[CUDA] Die if we ask the NVPTX backend to emit a global ctor/dtor.

Summary: Previously we'd just silently skip these.

Reviewers: tra, jholewinski

Subscribers: llvm-commits, jhen, echristo,

Differential Revision: http://reviews.llvm.org/D16739

llvm-svn: 259279

4 files changed, 40 insertions, 0 deletions

diff --git a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index ebeeedaec69..37ee942b4cc 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -802,6 +802,13 @@ void NVPTXAsmPrinter::recordAndEmitFilenames(Module &M) {
   }
 }
 
+static bool isEmptyXXStructor(GlobalVariable *GV) {
+  if (!GV) return true;
+  const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
+  if (!InitList) return true;  // Not an array; we don't know how to parse.
+  return InitList->getNumOperands() == 0;
+}
+
 bool NVPTXAsmPrinter::doInitialization(Module &M) {
   // Construct a default subtarget off of the TargetMachine defaults. The
   // rest of NVPTX isn't friendly to change subtargets per function and
@@ -816,6 +823,16 @@ bool NVPTXAsmPrinter::doInitialization(Module &M) {
     report_fatal_error("Module has aliases, which NVPTX does not support.");
     return true; // error
   }
+  if (!isEmptyXXStructor(M.getNamedGlobal("llvm.global_ctors"))) {
+    report_fatal_error(
+        "Module has a nontrivial global ctor, which NVPTX does not support.");
+    return true;  // error
+  }
+  if (!isEmptyXXStructor(M.getNamedGlobal("llvm.global_dtors"))) {
+    report_fatal_error(
+        "Module has a nontrivial global dtor, which NVPTX does not support.");
+    return true;  // error
+  }
 
   SmallString<128> Str1;
   raw_svector_ostream OS1(Str1);
diff --git a/llvm/test/CodeGen/NVPTX/global-ctor-empty.ll b/llvm/test/CodeGen/NVPTX/global-ctor-empty.ll
new file mode 100644
index 00000000000..10ca0168b30
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/global-ctor-empty.ll
@@ -0,0 +1,5 @@
+; RUN: llc < %s -march=nvptx -mcpu=sm_20 2>&1
+
+; Check that llc doesn't die when given an empty global ctor / dtor.
+@llvm.global_ctors = appending global [0 x { i32, void ()*, i8* }] []
+@llvm.global_dtors = appending global [0 x { i32, void ()*, i8* }] []
diff --git a/llvm/test/CodeGen/NVPTX/global-ctor.ll b/llvm/test/CodeGen/NVPTX/global-ctor.ll
new file mode 100644
index 00000000000..89155db08ea
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/global-ctor.ll
@@ -0,0 +1,9 @@
+; RUN: not llc < %s -march=nvptx -mcpu=sm_20 2>&1 | FileCheck %s
+
+; Check that llc dies when given a nonempty global ctor.
+@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @foo, i8* null }]
+
+; CHECK: ERROR: Module has a nontrivial global ctor
+define internal void @foo() {
+  ret void
+}
diff --git a/llvm/test/CodeGen/NVPTX/global-dtor.ll b/llvm/test/CodeGen/NVPTX/global-dtor.ll
new file mode 100644
index 00000000000..9d01f9bd387
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/global-dtor.ll
@@ -0,0 +1,9 @@
+; RUN: not llc < %s -march=nvptx -mcpu=sm_20 2>&1 | FileCheck %s
+
+; Check that llc dies when given a nonempty global dtor.
+@llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @foo, i8* null }]
+
+; CHECK: ERROR: Module has a nontrivial global dtor
+define internal void @foo() {
+  ret void
+}