[Compiler] begin new approach to verify --trim output (#57530)

Reimplement all of the trim verification support in Julia as a compiler
analysis pass. Move all this verification code into the Compiler julia
code, where we have much better utilities for pretty printing and better
observability for analysis.

(cherry picked from commit 1045bd8)

Author: vtjnash

Compiler/src/Compiler.jl

@@ -188,14 +188,19 @@ macro __SOURCE_FILE__()
     return QuoteNode(__source__.file::Symbol)
 end
 
-module IRShow end
+module IRShow end # relies on string and IO operations defined in Base
+baremodule TrimVerifier end # relies on IRShow, so define this afterwards
+
 function load_irshow!()
     if isdefined(Base, :end_base_include)
         # This code path is exclusively for Revise, which may want to re-run this
         # after bootstrap.
-        include(IRShow, Base.joinpath(Base.dirname(Base.String(@__SOURCE_FILE__)), "ssair/show.jl"))
+        Compilerdir = Base.dirname(Base.String(@__SOURCE_FILE__))
+        include(IRShow, Base.joinpath(Compilerdir, "ssair/show.jl"))
+        include(TrimVerifier, Base.joinpath(Compilerdir, "verifytrim.jl"))
     else
         include(IRShow, "ssair/show.jl")
+        include(TrimVerifier, "verifytrim.jl")
     end
 end
 if !isdefined(Base, :end_base_include)

Compiler/src/bootstrap.jl

@@ -71,7 +71,7 @@ function bootstrap!()
                 end
             end
         end
-        codeinfos = typeinf_ext_toplevel(methods, [world], false)
+        codeinfos = typeinf_ext_toplevel(methods, [world], TRIM_NO)
         for i = 1:2:length(codeinfos)
             ci = codeinfos[i]::CodeInstance
             src = codeinfos[i + 1]::CodeInfo

Compiler/src/typeinfer.jl

@@ -1273,7 +1273,12 @@ function typeinf_ext_toplevel(mi::MethodInstance, world::UInt, source_mode::UInt
 end
 
 # This is a bridge for the C code calling `jl_typeinf_func()` on set of Method matches
-function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim::Bool)
+# The trim_mode can be any of:
+const TRIM_NO = 0
+const TRIM_SAFE = 1
+const TRIM_UNSAFE = 2
+const TRIM_UNSAFE_WARN = 3
+function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim_mode::Int)
     inspected = IdSet{CodeInstance}()
     tocompile = Vector{CodeInstance}()
     codeinfos = []
@@ -1321,7 +1326,7 @@ function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim::
                 src = codeinfo_for_const(interp, mi, callee.rettype_const)
             elseif haskey(interp.codegen, callee)
                 src = interp.codegen[callee]
-            elseif isa(def, Method) && ccall(:jl_get_module_infer, Cint, (Any,), def.module) == 0 && !trim
+            elseif isa(def, Method) && ccall(:jl_get_module_infer, Cint, (Any,), def.module) == 0 && trim_mode == TRIM_NO
                 src = retrieve_code_info(mi, get_inference_world(interp))
             else
                 # TODO: typeinf_code could return something with different edges/ages/owner/abi (needing an update to callee), which we don't handle here
@@ -1336,15 +1341,19 @@ function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim::
                 end
                 push!(codeinfos, callee)
                 push!(codeinfos, src)
-            elseif trim
-                println("warning: failed to get code for ", mi)
             end
         end
         latest = false
     end
+    if trim_mode != TRIM_NO && trim_mode != TRIM_UNSAFE
+        verify_typeinf_trim(codeinfos, trim_mode == TRIM_UNSAFE_WARN)
+    end
     return codeinfos
 end
 
+verify_typeinf_trim(io::IO, codeinfos::Vector{Any}, onlywarn::Bool) = (msg = "--trim verifier not defined"; onlywarn ? println(io, msg) : error(msg))
+verify_typeinf_trim(codeinfos::Vector{Any}, onlywarn::Bool) = invokelatest(verify_typeinf_trim, stdout, codeinfos, onlywarn)
+
 function return_type(@nospecialize(f), t::DataType) # this method has a special tfunc
     world = tls_world_age()
     args = Any[_return_type, NativeInterpreter(world), Tuple{Core.Typeof(f), t.parameters...}]