    function getline(output)
+        idx = findfirst(str->occursin("getbt", str), output)
+        return parse(Int, match(r":(\d*)$", output[idx]).captures[1])
+    end
+    @test getline(outputc) == getline(output0) + 2
+end
+
 # issue #30633
 @test_throws ArgumentError("invalid index: \"foo\" of type String") [1]["foo"]
 @test_throws ArgumentError("invalid index: nothing of type Nothing") [1][nothing]