[lld] r218083 - Fix buggy Twine storage in ELFLinkingContext::searchLibrary()

[Rui Ueyama]

Author: ruiu
Date: Thu Sep 18 17:05:37 2014
New Revision: 218083

URL: http://llvm.org/viewvc/llvm-project?rev=218083&view=rev
Log:
Fix buggy Twine storage in ELFLinkingContext::searchLibrary()

This patch fixes a forbidden use of Twine. It should only be used
as an intermediary value, but never stored.

This caused a bug in lld when running on Linux and compiled with
optimizations - it couldn't properly search libs.

Patch from Rafael Auler!

Modified:
    lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp

Modified: lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp?rev=218083&r1=218082&r2=218083&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp Thu Sep 18 17:05:37 2014
@@ -169,22 +169,22 @@ static void buildSearchPath(SmallString<
 
 ErrorOr<StringRef> ELFLinkingContext::searchLibrary(StringRef libName) const {
   bool hasColonPrefix = libName[0] == ':';
-  Twine soName =
-      hasColonPrefix ? libName.drop_front() : Twine("lib", libName) + ".so";
-  Twine archiveName =
-      hasColonPrefix ? libName.drop_front() : Twine("lib", libName) + ".a";
   SmallString<128> path;
   for (StringRef dir : _inputSearchPaths) {
     // Search for dynamic library
     if (!_isStaticExecutable) {
       buildSearchPath(path, dir, _sysrootPath);
-      llvm::sys::path::append(path, soName);
+      llvm::sys::path::append(path, hasColonPrefix
+                                        ? libName.drop_front()
+                                        : Twine("lib", libName) + ".so");
       if (llvm::sys::fs::exists(path.str()))
         return StringRef(*new (_allocator) std::string(path.str()));
     }
     // Search for static libraries too
     buildSearchPath(path, dir, _sysrootPath);
-    llvm::sys::path::append(path, archiveName);
+    llvm::sys::path::append(path, hasColonPrefix
+                                      ? libName.drop_front()
+                                      : Twine("lib", libName) + ".a");
     if (llvm::sys::fs::exists(path.str()))
       return StringRef(*new (_allocator) std::string(path.str()));
   }