From 1843201324b4b3fba7d32185c29e0aadd22a44f0 Mon Sep 17 00:00:00 2001
From: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>
Date: Mon, 20 Sep 2021 13:57:12 +0900
Subject: [PATCH] optimizer: fix #42246, set `ssaflags` correctly when
 inserting coverage statements (#42260)

It seems that this change still doesn't resolve #42258 though.
---
 base/compiler/optimize.jl       | 13 +++++++++----
 base/compiler/ssair/ir.jl       |  6 +++---
 base/compiler/ssair/legacy.jl   |  2 +-
 base/compiler/ssair/slot2ssa.jl |  2 +-
 base/compiler/typeinfer.jl      |  2 +-
 test/compiler/inline.jl         | 22 ++++++++++++++++++++++
 6 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/base/compiler/optimize.jl b/base/compiler/optimize.jl
index fe0c058c533cb..5acfd22eb995a 100644
--- a/base/compiler/optimize.jl
+++ b/base/compiler/optimize.jl
@@ -142,6 +142,7 @@ const SLOT_USEDUNDEF    = 32 # slot has uses that might raise UndefVarError
 
 # NOTE make sure to sync the flag definitions below with julia.h and `jl_code_info_set_ir` in method.c
 
+const IR_FLAG_NULL        = 0x00
 # This statement is marked as @inbounds by user.
 # Ff replaced by inlining, any contained boundschecks may be removed.
 const IR_FLAG_INBOUNDS    = 0x01 << 0
@@ -349,15 +350,18 @@ function convert_to_ircode(ci::CodeInfo, code::Vector{Any}, coverage::Bool, sv::
     labelmap = coverage ? fill(0, length(code)) : changemap
     prevloc = zero(eltype(ci.codelocs))
     stmtinfo = sv.stmt_info
+    codelocs = ci.codelocs
     ssavaluetypes = ci.ssavaluetypes::Vector{Any}
+    ssaflags = ci.ssaflags
     while idx <= length(code)
-        codeloc = ci.codelocs[idx]
+        codeloc = codelocs[idx]
         if coverage && codeloc != prevloc && codeloc != 0
             # insert a side-effect instruction before the current instruction in the same basic block
             insert!(code, idx, Expr(:code_coverage_effect))
-            insert!(ci.codelocs, idx, codeloc)
+            insert!(codelocs, idx, codeloc)
             insert!(ssavaluetypes, idx, Nothing)
             insert!(stmtinfo, idx, nothing)
+            insert!(ssaflags, idx, IR_FLAG_NULL)
             changemap[oldidx] += 1
             if oldidx < length(labelmap)
                 labelmap[oldidx + 1] += 1
@@ -369,9 +373,10 @@ function convert_to_ircode(ci::CodeInfo, code::Vector{Any}, coverage::Bool, sv::
             if !(idx < length(code) && isa(code[idx + 1], ReturnNode) && !isdefined((code[idx + 1]::ReturnNode), :val))
                 # insert unreachable in the same basic block after the current instruction (splitting it)
                 insert!(code, idx + 1, ReturnNode())
-                insert!(ci.codelocs, idx + 1, ci.codelocs[idx])
+                insert!(codelocs, idx + 1, codelocs[idx])
                 insert!(ssavaluetypes, idx + 1, Union{})
                 insert!(stmtinfo, idx + 1, nothing)
+                insert!(ssaflags, idx + 1, ssaflags[idx])
                 if oldidx < length(changemap)
                     changemap[oldidx + 1] += 1
                     coverage && (labelmap[oldidx + 1] += 1)
@@ -391,7 +396,7 @@ function convert_to_ircode(ci::CodeInfo, code::Vector{Any}, coverage::Bool, sv::
     strip_trailing_junk!(ci, code, stmtinfo)
     cfg = compute_basic_blocks(code)
     types = Any[]
-    stmts = InstructionStream(code, types, stmtinfo, ci.codelocs, ci.ssaflags)
+    stmts = InstructionStream(code, types, stmtinfo, codelocs, ssaflags)
     ir = IRCode(stmts, cfg, collect(LineInfoNode, ci.linetable::Union{Vector{LineInfoNode},Vector{Any}}), sv.slottypes, meta, sv.sptypes)
     return ir
 end
diff --git a/base/compiler/ssair/ir.jl b/base/compiler/ssair/ir.jl
index a2eaf5c69cbdd..d3d62c9b2dfaa 100644
--- a/base/compiler/ssair/ir.jl
+++ b/base/compiler/ssair/ir.jl
@@ -172,7 +172,7 @@ end
 NewInstruction(@nospecialize(stmt), @nospecialize(type)) =
     NewInstruction(stmt, type, nothing)
 NewInstruction(@nospecialize(stmt), @nospecialize(type), line::Union{Nothing, Int32}) =
-    NewInstruction(stmt, type, nothing, line, 0x00, false)
+    NewInstruction(stmt, type, nothing, line, IR_FLAG_NULL, false)
 
