/*

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of JITCraft.

  *

  * JITCraft is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * JITCraft. If not, see http://www.gnu.org/licenses/.

  */

 #include <stdio.h>

 #include "../Zone.h"

 #include "../Interpreter.h"

 #include "Scanner.h"

 #include "CompileContext.h"

 #include "Parser.h"

 #include "NameBinding.h"

 #include "SemanticAnalysis.h"

 #include "../Spaces-inl.h"

 #include "../Heap-inl.h"

 using namespace ke;

 CompileContext::CompileContext(Zone *zone, const char *file)

   : zone_(zone),

     failures_(0),

     file_(file)

 {

 }

 CompileContext::~CompileContext()

 {

     if (failures_)

         zone_->endCompilationErrors();

 }

 bool

 CompileContext::addTranslationUnit(TranslationUnit *unit)

 {

     if (!units_.append(unit))

         return false;

     if (!unparsed_.append(unit))

         return false;

     return true;

 }

 char *

 CompileContext::loadSource(const char *file, size_t *lengthp)

 {

     char *bytes = NULL;

     size_t length;

     FILE *fp = fopen(file, "rb");

     if (!fp) {

         reportError(SourcePosition(), Message_CantOpenFile);

         return NULL;

     }

     if (fseek(fp, 0, SEEK_END)) {

         reportError(SourcePosition(), Message_ErrorSeekingFile);

         fclose(fp);

         return NULL;

     }

     long size = ftell(fp);

     if (size < 0) {

         reportError(SourcePosition(), Message_ErrorSeekingFile);

         fclose(fp);

         return NULL;

     }

     rewind(fp);

     length = size_t(size);

     bytes = new char[length + 1];

     if (fread(bytes, 1, length, fp) != length) {

         reportError(SourcePosition(), Message_ErrorReadingFile);

         fclose(fp);

         delete [] bytes;

         return NULL;

     }

     fclose(fp);

     *lengthp = length;

     return bytes;

 }

 bool

 CompileContext::parse(TranslationUnit *unit)

 {

     assert(!unit->tree_);

     size_t length;

     char *source = loadSource(unit->path_, &length);

     if (!source)

         return false;

     Parser parser(ZONE(), *this, source, length);

     if ((unit->tree_ = parser.parse()) == NULL)

         return false;

     return true;

 }

 bool

 CompileContext::evaluateImports(TranslationUnit *unit)

 {

     if (units_.length() > 1)

         return true;

 #if 0

     // For now we hardcode this...

     TranslationUnit *u2 = new (ZONE()->pool()) TranslationUnit();

     u2->path_ = "C:\\Users\\dvander\\jitcraft\\jitcraft-2\\src\\Debug\\wizard.sp";

     ImportStatement *stmt = unit->tree()->imports()->at(0)->toImportStatement();

     stmt->setImportSource(u2);

     if (!u2->dependents_.append(unit))

         return false;

     if (!addTranslationUnit(u2))

         return false;

 #endif

     return true;

 }

 bool

 CompileContext::propagateFailure()

 {

     Vector<TranslationUnit *> worklist;

     for (size_t i = 0; i < units_.length(); i++) {

         if (units_[i]->failed() && !worklist.append(units_[i]))

             return false;

     }

     while (!worklist.empty()) {

         TranslationUnit *unit = worklist.popCopy();

         for (size_t i = 0; i < unit->dependents().length(); i++) {

             TranslationUnit *other = unit->dependents().at(i);

             if (other->failed())

                 continue;

             other->failed_ = true;

             if (!worklist.append(other))

                 return false;

         }

     }

     return true;

 }

 bool

 CompileContext::compile()

 {

     // Phase 1. Parse all modules we're importing. This process may load new

     // modules off disk, and add them to the parse queue.

     while (!unparsed_.empty()) {

         TranslationUnit *unit = unparsed_.popCopy();

         if (!parse(unit))

             unit->failed_ = true;

         if (!evaluateImports(unit))

             unit->failed_ = true;

     }

     // Phase 2. Create scopes and symbol tables for every lexical region with

     // a declaration. This phase excludes declarations created via imports.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

         if (!PopulateNamesAndTypes(zone_, *this, unit))

             unit->failed_ = true;

     }

     // Phase 3. Complete imports and bind all names.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

         if (!BindNamesAndTypes(zone_, *this, unit))

             unit->failed_ = true;

     }

     // Phase 4. Assign types to every public name in the module.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

     }

     // Intermediate phase. Decide which modules we should not perform

     // semantic analysis on.

     if (!propagateFailure())

         return false;

     // Phase 4. Perform full semantic analysis on each module.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

     }

     // Intermediate phase. Propagate failure from semantic analysis.

     if (!propagateFailure())

         return false;

     // Phase 5. Now we can finally perform bytecode compilation.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

         SemanticAnalysis sema(zone_, *this, unit);

         sema.analyze();

     }

     // Phase 6. Run modules.

     for (size_t i = 0; i < units_.length(); i++) {

         TranslationUnit *unit = units_[i];

         if (unit->failed())

             continue;

         InvokeArgs args;

         if (!zone_->stack().pushModuleFrame(unit->module_, args))

             assert(false);

         if (failures_)

             return false;

         ke::LocalSlot slot;

         if (!Interpret(zone_, NULL, &slot))

             assert(false);

     }

     if (failures_)

         return false;

     return true;

 }

 void

 CompileContext::reportErrorVa(const SourcePosition &pos, Message msg, va_list ap)

 {

     if (!failures_)

         zone_->beginCompilationErrors(file_);

     zone_->reportCompilationError(msg, pos.line, pos.col, ap);

     failures_++;

 }

 void

 CompileContext::reportError(const SourcePosition &pos, Message msg, ...)

 {

     va_list ap;

     va_start(ap, msg);

     reportErrorVa(pos, msg, ap);

     va_end(ap);

 }