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Remove unnecessary in C++11 c_str() calls 

While theoratically required in pre-C++11 to avoid re-allocation upon call,
C++11 guarantees that c_str() returns a pointer to the internal array so
pre-calling c_str() is no longer required.

llvm-svn: 242983
This commit is contained in:
Yaron Keren 2015-07-23 05:49:29 +00:00
parent 6a3fdeca22
commit 4135e4c475
1 changed files with 1 additions and 18 deletions
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19
llvm/lib/Support/Unix/Signals.inc
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@ -144,9 +144,6 @@ static void RemoveFilesToRemove() {
// memory.
std::vector<std::string>& FilesToRemoveRef = *FilesToRemove;
for (unsigned i = 0, e = FilesToRemoveRef.size(); i != e; ++i) {
// We rely on a std::string implementation for which repeated calls to
// 'c_str()' don't allocate memory. We pre-call 'c_str()' on all of these
// strings to try to ensure this is safe.
const char *path = FilesToRemoveRef[i].c_str();
// Get the status so we can determine if it's a file or directory. If we
@ -231,21 +228,7 @@ bool llvm::sys::RemoveFileOnSignal(StringRef Filename,
std::string* ErrMsg) {
{
sys::SmartScopedLock<true> Guard(*SignalsMutex);
std::vector<std::string>& FilesToRemoveRef = *FilesToRemove;
std::string *OldPtr =
FilesToRemoveRef.empty() ? nullptr : &FilesToRemoveRef[0];
FilesToRemoveRef.push_back(Filename);
// We want to call 'c_str()' on every std::string in this vector so that if
// the underlying implementation requires a re-allocation, it happens here
// rather than inside of the signal handler. If we see the vector grow, we
// have to call it on every entry. If it remains in place, we only need to
// call it on the latest one.
if (OldPtr == &FilesToRemoveRef[0])
FilesToRemoveRef.back().c_str();
else
for (unsigned i = 0, e = FilesToRemoveRef.size(); i != e; ++i)
FilesToRemoveRef[i].c_str();
FilesToRemove->push_back(Filename);
}
RegisterHandlers();