[IR] Add a boolean field in DILocation to know if a line must covered or not

Summary:
Some lines have a hit counter where they should not have one.
For example, in C++, some cleanup is adding at the end of a scope represented by a '}'.
So such a line has a hit counter where a user expects to not have one.
The goal of the patch is to add this information in DILocation which is used to get the covered lines in GCOVProfiling.cpp.
A following patch in clang will add this information when generating IR (https://reviews.llvm.org/D49916).

Reviewers: marco-c, davidxl, vsk, javed.absar, rnk

Reviewed By: rnk

Subscribers: eraman, xur, danielcdh, aprantl, rnk, dblaikie, #debug-info, vsk, llvm-commits, sylvestre.ledru

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D49915

llvm-svn: 342631
diff --git a/llvm/test/Bitcode/DILocation-implicit-code.ll b/llvm/test/Bitcode/DILocation-implicit-code.ll
new file mode 100644
index 0000000..03daa0f
--- /dev/null
+++ b/llvm/test/Bitcode/DILocation-implicit-code.ll
@@ -0,0 +1,190 @@
+; RUN: llvm-dis %s.bc -o - | FileCheck %s
+; ModuleID = 'DILocation-implicit-code.cpp'
+source_filename = "DILocation-implicit-code.cpp"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.A = type { i8 }
+
+$_ZN1AC2Ev = comdat any
+
+$_ZN1A3fooEi = comdat any
+
+@_ZTIi = external dso_local constant i8*
+
+; Function Attrs: noinline optnone uwtable
+define dso_local void @_Z5test1v() #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) !dbg !7 {
+entry:
+  %retval = alloca %struct.A, align 1
+  %a = alloca %struct.A, align 1
+  %exn.slot = alloca i8*
+  %ehselector.slot = alloca i32
+  %undef.agg.tmp = alloca %struct.A, align 1
+  %e = alloca i32, align 4
+  %undef.agg.tmp3 = alloca %struct.A, align 1
+  call void @_ZN1AC2Ev(%struct.A* %a), !dbg !9
+  invoke void @_ZN1A3fooEi(%struct.A* %a, i32 0)
+          to label %invoke.cont unwind label %lpad, !dbg !10
+
+invoke.cont:                                      ; preds = %entry
+  br label %return, !dbg !11
+
+lpad:                                             ; preds = %entry
+  %0 = landingpad { i8*, i32 }
+          catch i8* bitcast (i8** @_ZTIi to i8*), !dbg !12
+  %1 = extractvalue { i8*, i32 } %0, 0, !dbg !12
+  store i8* %1, i8** %exn.slot, align 8, !dbg !12
+  %2 = extractvalue { i8*, i32 } %0, 1, !dbg !12
+  store i32 %2, i32* %ehselector.slot, align 4, !dbg !12
+  br label %catch.dispatch, !dbg !12
+
+catch.dispatch:                                   ; preds = %lpad
+  %sel = load i32, i32* %ehselector.slot, align 4, !dbg !13
+  %3 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #4, !dbg !13
+  %matches = icmp eq i32 %sel, %3, !dbg !13
+  br i1 %matches, label %catch, label %eh.resume, !dbg !13
+
+catch:                                            ; preds = %catch.dispatch
+  %exn = load i8*, i8** %exn.slot, align 8, !dbg !13
+  %4 = call i8* @__cxa_begin_catch(i8* %exn) #4, !dbg !13
+  %5 = bitcast i8* %4 to i32*, !dbg !13
+  %6 = load i32, i32* %5, align 4, !dbg !13
+  store i32 %6, i32* %e, align 4, !dbg !13
+  %7 = load i32, i32* %e, align 4, !dbg !14
+  invoke void @_ZN1A3fooEi(%struct.A* %a, i32 %7)
+          to label %invoke.cont2 unwind label %lpad1, !dbg !15
+
+invoke.cont2:                                     ; preds = %catch
+  call void @__cxa_end_catch() #4, !dbg !16
+  br label %return
+
+lpad1:                                            ; preds = %catch
+  %8 = landingpad { i8*, i32 }
+          cleanup, !dbg !12
+  %9 = extractvalue { i8*, i32 } %8, 0, !dbg !12
+  store i8* %9, i8** %exn.slot, align 8, !dbg !12
+  %10 = extractvalue { i8*, i32 } %8, 1, !dbg !12
+  store i32 %10, i32* %ehselector.slot, align 4, !dbg !12
+  call void @__cxa_end_catch() #4, !dbg !16
+  br label %eh.resume, !dbg !16
+
+try.cont:                                         ; No predecessors!
+  call void @llvm.trap(), !dbg !16
+  unreachable, !dbg !16
+
+return:                                           ; preds = %invoke.cont2, %invoke.cont
+  ret void, !dbg !12
+
+eh.resume:                                        ; preds = %lpad1, %catch.dispatch
+  %exn4 = load i8*, i8** %exn.slot, align 8, !dbg !13
+  %sel5 = load i32, i32* %ehselector.slot, align 4, !dbg !13
+  %lpad.val = insertvalue { i8*, i32 } undef, i8* %exn4, 0, !dbg !13
+  %lpad.val6 = insertvalue { i8*, i32 } %lpad.val, i32 %sel5, 1, !dbg !13
+  resume { i8*, i32 } %lpad.val6, !dbg !13
