[NVPTX] Make ctor/dtor lowering always enabled in NVPTX (#126544)

Summary:
Currently we conditionally enable NVPTX lowering depending on the
language (C/C++/OpenMP). Unfortunately this causes problems because this
option is only present if the backend was enabled, which causes this to
error if you try to make LLVM-IR.

This patch instead makes it the only accepted lowering. The reason we
had it as opt-in before is because it is not handled by CUDA. So, this
pach also introduces diagnostics to prevent *all* creation of
device-side global constructors and destructors. We already did this for
variables, now we do it for attributes as well.

This inverts the responsibility of blocking this from the backend to the
langauage like it should be given that support for this is language
dependent.

1 files changed, 0 insertions, 21 deletions

diff --git a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index ad14338..68a0f4c 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -91,11 +91,6 @@
 
 using namespace llvm;
 
-static cl::opt<bool>
-    LowerCtorDtor("nvptx-lower-global-ctor-dtor",
-                  cl::desc("Lower GPU ctor / dtors to globals on the device."),
-                  cl::init(false), cl::Hidden);
-
 #define DEPOTNAME "__local_depot"
 
 /// DiscoverDependentGlobals - Return a set of GlobalVariables on which \p V
@@ -794,22 +789,6 @@ bool NVPTXAsmPrinter::doInitialization(Module &M) {
   if (M.alias_size() && (STI.getPTXVersion() < 63 || STI.getSmVersion() < 30))
     report_fatal_error(".alias requires PTX version >= 6.3 and sm_30");
 
-  // OpenMP supports NVPTX global constructors and destructors.
-  bool IsOpenMP = M.getModuleFlag("openmp") != nullptr;
-
-  if (!isEmptyXXStructor(M.getNamedGlobal("llvm.global_ctors")) &&
-      !LowerCtorDtor && !IsOpenMP) {
-    report_fatal_error(
-        "Module has a nontrivial global ctor, which NVPTX does not support.");
-    return true;  // error
-  }
-  if (!isEmptyXXStructor(M.getNamedGlobal("llvm.global_dtors")) &&
-      !LowerCtorDtor && !IsOpenMP) {
-    report_fatal_error(
-        "Module has a nontrivial global dtor, which NVPTX does not support.");
-    return true;  // error
-  }
-
   // We need to call the parent's one explicitly.
   bool Result = AsmPrinter::doInitialization(M);