[Support] - Fix possible crash in match() of llvm::Regex.

Crash was possible if match() method
was called on object that was moved or object
created with empty constructor.

Testcases updated.

DIfferential revision: https://reviews.llvm.org/D24123

llvm-svn: 280473

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Support/Regex.cpp b/llvm/lib/Support/Regex.cpp
index 35641f3b7cb..68ba79e1176 100644
--- a/llvm/lib/Support/Regex.cpp
+++ b/llvm/lib/Support/Regex.cpp
@@ -34,6 +34,13 @@ Regex::Regex(StringRef regex, unsigned Flags) {
   error = llvm_regcomp(preg, regex.data(), flags|REG_PEND);
 }
 
+Regex::Regex(Regex &&regex) {
+  preg = regex.preg;
+  error = regex.error;
+  regex.preg = nullptr;
+  regex.error = REG_BADPAT;
+}
+
 Regex::~Regex() {
   if (preg) {
     llvm_regfree(preg);
@@ -59,6 +66,9 @@ unsigned Regex::getNumMatches() const {
 }
 
 bool Regex::match(StringRef String, SmallVectorImpl<StringRef> *Matches){
+  if (error)
+    return false;
+
   unsigned nmatch = Matches ? preg->re_nsub+1 : 0;
 
   // pmatch needs to have at least one element.