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define linkonce_odr dso_local void @_ZN1AC2Ev(%struct.A* %this) unnamed_addr #1 comdat align 2 !dbg !17 {
+entry:
+  %this.addr = alloca %struct.A*, align 8
+  store %struct.A* %this, %struct.A** %this.addr, align 8
+  %this1 = load %struct.A*, %struct.A** %this.addr, align 8
+  ret void, !dbg !18
+}
+
+; Function Attrs: noinline optnone uwtable
+define linkonce_odr dso_local void @_ZN1A3fooEi(%struct.A* %this, i32 %i) #0 comdat align 2 !dbg !19 {
+entry:
+  %retval = alloca %struct.A, align 1
+  %this.addr = alloca %struct.A*, align 8
+  %i.addr = alloca i32, align 4
+  store %struct.A* %this, %struct.A** %this.addr, align 8
+  store i32 %i, i32* %i.addr, align 4
+  %this1 = load %struct.A*, %struct.A** %this.addr, align 8
+  %0 = load i32, i32* %i.addr, align 4, !dbg !20
+  %cmp = icmp eq i32 %0, 0, !dbg !21
+  br i1 %cmp, label %if.then, label %if.end, !dbg !20
+
+if.then:                                          ; preds = %entry
+  %exception = call i8* @__cxa_allocate_exception(i64 4) #4, !dbg !22
+  %1 = bitcast i8* %exception to i32*, !dbg !22
+  store i32 1, i32* %1, align 16, !dbg !22
+  call void @__cxa_throw(i8* %exception, i8* bitcast (i8** @_ZTIi to i8*), i8* null) #5, !dbg !22
+  unreachable, !dbg !22
+
+if.end:                                           ; preds = %entry
+  ret void, !dbg !23
+}
+
+declare dso_local i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.eh.typeid.for(i8*) #2
+
+declare dso_local i8* @__cxa_begin_catch(i8*)
+
+declare dso_local void @__cxa_end_catch()
+
+; Function Attrs: noreturn nounwind
+declare void @llvm.trap() #3
+
+; Function Attrs: noinline optnone uwtable
+define dso_local void @_Z5test2v() #0 !dbg !24 {
+entry:
+  %a = alloca %struct.A, align 1
+  %b = alloca %struct.A, align 1
+  %undef.agg.tmp = alloca %struct.A, align 1
+  call void @_ZN1AC2Ev(%struct.A* %a), !dbg !25
+  call void @_ZN1A3fooEi(%struct.A* %a, i32 1), !dbg !26
+  ret void, !dbg !27
+}
+
+declare dso_local i8* @__cxa_allocate_exception(i64)
+
+declare dso_local void @__cxa_throw(i8*, i8*, i8*)
+
+attributes #0 = { noinline optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind readnone }
+attributes #3 = { noreturn nounwind }
+attributes #4 = { nounwind }
+attributes #5 = { noreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+; CHECK: !DILocation(line: 20, column: 1, scope: !{{[0-9]+}}, isImplicitCode: true)
+; CHECK: !DILocation(line: 17, column: 5, scope: !{{[0-9]+}}, isImplicitCode: true)
+; CHECK: !DILocation(line: 19, column: 5, scope: !{{[0-9]+}}, isImplicitCode: true)
+; CHECK: !DILocation(line: 3, column: 10, scope: !{{[0-9]+}}, isImplicitCode: true)
+; CHECK: !DILocation(line: 25, column: 1, scope: !{{[0-9]+}}, isImplicitCode: true)
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0 (trunk 342445)", isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "DILocation-implicit-code.cpp", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 342445)"}
+!7 = distinct !DISubprogram(name: "test1", scope: !1, file: !1, line: 13, type: !8, isLocal: false, isDefinition: true, scopeLine: 13, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !2)
+!9 = !DILocation(line: 14, column: 7, scope: !7)
+!10 = !DILocation(line: 16, column: 18, scope: !7)
+!11 = !DILocation(line: 16, column: 9, scope: !7)
+!12 = !DILocation(line: 20, column: 1, scope: !7, isImplicitCode: true)
+!13 = !DILocation(line: 17, column: 5, scope: !7, isImplicitCode: true)
+!14 = !DILocation(line: 18, column: 22, scope: !7)
+!15 = !DILocation(line: 18, column: 18, scope: !7)
+!16 = !DILocation(line: 19, column: 5, scope: !7, isImplicitCode: true)
+!17 = distinct !DISubprogram(name: "A", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!18 = !DILocation(line: 3, column: 10, scope: !17, isImplicitCode: true)
+!19 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 4, type: !8, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!20 = !DILocation(line: 5, column: 13, scope: !19)
+!21 = !DILocation(line: 5, column: 15, scope: !19)
+!22 = !DILocation(line: 6, column: 13, scope: !19)
+!23 = !DILocation(line: 9, column: 9, scope: !19)
+!24 = distinct !DISubprogram(name: "test2", scope: !1, file: !1, line: 22, type: !8, isLocal: false, isDefinition: true, scopeLine: 22, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!25 = !DILocation(line: 23, column: 7, scope: !24)
+!26 = !DILocation(line: 24, column: 13, scope: !24)
+!27 = !DILocation(line: 25, column: 1, scope: !24, isImplicitCode: true)