Fix error reporting when parsing genrule cmd

Report errors inside the android.Expand lambda and don't return an
error so that processing can continue and multiple errors can be
reported.  Check for errors (for example incorrect syntax of variables)
immediately after Expand returns.  Avoids a misleading error message:
specified depfile=true but did not include a reference to '${depfile}' in cmd

Bug: 111219250
Test: m checkbuild
Change-Id: Id9a16c1609f5fd9345bfa1a2191261cff72fd382

1 files changed, 16 insertions, 11 deletions

diff --git a/genrule/genrule.go b/genrule/genrule.go
index d03d4ee2..03d4ea6f 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -223,13 +223,18 @@ func (g *Module) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	task := g.taskGenerator(ctx, String(g.properties.Cmd), srcFiles)
 
 	rawCommand, err := android.Expand(task.cmd, func(name string) (string, error) {
+		// report the error directly without returning an error to android.Expand to catch multiple errors in a
+		// single run
+		reportError := func(fmt string, args ...interface{}) (string, error) {
+			ctx.PropertyErrorf("cmd", fmt, args...)
+			return "SOONG_ERROR", nil
+		}
+
 		switch name {
 		case "location":
 			if len(g.properties.Tools) == 0 && len(toolFiles) == 0 {
-				return "", fmt.Errorf("at least one `tools` or `tool_files` is required if $(location) is used")
-			}
-
-			if len(g.properties.Tools) > 0 {
+				return reportError("at least one `tools` or `tool_files` is required if $(location) is used")
+			} else if len(g.properties.Tools) > 0 {
 				return tools[g.properties.Tools[0]].String(), nil
 			} else {
 				return tools[toolFiles[0].Rel()].String(), nil
@@ -241,7 +246,7 @@ func (g *Module) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		case "depfile":
 			referencedDepfile = true
 			if !Bool(g.properties.Depfile) {
-				return "", fmt.Errorf("$(depfile) used without depfile property")
+				return reportError("$(depfile) used without depfile property")
 			}
 			return "__SBOX_DEPFILE__", nil
 		case "genDir":
@@ -252,22 +257,22 @@ func (g *Module) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 				if tool, ok := tools[label]; ok {
 					return tool.String(), nil
 				} else {
-					return "", fmt.Errorf("unknown location label %q", label)
+					return reportError("unknown location label %q", label)
 				}
 			}
-			return "", fmt.Errorf("unknown variable '$(%s)'", name)
+			return reportError("unknown variable '$(%s)'", name)
 		}
 	})
 
-	if Bool(g.properties.Depfile) && !referencedDepfile {
-		ctx.PropertyErrorf("cmd", "specified depfile=true but did not include a reference to '${depfile}' in cmd")
-	}
-
 	if err != nil {
 		ctx.PropertyErrorf("cmd", "%s", err.Error())
 		return
 	}
 
+	if Bool(g.properties.Depfile) && !referencedDepfile {
+		ctx.PropertyErrorf("cmd", "specified depfile=true but did not include a reference to '${depfile}' in cmd")
+	}
+
 	// tell the sbox command which directory to use as its sandbox root
 	buildDir := android.PathForOutput(ctx).String()
 	sandboxPath := shared.TempDirForOutDir(buildDir)