Put more stuff in the comdat used for variables with static init.

Clang can already handle

-------------------------------------------
struct S {
  static const int x;
};
template<typename T> struct U {
  static const int k;
};
template<typename T> const int U<T>::k = T::x;

const int S::x = 42;
extern const int *f();
const int *g() { return &U<S>::k; }
int main() {
  return *f() + U<S>::k;
}

const int *f() { return &U<S>::k; }
-------------------------------------------

since r217264 which puts the .inint_array section in the same COMDAT
as the variable.

This patch allows the linker to more easily delete some dead code and data by
putting the guard variable and init function in the same COMDAT.

llvm-svn: 218089

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 9bf1dbbd0d8..cca825c1c56 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -6868,6 +6868,14 @@ static bool getTypeString(SmallStringEnc &Enc, const Decl *D,
 // Driver code
 //===----------------------------------------------------------------------===//
 
+const llvm::Triple &CodeGenModule::getTriple() const {
+  return getTarget().getTriple();
+}
+
+bool CodeGenModule::supportsCOMDAT() const {
+  return !getTriple().isOSBinFormatMachO();
+}
+
 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
   if (TheTargetCodeGenInfo)
     return *TheTargetCodeGenInfo;