cmd/compile: remove statement marks from secondary calls

Calls are code-generated in an alternate path that inherits
its positions from values, not from *SSAGenState.  The
default position on *SSAGenState was marked as not-a-statement,
but this was not applied to the value itself, leading to
spurious "is statement" marks in the output (convention:
after code generation in the compiler, everything is either
definitely a statement or definitely not a statement, nothing
is in the undetermined state).

This CL causes a 35 statement regression in ssa/stmtlines_test.
This is down from the earlier 150 because of all the other
CLs preceding this one that deal with the root causes of the
missing lines (repeated lines on nested calls hid missing lines).

This also removes some line repeats from ssa/debug_test.

Change-Id: Ie9a507bd5447e906b35bbd098e3295211df2ae01
Reviewed-on: https://go-review.googlesource.com/c/go/+/188018
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>

4 files changed, 19 insertions, 45 deletions

diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index ed1cccc6b0..a263fa7e99 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -5238,8 +5238,11 @@ func (s *SSAGenState) DebugFriendlySetPosFrom(v *ssa.Value) {
 			// in the generated code.
 			if p.IsStmt() != src.PosIsStmt {
 				p = p.WithNotStmt()
+				// Calls use the pos attached to v, but copy the statement mark from SSAGenState
 			}
 			s.SetPos(p)
+		} else {
+			s.SetPos(s.pp.pos.WithNotStmt())
 		}
 	}
 }
@@ -5878,10 +5881,15 @@ func (s *SSAGenState) AddrScratch(a *obj.Addr) {
 // Call returns a new CALL instruction for the SSA value v.
 // It uses PrepareCall to prepare the call.
 func (s *SSAGenState) Call(v *ssa.Value) *obj.Prog {
+	pPosIsStmt := s.pp.pos.IsStmt() // The statement-ness fo the call comes from ssaGenState
 	s.PrepareCall(v)
 
 	p := s.Prog(obj.ACALL)
-	p.Pos = v.Pos
+	if pPosIsStmt == src.PosIsStmt {
+		p.Pos = v.Pos.WithIsStmt()
+	} else {
+		p.Pos = v.Pos.WithNotStmt()
+	}
 	if sym, ok := v.Aux.(*obj.LSym); ok {
 		p.To.Type = obj.TYPE_MEM
 		p.To.Name = obj.NAME_EXTERN
diff --git a/src/cmd/compile/internal/ssa/testdata/hist.dlv-opt.nexts b/src/cmd/compile/internal/ssa/testdata/hist.dlv-opt.nexts
index 1e4d35051b..2be83ce936 100644
--- a/src/cmd/compile/internal/ssa/testdata/hist.dlv-opt.nexts
+++ b/src/cmd/compile/internal/ssa/testdata/hist.dlv-opt.nexts
@@ -70,32 +70,24 @@
 87:			if a == 0 { //gdb-opt=(a,n,t)
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 86:		for i, a := range hist {
diff --git a/src/cmd/compile/internal/ssa/testdata/hist.gdb-dbg.nexts b/src/cmd/compile/internal/ssa/testdata/hist.gdb-dbg.nexts
index 4fde3bcc66..72df60c76f 100644
--- a/src/cmd/compile/internal/ssa/testdata/hist.gdb-dbg.nexts
+++ b/src/cmd/compile/internal/ssa/testdata/hist.gdb-dbg.nexts
@@ -9,7 +9,7 @@ l.end.y = 4
 61:		sink = dx + dy            //gdb-opt=(dx,dy)
 63:		hist := make([]int, 7)                                //gdb-opt=(dx/O,dy/O) // TODO sink is missing if this code is in 'test' instead of 'main'
 64:		var reader io.Reader = strings.NewReader(cannedInput) //gdb-dbg=(hist/A) // TODO cannedInput/A is missing if this code is in 'test' instead of 'main'
-hist =  []int = {0, 0, 0, 0, 0, 0, 0}
+hist = {array = <A>, len = 7, cap = 7}
 65:		if len(os.Args) > 1 {
 73:		scanner := bufio.NewScanner(reader)
 74:		for scanner.Scan() { //gdb-opt=(scanner/A)
diff --git a/src/cmd/compile/internal/ssa/testdata/hist.gdb-opt.nexts b/src/cmd/compile/internal/ssa/testdata/hist.gdb-opt.nexts
index 65c5d0a2ce..d3a34acf69 100644
--- a/src/cmd/compile/internal/ssa/testdata/hist.gdb-opt.nexts
+++ b/src/cmd/compile/internal/ssa/testdata/hist.gdb-opt.nexts
@@ -24,92 +24,74 @@ scanner = (bufio.Scanner *) <A>
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 0, 0, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 1
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 1, 0, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 1
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 2, 0, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 1
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 0, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 2
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 1, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 2
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 2, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 2
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 3, 0, 0, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 4
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 3, 0, 1, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 4
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 75:			s := scanner.Text()
 76:			i, err := strconv.ParseInt(s, 10, 64)
 77:			if err != nil { //gdb-dbg=(i) //gdb-opt=(err,hist,i)
 err = {tab = 0x0, data = 0x0}
-hist =  []int = {0, 3, 3, 0, 2, 0, 0}
+hist = {array = 0xc00005ae50, len = 7, cap = 7}
 i = 5
 81:			hist = ensure(int(i), hist)
 82:			hist[int(i)]++
-74:		for scanner.Scan() { //gdb-opt=(scanner/A)
-scanner = (bufio.Scanner *) <A>
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 a = 0
@@ -122,9 +104,7 @@ n = 0
 t = 0
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 a = 3
@@ -132,9 +112,7 @@ n = 3
 t = 3
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 a = 0
@@ -147,9 +125,7 @@ n = 6
 t = 9
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 a = 1
@@ -157,9 +133,7 @@ n = 8
 t = 17
 92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 91:			n += a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 90:			t += i * a
-92:			fmt.Fprintf(os.Stderr, "%d\t%d\t%d\t%d\t%d\n", i, a, n, i*a, t) //gdb-dbg=(n,i,t)
 86:		for i, a := range hist {
 87:			if a == 0 { //gdb-opt=(a,n,t)
 a = 0