Revert API breaking name change lookupat->lookup from #33190

With return->call address tanslation done inside jl_unw_stepn, there
should largely be no need to make this API breaking change, as all
backtrace addresses which the user has access to will already be
translated and can be passed directly into `StackTraces.lookup()`, as
was done previously.

There's one possible exception to this rule: If the user were looking up
the debug info for a pointer to a C function *not* obtained from a
backtrace, they previously would have had to use
`StackTraces.lookup(ptr+1)` to "undo" the the `ptr-1` translation that
`StackTraces.lookup` used to perform prior to #33190.  This seems like
an edge case however and probably not worth breaking the API over.

base/client.jl

@@ -81,7 +81,7 @@ end
 
 # deprecated function--preserved for DocTests.jl
 function ip_matches_func(ip, func::Symbol)
-    for fr in StackTraces.lookupat(ip)
+    for fr in StackTraces.lookup(ip)
         if fr === StackTraces.UNKNOWN || fr.from_c
             return false
         end

base/deprecated.jl

@@ -102,7 +102,7 @@ function firstcaller(bt::Vector, funcsyms)
     # Identify the calling line
     found = false
     for ip in bt
-        lkups = StackTraces.lookupat(ip)
+        lkups = StackTraces.lookup(ip)
         for lkup in lkups
             if lkup == StackTraces.UNKNOWN || lkup.from_c
                 continue

base/errorshow.jl

@@ -612,7 +612,7 @@ function process_backtrace(t::Vector, limit::Int=typemax(Int); skipC = true)
         if lkups isa StackFrame
             lkups = [lkups]
         else
-            lkups = StackTraces.lookupat(lkups)
+            lkups = StackTraces.lookup(lkups)
         end
         for lkup in lkups
             if lkup === StackTraces.UNKNOWN

base/stacktraces.jl

@@ -73,7 +73,7 @@ An alias for `Vector{StackFrame}` provided for convenience; returned by calls to
 const StackTrace = Vector{StackFrame}
 
 const empty_sym = Symbol("")
-const UNKNOWN = StackFrame(empty_sym, empty_sym, -1, nothing, true, false, 0) # === lookupat(C_NULL)
+const UNKNOWN = StackFrame(empty_sym, empty_sym, -1, nothing, true, false, 0) # === lookup(C_NULL)
 
 
 #=
@@ -96,13 +96,13 @@ end
 
 
 """
-    lookupat(pointer::Ptr{Cvoid}) -> Vector{StackFrame}
+    lookup(pointer::Ptr{Cvoid}) -> Vector{StackFrame}
 
 Given a pointer to an execution context (usually generated by a call to `backtrace`), looks
 up stack frame context information. Returns an array of frame information for all functions
 inlined at that point, innermost function first.
 """
-function lookupat(pointer::Ptr{Cvoid})
+function lookup(pointer::Ptr{Cvoid})
     infos = ccall(:jl_lookup_code_address, Any, (Ptr{Cvoid}, Cint), pointer, false)
     pointer = convert(UInt64, pointer)
     isempty(infos) && return [StackFrame(empty_sym, empty_sym, -1, nothing, true, false, pointer)] # this is equal to UNKNOWN
@@ -117,7 +117,7 @@ end
 
 const top_level_scope_sym = Symbol("top-level scope")
 
-function lookupat(ip::Base.InterpreterIP)
+function lookup(ip::Base.InterpreterIP)
     if ip.code isa Core.MethodInstance && ip.code.def isa Method
         codeinfo = ip.code.uninferred
         func = ip.code.def.name
@@ -188,7 +188,7 @@ trace, `stacktrace` first calls `backtrace`.
 function stacktrace(trace::Vector{<:Union{Base.InterpreterIP,Ptr{Cvoid}}}, c_funcs::Bool=false)
     stack = StackTrace()
     for ip in trace
-        for frame in lookupat(ip)
+        for frame in lookup(ip)
             # Skip frames that come from C calls.
             if c_funcs || !frame.from_c
                 push!(stack, frame)

doc/src/base/stacktraces.md

@@ -7,9 +7,9 @@ Base.StackTraces.stacktrace
 ```
 
 The following methods and types in `Base.StackTraces` are not exported and need to be called e.g.
-as `StackTraces.lookupat(ptr)`.
+as `StackTraces.lookup(ptr)`.
 
