1 files changed, 166 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/OcamlGCPrinter.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/OcamlGCPrinter.cpp
new file mode 100644
index 000000000000..98177c0ba1cf
--- /dev/null
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/OcamlGCPrinter.cpp
@@ -0,0 +1,166 @@
+//===-- OcamlGCPrinter.cpp - Ocaml frametable emitter ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements printing the assembly code for an Ocaml frametable.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GCs.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/GCMetadataPrinter.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Module.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Target/Mangler.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+#include <cctype>
+using namespace llvm;
+
+namespace {
+
+  class OcamlGCMetadataPrinter : public GCMetadataPrinter {
+  public:
+    void beginAssembly(AsmPrinter &AP);
+    void finishAssembly(AsmPrinter &AP);
+  };
+
+}
+
+static GCMetadataPrinterRegistry::Add<OcamlGCMetadataPrinter>
+Y("ocaml", "ocaml 3.10-compatible collector");
+
+void llvm::linkOcamlGCPrinter() { }
+
+static void EmitCamlGlobal(const Module &M, AsmPrinter &AP, const char *Id) {
+  const std::string &MId = M.getModuleIdentifier();
+
+  std::string SymName;
+  SymName += "caml";
+  size_t Letter = SymName.size();
+  SymName.append(MId.begin(), std::find(MId.begin(), MId.end(), '.'));
+  SymName += "__";
+  SymName += Id;
+
+  // Capitalize the first letter of the module name.
+  SymName[Letter] = toupper(SymName[Letter]);
+
+  SmallString<128> TmpStr;
+  AP.Mang->getNameWithPrefix(TmpStr, SymName);
+
+  MCSymbol *Sym = AP.OutContext.GetOrCreateSymbol(TmpStr);
+
+  AP.OutStreamer.EmitSymbolAttribute(Sym, MCSA_Global);
+  AP.OutStreamer.EmitLabel(Sym);
+}
+
+void OcamlGCMetadataPrinter::beginAssembly(AsmPrinter &AP) {
+  AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getTextSection());
+  EmitCamlGlobal(getModule(), AP, "code_begin");
+
+  AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getDataSection());
+  EmitCamlGlobal(getModule(), AP, "data_begin");
+}
+
+/// emitAssembly - Print the frametable. The ocaml frametable format is thus:
+///
+///   extern "C" struct align(sizeof(intptr_t)) {
+///     uint16_t NumDescriptors;
+///     struct align(sizeof(intptr_t)) {
+///       void *ReturnAddress;
+///       uint16_t FrameSize;
+///       uint16_t NumLiveOffsets;
+///       uint16_t LiveOffsets[NumLiveOffsets];
+///     } Descriptors[NumDescriptors];
+///   } caml${module}__frametable;
+///
+/// Note that this precludes programs from stack frames larger than 64K
+/// (FrameSize and LiveOffsets would overflow). FrameTablePrinter will abort if
+/// either condition is detected in a function which uses the GC.
+///
+void OcamlGCMetadataPrinter::finishAssembly(AsmPrinter &AP) {
+  unsigned IntPtrSize = AP.TM.getDataLayout()->getPointerSize();
+
+  AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getTextSection());
+  EmitCamlGlobal(getModule(), AP, "code_end");
+
+  AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getDataSection());
+  EmitCamlGlobal(getModule(), AP, "data_end");
+
+  // FIXME: Why does ocaml emit this??
+  AP.OutStreamer.EmitIntValue(0, IntPtrSize);
+
+  AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getDataSection());
+  EmitCamlGlobal(getModule(), AP, "frametable");
+
+  int NumDescriptors = 0;
+  for (iterator I = begin(), IE = end(); I != IE; ++I) {
+    GCFunctionInfo &FI = **I;
+    for (GCFunctionInfo::iterator J = FI.begin(), JE = FI.end(); J != JE; ++J) {
+      NumDescriptors++;
+    }
+  }
+
+  if (NumDescriptors >= 1<<16) {
+    // Very rude!
+    report_fatal_error(" Too much descriptor for ocaml GC");
+  }
+  AP.EmitInt16(NumDescriptors);
+  AP.EmitAlignment(IntPtrSize == 4 ? 2 : 3);
+
+  for (iterator I = begin(), IE = end(); I != IE; ++I) {
+    GCFunctionInfo &FI = **I;
+
+    uint64_t FrameSize = FI.getFrameSize();
+    if (FrameSize >= 1<<16) {
+      // Very rude!
+      report_fatal_error("Function '" + FI.getFunction().getName() +
+                         "' is too large for the ocaml GC! "
+                         "Frame size " + Twine(FrameSize) + ">= 65536.\n"
+                         "(" + Twine(uintptr_t(&FI)) + ")");
+    }
+
+    AP.OutStreamer.AddComment("live roots for " +
+                              Twine(FI.getFunction().getName()));
+    AP.OutStreamer.AddBlankLine();
+
+    for (GCFunctionInfo::iterator J = FI.begin(), JE = FI.end(); J != JE; ++J) {
+      size_t LiveCount = FI.live_size(J);
+      if (LiveCount >= 1<<16) {
+        // Very rude!
+        report_fatal_error("Function '" + FI.getFunction().getName() +
+                           "' is too large for the ocaml GC! "
+                           "Live root count "+Twine(LiveCount)+" >= 65536.");
+      }
+
+      AP.OutStreamer.EmitSymbolValue(J->Label, IntPtrSize);
+      AP.EmitInt16(FrameSize);
+      AP.EmitInt16(LiveCount);
+
+      for (GCFunctionInfo::live_iterator K = FI.live_begin(J),
+                                         KE = FI.live_end(J); K != KE; ++K) {
+        if (K->StackOffset >= 1<<16) {
+          // Very rude!
+          report_fatal_error(
+                 "GC root stack offset is outside of fixed stack frame and out "
+                 "of range for ocaml GC!");
+        }
+        AP.EmitInt16(K->StackOffset);
+      }
+
+      AP.EmitAlignment(IntPtrSize == 4 ? 2 : 3);
+    }
+  }
+}