Add --unwindlib=[libgcc|compiler-rt] to parallel --rtlib= [take 2]

"clang++ hello.cc --rtlib=compiler-rt"

now can works without specifying additional unwind or exception
handling libraries.

This reworked version of the feature no longer modifies today's default
unwind library for compiler-rt: which is nothing. Rather, a user
can specify -DCLANG_DEFAULT_UNWINDLIB=libunwind when configuring
the compiler.

This should address the issues from the previous version.

Update tests for new --unwindlib semantics.

Differential Revision: https://reviews.llvm.org/D59109

llvm-svn: 356508

1 files changed, 27 insertions, 0 deletions

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 6b56271..5dff2b2 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -693,6 +693,33 @@ ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
   return GetDefaultRuntimeLibType();
 }
 
+ToolChain::UnwindLibType ToolChain::GetUnwindLibType(
+    const ArgList &Args) const {
+  const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
+  StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_UNWINDLIB;
+
+  if (LibName == "none")
+    return ToolChain::UNW_None;
+  else if (LibName == "platform" || LibName == "") {
+    ToolChain::RuntimeLibType RtLibType = GetRuntimeLibType(Args);
+    if (RtLibType == ToolChain::RLT_CompilerRT)
+      return ToolChain::UNW_None;
+    else if (RtLibType == ToolChain::RLT_Libgcc)
+      return ToolChain::UNW_Libgcc;
+  } else if (LibName == "libunwind") {
+    if (GetRuntimeLibType(Args) == RLT_Libgcc)
+      getDriver().Diag(diag::err_drv_incompatible_unwindlib);
+    return ToolChain::UNW_CompilerRT;
+  } else if (LibName == "libgcc")
+    return ToolChain::UNW_Libgcc;
+
+  if (A)
+    getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
+        << A->getAsString(Args);
+
+  return GetDefaultUnwindLibType();
+}
+
 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;