From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Tue, 21 Jan 2020 20:23:20 +0000 (-0800)
Subject: cmd/compile: dump contents when rulegen generates invalid code
X-Git-Tag: go1.15beta1~1170
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=0f7088ade502250a65402efde32c31f9c57f457b;p=gostls13.git

cmd/compile: dump contents when rulegen generates invalid code

It's much easier to debug when you can see
the contents in order to interpret the error message.

Change-Id: I03bbb9dd3071aeca9577cc725a60d43f78118cf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/215717
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
---

diff --git a/src/cmd/compile/internal/ssa/gen/rulegen.go b/src/cmd/compile/internal/ssa/gen/rulegen.go
index 47cf5f15da..5a22280218 100644
--- a/src/cmd/compile/internal/ssa/gen/rulegen.go
+++ b/src/cmd/compile/internal/ssa/gen/rulegen.go
@@ -22,6 +22,7 @@ import (
 	"go/printer"
 	"go/token"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 	"path"
@@ -264,7 +265,13 @@ func genRulesSuffix(arch arch, suff string) {
 	fset := token.NewFileSet()
 	file, err := parser.ParseFile(fset, "", buf, parser.ParseComments)
 	if err != nil {
-		log.Fatal(err)
+		filename := fmt.Sprintf("%s_broken.go", arch.name)
+		if err := ioutil.WriteFile(filename, buf.Bytes(), 0644); err != nil {
+			log.Printf("failed to dump broken code to %s: %v", filename, err)
+		} else {
+			log.Printf("dumped broken code to %s", filename)
+		}
+		log.Fatalf("failed to parse generated code for arch %s: %v", arch.name, err)
 	}
 	tfile := fset.File(file.Pos())