coverage: ensure topline is recorded during inlining (JuliaLang#42170)

Fixes JuliaCI/CoverageTools.jl#48

base/compiler/ssair/inlining.jl

@@ -304,29 +304,47 @@ function ir_inline_item!(compact::IncrementalCompact, idx::Int, argexprs::Vector
                          boundscheck::Symbol, todo_bbs::Vector{Tuple{Int, Int}})
     # Ok, do the inlining here
     spec = item.spec::ResolvedInliningSpec
+    sparam_vals = item.mi.sparam_vals
+    def = item.mi.def::Method
     inline_cfg = spec.ir.cfg
     stmt = compact.result[idx][:inst]
     linetable_offset::Int32 = length(linetable)
     # Append the linetable of the inlined function to our line table
     inlined_at = Int(compact.result[idx][:line])
-    for entry in spec.ir.linetable
-        push!(linetable, LineInfoNode(entry.module, entry.method, entry.file, entry.line,
-            (entry.inlined_at > 0 ? entry.inlined_at + linetable_offset : inlined_at)))
+    topline::Int32 = linetable_offset + Int32(1)
+    coverage = coverage_enabled(def.module)
+    push!(linetable, LineInfoNode(def.module, def.name, def.file, Int(def.line), inlined_at))
+    oldlinetable = spec.ir.linetable
+    for oldline in 1:length(oldlinetable)
+        entry = oldlinetable[oldline]
+        newentry = LineInfoNode(entry.module, entry.method, entry.file, entry.line,
+            (entry.inlined_at > 0 ? entry.inlined_at + linetable_offset + (oldline == 1) : inlined_at))
+        if oldline == 1
+            # check for a duplicate on the first iteration (likely true)
+            if newentry === linetable[topline]
+                continue
+            else
+                linetable_offset += 1
+            end
+        end
+        push!(linetable, newentry)
+    end
+    if coverage && spec.ir.stmts[1][:line] + linetable_offset != topline
+        insert_node_here!(compact, NewInstruction(Expr(:code_coverage_effect), Nothing, topline))
     end
-    (; def, sparam_vals) = item.mi
     nargs_def = def.nargs::Int32
     isva = nargs_def > 0 && def.isva
     sig = def.sig
     if isva
-        vararg = mk_tuplecall!(compact, argexprs[nargs_def:end], compact.result[idx][:line])
+        vararg = mk_tuplecall!(compact, argexprs[nargs_def:end], topline)
         argexprs = Any[argexprs[1:(nargs_def - 1)]..., vararg]
     end
-    is_opaque = isa(def, Method) && def.is_for_opaque_closure
+    is_opaque = def.is_for_opaque_closure
     if is_opaque
         # Replace the first argument by a load of the capture environment
         argexprs[1] = insert_node_here!(compact,
             NewInstruction(Expr(:call, GlobalRef(Core, :getfield), argexprs[1], QuoteNode(:captures)),
-            spec.ir.argtypes[1], compact.result[idx][:line]))
+            spec.ir.argtypes[1], topline))
     end
     flag = compact.result[idx][:flag]
     boundscheck_idx = boundscheck

test/testhelpers/coverage_file.info

@@ -10,9 +10,9 @@ DA:11,1
 DA:12,1
 DA:14,0
 DA:17,1
-DA:19,1
+DA:19,2
 DA:20,1
 DA:22,1
-LH:10
-LF:13
+LH:12
+LF:14
 end_of_record

test/testhelpers/coverage_file.info.bad

@@ -11,7 +11,7 @@ DA:12,1
 DA:14,0
 DA:17,1
 DA:18,0
-DA:19,1
+DA:19,2
 DA:20,1
 DA:22,1
 DA:1234,0