[PATCH] Add compiler support for dynamic Asan runtime

[Alexey Samsonov]

  Please rebase the patch before uploading the next diff.


================
Comment at: lib/Driver/Tools.cpp:1873
@@ -1860,3 +1872,3 @@
   } else {
-    if (!Args.hasArg(options::OPT_shared))
-      addSanitizerRTLinkFlags(TC, Args, CmdArgs, "asan", true);
+    bool Executable = !Args.hasArg(options::OPT_shared);
+
----------------
The logic is still non-understandable. Please find a better way to express it. As a suggestion:

  if (NeedsSharedRT) {
    // add asan-dynamic.so to the link line.
  }
  if (Args.hasArg(options::OPT_shared)) {
    return;  // don't link static parts into shared objects.
  }
  StringRef AsanStaticPart = NeedsSharedRT ? "asan-preinit" : "asan";
  bool BeforeLibStdCXX = true;
  bool ExportSymbols = !NeedsSharedRT;
  addSanitizerRTLinkFlags(TC, Args, CmdArgs, AsanStaticPart, BeforeLibStdCXX, ExportSymbols);

now, if you don't want do add "-ldl lpthread -lrt -lm" to the link line for executable and -shared-libasan mode, you may add one more
flag to control whether you add these libs or not. Or, as an alternative, factor adding "-ldl ..." to a separate function and call it when necessary.



http://llvm-reviews.chandlerc.com/D3043