 ```@docs
-Base.StackTraces.lookupat
+Base.StackTraces.lookup
 Base.StackTraces.remove_frames!
 ```

doc/src/manual/stacktraces.md

@@ -300,12 +300,12 @@ julia> stacktrace(trace, true)
 ```
 
 Individual pointers returned by [`backtrace`](@ref) can be translated into [`StackTraces.StackFrame`](@ref)
-s by passing them into [`StackTraces.lookupat`](@ref):
+s by passing them into [`StackTraces.lookup`](@ref):
 
 ```julia-repl
 julia> pointer = backtrace()[1];
 
-julia> frame = StackTraces.lookupat(pointer)
+julia> frame = StackTraces.lookup(pointer)
 1-element Array{Base.StackTraces.StackFrame,1}:
  jl_apply_generic at gf.c:2167
 

stdlib/Profile/src/Profile.jl

@@ -5,11 +5,10 @@ Profiling support, main entry point is the [`@profile`](@ref) macro.
 """
 module Profile
 
-import Base.StackTraces: lookupat, UNKNOWN, show_spec_linfo, StackFrame
+import Base.StackTraces: lookup, UNKNOWN, show_spec_linfo, StackFrame
 
 # deprecated functions: use `getdict` instead
-lookup(ip::UInt) = lookupat(convert(Ptr{Cvoid}, ip))
-lookup(ip::Ptr{Cvoid}) = lookupat(ip)
+lookup(ip::UInt) = lookup(convert(Ptr{Cvoid}, ip))
 
 export @profile
 

test/backtrace.jl

@@ -1,15 +1,15 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
-import StackTraces: lookupat
+import StackTraces: lookup
 
 # Test location information for inlined code (ref issues #1334 #12544)
 module test_inline_bt
 using Test
-import ..lookupat
+import ..lookup
 
 function get_bt_frames(functionname, bt)
     for i = 1:length(bt)
-        lkup = lookupat(bt[i])
+        lkup = lookup(bt[i])
         lkup[end].func == functionname && return lkup
     end
     return StackTraces.StackFrame[]
@@ -96,13 +96,13 @@ end
 
 module BackTraceTesting
 using Test
-import ..lookupat
+import ..lookup
 
 @inline bt2() = backtrace()
 @inline bt1() = bt2()
 bt() = bt1()
 
-lkup = map(lookupat, bt())
+lkup = map(lookup, bt())
 hasbt = hasbt2 = false
 for sfs in lkup
     for sf in sfs
@@ -121,7 +121,7 @@ function btmacro()
     ret = @timed backtrace()
     ret[1]
 end
-lkup = map(lookupat, btmacro())
+lkup = map(lookup, btmacro())
 hasme = hasbtmacro = false
 for sfs in lkup
     for sf in sfs
@@ -146,7 +146,7 @@ bt = eval(quote
         catch_backtrace()
     end
 end)
-lkup = map(lookupat, bt)
+lkup = map(lookup, bt)
 hastoplevel = false
 for sfs in lkup
     for sf in sfs
@@ -174,7 +174,7 @@ let bt, found = false
     @testset begin
         bt = backtrace()
     end
-    for frame in map(lookupat, bt)
+    for frame in map(lookup, bt)
         if frame[1].line == @__LINE__() - 3 && frame[1].file == Symbol(@__FILE__)
             found = true; break
         end
@@ -186,7 +186,7 @@ end
 let bt, found = false
     @info ""
     bt = backtrace()
-    for frame in map(lookupat, bt)
+    for frame in map(lookup, bt)
         if frame[1].line == @__LINE__() - 2 && frame[1].file == Symbol(@__FILE__)
             found = true; break
         end

test/compiler/inference.jl

@@ -894,7 +894,7 @@ function break_21369()
         i = 1
         local fr
         while true
-            fr = Base.StackTraces.lookupat(bt[i])[end]
+            fr = Base.StackTraces.lookup(bt[i])[end]
             if !fr.from_c && fr.func !== :error
                 break
             end

test/meta.jl

@@ -32,7 +32,7 @@ h_noinlined() = g_noinlined()
 
 function foundfunc(bt, funcname)
     for b in bt
-        for lkup in StackTraces.lookupat(b)
+        for lkup in StackTraces.lookup(b)
             if lkup.func == funcname
                 return true
             end

test/stacktraces.jl

@@ -48,7 +48,7 @@ let (default, with_c, without_c) = (stacktrace(), stacktrace(true), stacktrace(f
     @test isempty(filter(frame -> frame.from_c, without_c))
 end
 
-@test StackTraces.lookupat(C_NULL) == [StackTraces.UNKNOWN] == StackTraces.lookupat(C_NULL + 1) == StackTraces.lookupat(C_NULL - 1)
+@test StackTraces.lookup(C_NULL) == [StackTraces.UNKNOWN] == StackTraces.lookup(C_NULL + 1) == StackTraces.lookup(C_NULL - 1)
 
 let ct = current_task()
     # After a task switch, there should be nothing in catch_backtrace
@@ -118,7 +118,7 @@ let li = typeof(fieldtype).name.mt.cache.func::Core.MethodInstance,
 end
 
 let ctestptr = cglobal((:ctest, "libccalltest")),
-    ctest = StackTraces.lookupat(ctestptr)
+    ctest = StackTraces.lookup(ctestptr)
 
     @test length(ctest) == 1
     @test ctest[1].func === :ctest