1 files changed, 57 insertions, 0 deletions
diff --git a/clang/lib/Driver/ToolChains/PPCLinux.cpp b/clang/lib/Driver/ToolChains/PPCLinux.cpp
index af2e3a21a0af..e480d8bd8703 100644
--- a/clang/lib/Driver/ToolChains/PPCLinux.cpp
+++ b/clang/lib/Driver/ToolChains/PPCLinux.cpp
@@ -8,11 +8,51 @@
 
 #include "PPCLinux.h"
 #include "clang/Driver/Driver.h"
+#include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Options.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 
+using namespace clang::driver;
 using namespace clang::driver::toolchains;
 using namespace llvm::opt;
+using namespace llvm::sys;
+
+// Glibc older than 2.32 doesn't fully support IEEE float128. Here we check
+// glibc version by looking at dynamic linker name.
+static bool GlibcSupportsFloat128(const std::string &Linker) {
+  llvm::SmallVector<char, 16> Path;
+
+  // Resolve potential symlinks to linker.
+  if (fs::real_path(Linker, Path))
+    return false;
+  llvm::StringRef LinkerName =
+      path::filename(llvm::StringRef(Path.data(), Path.size()));
+
+  // Since glibc 2.34, the installed .so file is not symlink anymore. But we can
+  // still safely assume it's newer than 2.32.
+  if (LinkerName.startswith("ld64.so"))
+    return true;
+
+  if (!LinkerName.startswith("ld-2."))
+    return false;
+  unsigned Minor = (LinkerName[5] - '0') * 10 + (LinkerName[6] - '0');
+  if (Minor < 32)
+    return false;
+
+  return true;
+}
+
+PPCLinuxToolChain::PPCLinuxToolChain(const Driver &D,
+                                     const llvm::Triple &Triple,
+                                     const llvm::opt::ArgList &Args)
+    : Linux(D, Triple, Args) {
+  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ)) {
+    StringRef ABIName = A->getValue();
+    if (ABIName == "ieeelongdouble" && !SupportIEEEFloat128(D, Triple, Args))
+      D.Diag(diag::warn_drv_unsupported_float_abi_by_lib) << ABIName;
+  }
+}
 
 void PPCLinuxToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                                   ArgStringList &CC1Args) const {
@@ -26,3 +66,20 @@ void PPCLinuxToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 
   Linux::AddClangSystemIncludeArgs(DriverArgs, CC1Args);
 }
+
+bool PPCLinuxToolChain::SupportIEEEFloat128(
+    const Driver &D, const llvm::Triple &Triple,
+    const llvm::opt::ArgList &Args) const {
+  if (!Triple.isLittleEndian() || !Triple.isPPC64())
+    return false;
+
+  if (Args.hasArg(options::OPT_nostdlib, options::OPT_nostdlibxx))
+    return true;
+
+  bool HasUnsupportedCXXLib =
+      ToolChain::GetCXXStdlibType(Args) == CST_Libcxx &&
+      GCCInstallation.getVersion().isOlderThan(12, 1, 0);
+
+  return GlibcSupportsFloat128(Linux::getDynamicLinker(Args)) &&
+         !(D.CCCIsCXX() && HasUnsupportedCXXLib);
+}