 effect_free(inst::NewInstruction) =
     NewInstruction(inst.stmt, inst.type, inst.info, inst.line, inst.flag | IR_FLAG_EFFECT_FREE, true)
@@ -193,7 +193,7 @@ function InstructionStream(len::Int)
     info = Array{Any}(undef, len)
     fill!(info, nothing)
     lines = fill(Int32(0), len)
-    flags = fill(0x00, len)
+    flags = fill(IR_FLAG_NULL, len)
     return InstructionStream(insts, types, info, lines, flags)
 end
 InstructionStream() = InstructionStream(0)
@@ -221,7 +221,7 @@ function resize!(stmts::InstructionStream, len)
     resize!(stmts.flag, len)
     for i in (old_length + 1):len
         stmts.line[i] = 0
-        stmts.flag[i] = 0x00
+        stmts.flag[i] = IR_FLAG_NULL
         stmts.info[i] = nothing
     end
     return stmts
diff --git a/base/compiler/ssair/legacy.jl b/base/compiler/ssair/legacy.jl
index a832daa8ed418..4d2bafc2f38d9 100644
--- a/base/compiler/ssair/legacy.jl
+++ b/base/compiler/ssair/legacy.jl
@@ -48,7 +48,7 @@ function replace_code_newstyle!(ci::CodeInfo, ir::IRCode, nargs::Int)
         push!(ci.code, metanode)
         push!(ci.codelocs, 1)
         push!(ci.ssavaluetypes::Vector{Any}, Any)
-        push!(ci.ssaflags, 0x00)
+        push!(ci.ssaflags, IR_FLAG_NULL)
     end
     # Translate BB Edges to statement edges
     # (and undo normalization for now)
diff --git a/base/compiler/ssair/slot2ssa.jl b/base/compiler/ssair/slot2ssa.jl
index 489c98c6549cc..656df9b17e4c4 100644
--- a/base/compiler/ssair/slot2ssa.jl
+++ b/base/compiler/ssair/slot2ssa.jl
@@ -195,7 +195,7 @@ function strip_trailing_junk!(ci::CodeInfo, code::Vector{Any}, info::Vector{Any}
         push!(ssavaluetypes, Union{})
         push!(ci.codelocs, 0)
         push!(info, nothing)
-        push!(ci.ssaflags, 0x00)
+        push!(ci.ssaflags, IR_FLAG_NULL)
     end
     nothing
 end
diff --git a/base/compiler/typeinfer.jl b/base/compiler/typeinfer.jl
index f301b8a1756d9..c3b7c4dc3a3d0 100644
--- a/base/compiler/typeinfer.jl
+++ b/base/compiler/typeinfer.jl
@@ -866,7 +866,7 @@ function typeinf_ext(interp::AbstractInterpreter, mi::MethodInstance)
                 tree.code = Any[ ReturnNode(quoted(rettype_const)) ]
                 nargs = Int(method.nargs)
                 tree.slotnames = ccall(:jl_uncompress_argnames, Vector{Symbol}, (Any,), method.slot_syms)
-                tree.slotflags = fill(0x00, nargs)
+                tree.slotflags = fill(IR_FLAG_NULL, nargs)
                 tree.ssavaluetypes = 1
                 tree.codelocs = Int32[1]
                 tree.linetable = [LineInfoNode(method.module, method.name, method.file, Int(method.line), 0)]
diff --git a/test/compiler/inline.jl b/test/compiler/inline.jl
index a276e6ef65c77..e26d834817d7f 100644
--- a/test/compiler/inline.jl
+++ b/test/compiler/inline.jl
@@ -650,3 +650,25 @@ let
         @test ninlined == length(code)
     end
 end
+
+# https://github.com/JuliaLang/julia/issues/42246
+@test mktempdir() do dir
+    cd(dir) do
+        code = quote
+            issue42246() = @noinline IOBuffer("a")
+            let
+                ci, rt = only(code_typed(issue42246))
+                if any(ci.code) do stmt
+                       Meta.isexpr(stmt, :invoke) &&
+                       stmt.args[1].def.name === nameof(IOBuffer)
+                   end
+                    exit(0)
+                else
+                    exit(1)
+               end
+            end
+        end |> string
+        cmd = `$(Base.julia_cmd()) --code-coverage=tmp.info -e $code`
+        success(pipeline(Cmd(cmd); stdout=stdout, stderr=stderr))
+    end
+end