Add support for -mno-tls-direct-seg-refs to Clang
This patch exposes functionality added in rL344723 to the Clang driver/frontend
as a flag and adds appropriate metadata.
Driver tests pass:
```
ninja check-clang-driver
-snip-
Expected Passes : 472
Expected Failures : 3
Unsupported Tests : 65
```
Odd failure in CodeGen tests but unrelated to this:
```
ninja check-clang-codegen
-snip-
/SourceCache/llvm-trunk-8.0/tools/clang/test/CodeGen/builtins-wasm.c:87:10:
error: cannot compile this builtin function yet
-snip-
Failing Tests (1):
Clang :: CodeGen/builtins-wasm.c
Expected Passes : 1250
Expected Failures : 2
Unsupported Tests : 120
Unexpected Failures: 1
```
Original commit:
[X86] Support for the mno-tls-direct-seg-refs flag
Allows to disable direct TLS segment access (%fs or %gs). GCC supports a
similar flag, it can be useful in some circumstances, e.g. when a thread
context block needs to be updated directly from user space. More info and
specific use cases: https://bugs.llvm.org/show_bug.cgi?id=16145
Patch by nruslan (Ruslan Nikolaev).
Differential Revision: https://reviews.llvm.org/D53102
llvm-svn: 344739
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 322a02d..e15c9ad 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1739,6 +1739,10 @@
Args.hasArg(options::OPT_fapple_kext))
CmdArgs.push_back("-disable-red-zone");
+ if (!Args.hasFlag(options::OPT_mtls_direct_seg_refs,
+ options::OPT_mno_tls_direct_seg_refs, true))
+ CmdArgs.push_back("-mno-tls-direct-seg-refs");
+
// Default to avoid implicit floating-point for kernel/kext code, but allow
// that to be overridden with -mno-soft-float.
bool NoImplicitFloat = (Args.hasArg(options::OPT_mkernel) ||