[AIX][TLS] Diagnose use of unimplemented TLS models

Add front end diagnostics to report error for unimplemented TLS models set by
- compiler option `-ftls-model`
- attributes like `__thread int __attribute__((tls_model("local-exec"))) var_name;`

Reviewed by: aaron.ballman, nemanjai, PowerPC

Differential Revision: https://reviews.llvm.org/D102070

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 4b0bd30..0c5066a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1808,6 +1808,14 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
     Opts.ExplicitEmulatedTLS = true;
   }
 
+  if (Arg *A = Args.getLastArg(OPT_ftlsmodel_EQ)) {
+    if (T.isOSAIX()) {
+      StringRef Name = A->getValue();
+      if (Name != "global-dynamic")
+        Diags.Report(diag::err_aix_unsupported_tls_model) << Name;
+    }
+  }
+
   if (Arg *A = Args.getLastArg(OPT_fdenormal_fp_math_EQ)) {
     StringRef Val = A->getValue();
     Opts.FPDenormalMode = llvm::parseDenormalFPAttribute(Val);