commit a4323a5cca42dfce15b1a63e934ea3d2ce5572de
author Shankar Easwaran <shankare@codeaurora.org> Fri Apr 05 03:50:15 2013 +0000
committer Shankar Easwaran <shankare@codeaurora.org> Fri Apr 05 03:50:15 2013 +0000
tree 243c19278d888ec7bdebd6c43bfc36c6b6e2271c
parent 95923058eb748facc764f52d5deb928a564c5038

This fixes a SIGSEGV failure in ReaderArchive while trying to trace what
InputFile is being pulled from the Archive library to resolve a symbol. 

The buffer which was being used was already being handed over to the
MemoryBuffer object and was being accessed after the hand over. 

Moving it before the buffer is handed over.

llvm-svn: 178838

lld/lib/ReaderWriter/ELF/ELFTargetInfo.cpp

diff --git a/lld/lib/ReaderWriter/ELF/ELFTargetInfo.cpp b/lld/lib/ReaderWriter/ELF/ELFTargetInfo.cpp
index 338096d..577f5a8 100644
--- a/lld/lib/ReaderWriter/ELF/ELFTargetInfo.cpp
+++ b/lld/lib/ReaderWriter/ELF/ELFTargetInfo.cpp
@@ -67,7 +67,7 @@
       _entrySymbolName = "_start";
     }
   }
-  
+
   if (_inputFiles.empty()) {
     diagnostics << "No input files\n";
     return true;
@@ -144,14 +144,31 @@
 }
 
 bool ELFTargetInfo::appendLibrary(StringRef libName) {
-  SmallString<128> fullPath;
+  bool foundFile = false;
+  StringRef pathref;
   for (StringRef dir : _inputSearchPaths) {
-    // FIXME: need to handle other extensions, like .so
-    fullPath.assign(dir);
-    llvm::sys::path::append(fullPath, Twine("lib") + libName + ".a");
-    StringRef pathref = fullPath.str();
-    unsigned pathlen = pathref.size();
-    if (llvm::sys::fs::exists(pathref)) {
+    // Search for dynamic library
+    if (!_isStaticExecutable) {
+      SmallString<128> dynlibPath;
+      dynlibPath.assign(dir);
+      llvm::sys::path::append(dynlibPath, Twine("lib") + libName + ".so");
+      pathref = dynlibPath.str();
+      if (llvm::sys::fs::exists(pathref)) {
+        foundFile = true;
+      }
+    }
+    // Search for static libraries too
+    if (!foundFile) {
+      SmallString<128> archivefullPath;
+      archivefullPath.assign(dir);
+      llvm::sys::path::append(archivefullPath, Twine("lib") + libName + ".a");
+      pathref = archivefullPath.str();
+      if (llvm::sys::fs::exists(pathref)) {
+        foundFile = true;
+      }
+    }
+    if (foundFile) {
+      unsigned pathlen = pathref.size();
       char *x = _extraStrings.Allocate<char>(pathlen);
       memcpy(x, pathref.data(), pathlen);
       appendInputFile(StringRef(x,pathlen));

lld/lib/ReaderWriter/ReaderArchive.cpp

diff --git a/lld/lib/ReaderWriter/ReaderArchive.cpp b/lld/lib/ReaderWriter/ReaderArchive.cpp
index d3287dd..1928e2f 100644
--- a/lld/lib/ReaderWriter/ReaderArchive.cpp
+++ b/lld/lib/ReaderWriter/ReaderArchive.cpp
@@ -45,9 +45,9 @@
     OwningPtr<MemoryBuffer> buff;
     if (ci->getMemoryBuffer(buff, true))
       return nullptr;
-    std::unique_ptr<MemoryBuffer> mb(buff.take());
     if (_targetInfo.logInputFiles())
       llvm::outs() << buff->getBufferIdentifier() << "\n";
+    std::unique_ptr<MemoryBuffer> mb(buff.take());
     if (_targetInfo.parseFile(mb, result))
       return nullptr;
 
@@ -153,7 +153,7 @@
     }
   }
 
-  std::unordered_map<StringRef, 
+  std::unordered_map<StringRef,
                      llvm::object::Archive::child_iterator> _symbolMemberMap;
 }; // class FileArchive