From: Zachary Turner <zturner@google.com>
Date: Thu, 22 Sep 2016 15:55:05 +0000 (+0000)
Subject: Speculative fix for build failures due to consumeInteger.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=20bb0322fd381dd7e265eaa05b7fb1c292278abe;p=llvm

Speculative fix for build failures due to consumeInteger.

A recent patch added support for consumeInteger() and made
getAsInteger delegate to this function.  A few buildbots are
failing as a result with an assertion failure.  On a hunch,
I tested what happens if I call getAsInteger() on an empty
string, and sure enough it crashes the same way that the
buildbots are crashing.

I confirmed that getAsInteger() on an empty string did not
crash before my patch, so I suspect this to be the cause.

I also added a unit test for the empty string.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282170 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp
index 7503fac240a..51e0394d8bd 100644
--- a/lib/Support/StringRef.cpp
+++ b/lib/Support/StringRef.cpp
@@ -351,6 +351,9 @@ size_t StringRef::count(StringRef Str) const {
 }
 
 static unsigned GetAutoSenseRadix(StringRef &Str) {
+  if (Str.empty())
+    return 10;
+
   if (Str.startswith("0x") || Str.startswith("0X")) {
     Str = Str.substr(2);
     return 16;
diff --git a/unittests/ADT/StringRefTest.cpp b/unittests/ADT/StringRefTest.cpp
index 4249f231481..40ab4e038b8 100644
--- a/unittests/ADT/StringRefTest.cpp
+++ b/unittests/ADT/StringRefTest.cpp
@@ -571,7 +571,8 @@ TEST(StringRefTest, getAsInteger) {
 
 
 static const char* BadStrings[] = {
-    "18446744073709551617"  // value just over max
+    ""                      // empty string
+  , "18446744073709551617"  // value just over max
   , "123456789012345678901" // value way too large
   , "4t23v"                 // illegal decimal characters
   , "0x123W56"              // illegal hex characters