From 7faf7e50757dde2cb8583ee08ef31f4b8312e44f Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Thu, 5 Oct 2017 21:15:14 -0700
Subject: [PATCH] closes bpo-31696: don't mention GCC in sys.version when
 building with clang (#3891)

---
 .../2017-10-04-23-40-32.bpo-31696.Y3_aBV.rst      |  2 ++
 Python/getcompiler.c                              | 15 +++++++--------
 2 files changed, 9 insertions(+), 8 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Build/2017-10-04-23-40-32.bpo-31696.Y3_aBV.rst

diff --git a/Misc/NEWS.d/next/Build/2017-10-04-23-40-32.bpo-31696.Y3_aBV.rst b/Misc/NEWS.d/next/Build/2017-10-04-23-40-32.bpo-31696.Y3_aBV.rst
new file mode 100644
index 00000000000..00aae0b8ae1
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2017-10-04-23-40-32.bpo-31696.Y3_aBV.rst
@@ -0,0 +1,2 @@
+Improve compiler version information in :data:`sys.version` when Python is
+built with Clang.
diff --git a/Python/getcompiler.c b/Python/getcompiler.c
index 9d9c33ac2de..59c0dbf92ae 100644
--- a/Python/getcompiler.c
+++ b/Python/getcompiler.c
@@ -5,15 +5,14 @@
 
 #ifndef COMPILER
 
-#ifdef __GNUC__
+// Note the __clang__ conditional has to come before the __GNUC__ one because
+// clang pretends to be GCC.
+#if defined(__clang__)
+#define COMPILER "\n[Clang " __clang_version__ "]"
+#elif defined(__GNUC__)
 #define COMPILER "\n[GCC " __VERSION__ "]"
-#endif
-
-#endif /* !COMPILER */
-
-#ifndef COMPILER
-
-#ifdef __cplusplus
+// Generic fallbacks.
+#elif defined(__cplusplus)
 #define COMPILER "[C++]"
 #else
 #define COMPILER "[C]"