gopls: return file error if file open fails
The bug manifests itself when a non-existent file is passed in as an
argument to gopls, causing a nil pointer dereference panic. This is due
to an attempt to reference the "mapper" attribute, which is not set if
the file is not found.
The resolution is to check for an informative error that is set on the
file instance after "getFile" is called and return it immediately to the
caller to allow the error to propagate up to the main() function and
print the error to stdout.
Testing:
--------
Non-existent file:
$ gopls -rpc.trace -v check gopls/doesnotexist.go
check: file:///Users/albertteoh/repo/tools/gopls/doesnotexist.go: open /Users/albertteoh/repo/tools/gopls/doesnotexist.go: no such file or directory
Existing go file:
$ gopls -rpc.trace -v check internal/lsp/definition.go
2019/08/03 13:33:00 Info:go/packages.Load
packages = 2
2019/08/03 13:33:00 Info:go/packages.Load
package = golang.org/x/tools/internal/lsp
...
Fixes golang/go#33445
Change-Id: Ib56d8a4b7f23f4882b75cf684c5d18a49d27b824
Reviewed-on: https://go-review.googlesource.com/c/tools/+/188857
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/internal/lsp/cmd/cmd.go b/internal/lsp/cmd/cmd.go
index 66ac3d9..88ccafd 100644
--- a/internal/lsp/cmd/cmd.go
+++ b/internal/lsp/cmd/cmd.go
@@ -350,15 +350,16 @@
defer c.Client.filesMu.Unlock()
file := c.Client.getFile(ctx, uri)
- if !file.added {
- file.added = true
- p := &protocol.DidOpenTextDocumentParams{}
- p.TextDocument.URI = string(uri)
- p.TextDocument.Text = string(file.mapper.Content)
- p.TextDocument.LanguageID = source.DetectLanguage("", file.uri.Filename()).String()
- if err := c.Server.DidOpen(ctx, p); err != nil {
- file.err = fmt.Errorf("%v: %v", uri, err)
- }
+ if file.err != nil || file.added {
+ return file
+ }
+ file.added = true
+ p := &protocol.DidOpenTextDocumentParams{}
+ p.TextDocument.URI = string(uri)
+ p.TextDocument.Text = string(file.mapper.Content)
+ p.TextDocument.LanguageID = source.DetectLanguage("", file.uri.Filename()).String()
+ if err := c.Server.DidOpen(ctx, p); err != nil {
+ file.err = fmt.Errorf("%v: %v", uri, err)
}
return file
}
