Initial Subzero WASM prototype.

src/IceCompiler.cpp

 //===- subzero/src/IceCompiler.cpp - Driver for bitcode translation -------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Defines a driver for translating PNaCl bitcode into native code.
 ///
 /// The driver can either directly parse the binary bitcode file, or use LLVM
 /// routines to parse a textual bitcode file into LLVM IR and then convert LLVM
 /// IR into ICE. In either case, the high-level ICE is then compiled down to
 /// native code, as either an ELF object file or a textual asm file.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceCompiler.h"
 
 #include "IceBuildDefs.h"
 #include "IceCfg.h"
 #include "IceClFlags.h"
 #include "IceClFlags.h"
 #include "IceConverter.h"
 #include "IceELFObjectWriter.h"
 #include "PNaClTranslator.h"
 
+#ifdef SUBZERO_WASM
+#include "WasmTranslator.h"
+#endif

[JF, 2016/03/28 18:17:13]

Why not put the #if in the other header?

[Eric Holk, 2016/03/29 19:54:08]

Done.

+
 #ifdef __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-parameter"
 #endif // __clang__
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Bitcode/NaCl/NaClReaderWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/StreamingMemoryObject.h"
 
 #ifdef __clang__
 #pragma clang diagnostic pop
 #endif // __clang__
 
 #include <regex>
 
 namespace Ice {
 
 namespace {
 
 bool llvmIRInput(const IceString &Filename) {
   return BuildDefs::llvmIrAsInput() &&
          std::regex_match(Filename, std::regex(".*\\.ll"));
 }
 
+bool wasmInput(const IceString &Filename) {
+  return BuildDefs::llvmIrAsInput() &&
+         std::regex_match(Filename, std::regex(".*\\.wasm"));

[JF, 2016/03/28 18:17:13]

Eek, I wouldn't use regex for this. It's a huge hammer. StringRef has
endswith().

[Eric Holk, 2016/03/29 19:54:08]

I just cargo-culted from the previous llvmIRInput function, although I agree
it's a bigger hammer than we need.

+}
+
 } // end of anonymous namespace
 
 void Compiler::run(const Ice::ClFlags &Flags, GlobalContext &Ctx,
                    std::unique_ptr<llvm::DataStreamer> &&InputStream) {
   // The Minimal build (specifically, when dump()/emit() are not implemented)
   // allows only --filetype=obj. Check here to avoid cryptic error messages
   // downstream.
   if (!BuildDefs::dump() && Ctx.getFlags().getOutFileType() != FT_Elf) {
     // TODO(stichnot): Access the actual command-line argument via
     // llvm::Option.ArgStr and .ValueStr .
     Ctx.getStrError()
         << "Error: only --filetype=obj is supported in this build.\n";
     Ctx.getErrorStatus()->assign(EC_Args);
     return;
   }
 
   TimerMarker T(Ice::TimerStack::TT_szmain, &Ctx);
 
   Ctx.emitFileHeader();
   Ctx.startWorkerThreads();
 
   std::unique_ptr<Translator> Translator;
   const IceString &IRFilename = Flags.getIRFilename();
-  const bool BuildOnRead = Flags.getBuildOnRead() && !llvmIRInput(IRFilename);
+  const bool BuildOnRead = Flags.getBuildOnRead() && !llvmIRInput(IRFilename) &&
+                           !wasmInput(IRFilename);
+  const bool WasmBuildOnRead = Flags.getBuildOnRead() && wasmInput(IRFilename);
   if (BuildOnRead) {
     std::unique_ptr<PNaClTranslator> PTranslator(new PNaClTranslator(&Ctx));
     std::unique_ptr<llvm::StreamingMemoryObject> MemObj(
         new llvm::StreamingMemoryObjectImpl(InputStream.release()));
     PTranslator->translate(IRFilename, std::move(MemObj));
     Translator.reset(PTranslator.release());
+  } else if (WasmBuildOnRead) {
+#ifdef SUBZERO_WASM

[Jim Stichnoth, 2016/03/29 17:49:57]

We try to minimize the use of #ifdef code.  Where possible, the code is
conditional on some Ice::BuildDefs constexpr function so that mistakes are
caught by the compiler in early development.

Would that be possible here?

[Eric Holk, 2016/03/29 22:58:07]

My latest update should have basically no #ifdef code anymore.

+    std::unique_ptr<WasmTranslator> WTranslator(new WasmTranslator(&Ctx));
+
+    WTranslator->translate(IRFilename, std::move(InputStream));
+
+    Translator.reset(WTranslator.release());
+#else
+      Ctx.getStrError()
+          << "WASM support not enabled\n";
+      Ctx.getErrorStatus()->assign(EC_Args);
+      return;
+#endif

[JF, 2016/03/28 18:17:13]

Would be nice if this switch were only visible from the WasmTranslator.h file:
WasmTranslator could just be a stub class which emits this error.

[Eric Holk, 2016/03/29 19:54:08]

Done.

   } else if (BuildDefs::llvmIr()) {
     if (BuildDefs::browser()) {
       Ctx.getStrError()
           << "non BuildOnRead is not supported w/ PNACL_BROWSER_TRANSLATOR\n";
       Ctx.getErrorStatus()->assign(EC_Args);
       return;
     }
     // Globals must be kept alive after lowering when converting from LLVM to
     // Ice.
     Ctx.setDisposeGlobalVariablesAfterLowering(false);
@@ skipping 44 matching lines @@
 
   if (Ctx.getFlags().getTimeEachFunction()) {
     constexpr bool NoDumpCumulative = false;
     Ctx.dumpTimers(GlobalContext::TSK_Funcs, NoDumpCumulative);
   }
   constexpr bool FinalStats = true;
   Ctx.dumpStats("_FINAL_", FinalStats);
 }
 
 } // end of namespace Ice