Show correct line numbers for errors in an $(eval)

Bug: 264488559
Test: go test
Change-Id: I95ce0345912a2af351be0ecc4595bdc4a2047c0c

mk2rbc/mk2rbc.go

@@ -1872,6 +1872,18 @@ func (p *evalNodeParser) parse(ctx *parseContext, node mkparser.Node, args *mkpa
 	if len(nodes) == 0 {
 		return []starlarkNode{}
 	} else if len(nodes) == 1 {
+		// Replace the nodeLocator with one that just returns the location of
+		// the $(eval) node. Otherwise, statements inside an $(eval) will show as
+		// being on line 1 of the file, because they're on line 1 of
+		// strings.NewReader(args.Dump())
+		oldNodeLocator := ctx.script.nodeLocator
+		ctx.script.nodeLocator = func(pos mkparser.Pos) int {
+			return oldNodeLocator(node.Pos())
+		}
+		defer func() {
+			ctx.script.nodeLocator = oldNodeLocator
+		}()
+
 		switch n := nodes[0].(type) {
 		case *mkparser.Assignment:
 			if n.Name.Const() {

mk2rbc/mk2rbc_test.go

@@ -1567,6 +1567,9 @@ $(foreach x,$(MY_LIST_VAR), \
 
 $(foreach x,$(MY_LIST_VAR), \
   $(eval include foo/$(x).mk))
+
+# Check that we get as least close to correct line numbers for errors on statements inside evals
+$(eval $(call inherit-product,$(A_VAR)))
 `,
 		expected: `load("//build/make/core:product_config.rbc", "rblf")
 load("//foo:font.star", _font_init = "init")
@@ -1592,6 +1595,8 @@ def init(g, handle):
     if not _varmod_init:
       rblf.mkerror("product.mk", "Cannot find %s" % ("foo/%s.mk" % x))
     _varmod_init(g, handle)
+  # Check that we get as least close to correct line numbers for errors on statements inside evals
+  rblf.mk2rbc_error("product.mk:17", "inherit-product/include argument is too complex")
 `,
 	},
 	{