From d488500812424061264a69c9ecfe0247bc00d1af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= <tomasz.miasko@gmail.com>
Date: Sun, 13 Oct 2019 00:00:00 +0000
Subject: [PATCH] Don't discard value names when using address or memory
 sanitizer

The value names are used when reporting issues found by address
sanitizer or memory sanitizer. Avoid discarding names when those
sanitizers are enabled, unless explicitly requested to do otherwise.
---
 src/librustc/session/mod.rs                           | 10 +++++++++-
 src/test/run-make-fulldeps/sanitizer-address/Makefile |  3 +++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 9d60221fa3d75..fa2902e4f0ede 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -7,7 +7,7 @@ use rustc_data_structures::fingerprint::Fingerprint;
 
 use crate::lint;
 use crate::lint::builtin::BuiltinLintDiagnostics;
-use crate::session::config::{OutputType, PrintRequest, SwitchWithOptPath};
+use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
 use crate::session::search_paths::{PathKind, SearchPath};
 use crate::util::nodemap::{FxHashMap, FxHashSet};
 use crate::util::common::{duration_to_secs_str, ErrorReported};
@@ -626,6 +626,14 @@ impl Session {
             .output_types
             .contains_key(&OutputType::LlvmAssembly)
             || self.opts.output_types.contains_key(&OutputType::Bitcode);
+
+        // Address sanitizer and memory sanitizer use alloca name when reporting an issue.
+        let more_names = match self.opts.debugging_opts.sanitizer {
+            Some(Sanitizer::Address) => true,
+            Some(Sanitizer::Memory) => true,
+            _ => more_names,
+        };
+
         self.opts.debugging_opts.fewer_names || !more_names
     }
 
diff --git a/src/test/run-make-fulldeps/sanitizer-address/Makefile b/src/test/run-make-fulldeps/sanitizer-address/Makefile
index 51d8a4a947adc..3a377c32993d5 100644
--- a/src/test/run-make-fulldeps/sanitizer-address/Makefile
+++ b/src/test/run-make-fulldeps/sanitizer-address/Makefile
@@ -24,4 +24,7 @@ endif
 
 all:
 	$(RUSTC) -g -Z sanitizer=address -Z print-link-args $(EXTRA_RUSTFLAG) overflow.rs | $(CGREP) librustc_asan
+	# Verify that stack buffer overflow is detected:
 	$(TMPDIR)/overflow 2>&1 | $(CGREP) stack-buffer-overflow
+	# Verify that variable name is included in address sanitizer report:
+	$(TMPDIR)/overflow 2>&1 | $(CGREP) "'xs'"