Fix missing dependency file with -Zunpretty

compiler/rustc_driver_impl/src/lib.rs

@@ -393,6 +393,10 @@ fn run_compiler(
                         pretty::print_after_hir_lowering(tcx, *ppm);
                         Ok(())
                     })?;
+
+                    // Make sure the `output_filenames` query is run for its side
+                    // effects of writing the dep-info and reporting errors.
+                    queries.global_ctxt()?.enter(|tcx| tcx.output_filenames(()));
                 } else {
                     let krate = queries.parse()?.steal();
                     pretty::print_after_parsing(sess, &krate, *ppm);

tests/run-make/pretty-print-with-dep-file/Makefile

@@ -0,0 +1,9 @@
+include ../tools.mk
+
+all:
+	$(RUSTC) --emit=dep-info -Zunpretty=expanded with-dep.rs
+	$(CGREP) "with-dep.rs" < $(TMPDIR)/with-dep.d
+	-rm $(TMPDIR)/with-dep.d
+
+	$(RUSTC) --emit=dep-info -Zunpretty=normal with-dep.rs
+	! test -f $(TMPDIR)/with-dep.d

tests/run-make/pretty-print-with-dep-file/with-dep.rs

@@ -0,0 +1 @@
+fn main() {}