Check generated save-analysis, instead of bug!()ing

Injected crates don't have extern info. Let's skip them.

Author: sinkuu

src/librustc_save_analysis/lib.rs

@@ -115,7 +115,8 @@ impl<'l, 'tcx: 'l> SaveContext<'l, 'tcx> {
             let span = match *self.tcx.extern_crate(n.as_def_id()) {
                 Some(ExternCrate { span, .. }) => span,
                 None => {
-                    bug!("no data for crate {}", n);
+                    debug!("Skipping crate {}, no data", n);
+                    continue;
                 }
             };
             let lo_loc = self.span_utils.sess.codemap().lookup_char_pos(span.lo());

src/test/run-make-fulldeps/save-analysis-rfc2126/Makefile

@@ -2,7 +2,9 @@
 
 all: extern_absolute_paths.rs extern_in_paths.rs krate2
 	$(RUSTC) extern_absolute_paths.rs -Zsave-analysis
+	cat $(TMPDIR)/save-analysis/extern_absolute_paths.json | "$(PYTHON)" validate_json.py
 	$(RUSTC) extern_in_paths.rs -Zsave-analysis
+	cat $(TMPDIR)/save-analysis/extern_in_paths.json | "$(PYTHON)" validate_json.py
 
 krate2: krate2.rs
 	$(RUSTC) $<

src/test/run-make-fulldeps/save-analysis-rfc2126/validate_json.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+
+# Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution and at
+# http://rust-lang.org/COPYRIGHT.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+import sys
+import json
+
+crates = json.loads(sys.stdin.readline().strip())["prelude"]["external_crates"]
+assert any(map(lambda c: c["id"]["name"] == "krate2", crates))