#include "gen/inlineir.h"
#include "gen/llvmhelpers.h"

#include "declaration.h"
#include "template.h"
#include "gen/irstate.h"
#include "gen/tollvm.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/SourceMgr.h"
#if LDC_LLVM_VER >= 305
#include "llvm/AsmParser/Parser.h"
#include "llvm/Linker/Linker.h"
#else
#include "llvm/Assembly/Parser.h"
#include "llvm/Linker.h"
#endif

llvm::Function* DtoInlineIRFunction(FuncDeclaration* fdecl)
{
    const char* mangled_name = mangleExact(fdecl);
    TemplateInstance* tinst = fdecl->parent->isTemplateInstance();
    assert(tinst);

    Objects& objs = tinst->tdtypes;
    assert(objs.dim == 3);

    Expression* a0 = isExpression(objs[0]);
    assert(a0);
    StringExp* strexp = a0->toStringExp();
    assert(strexp);
    assert(strexp->sz == 1);
    std::string code(static_cast<char*>(strexp->string), strexp->len);

    Type* ret = isType(objs[1]);
    assert(ret);

    Tuple* a2 = isTuple(objs[2]);
    assert(a2);
    Objects& arg_types = a2->objects;

    std::string str;
    llvm::raw_string_ostream stream(str);
    stream << "define " << *DtoType(ret) << " @" << mangled_name << "(";

    for(size_t i = 0; ;)
    {
        Type* ty = isType(arg_types[i]);
        //assert(ty);
        if(!ty)
        {
            error(tinst->loc,
                "All parameters of a template defined with pragma llvm_inline_ir, except for the first one, should be types");
            fatal();
        }
        stream << *DtoType(ty);

        i++;
        if(i >= arg_types.dim)
            break;

        stream << ", ";
    }

    if(ret->ty == Tvoid)
        code.append("\nret void");

    stream << ")\n{\n" << code <<  "\n}";

    llvm::SMDiagnostic err;

#if LDC_LLVM_VER >= 306
    std::unique_ptr<llvm::Module> m = llvm::parseAssemblyString(
        stream.str().c_str(), err, gIR->context());
#elif LDC_LLVM_VER >= 303
    llvm::Module* m = llvm::ParseAssemblyString(
        stream.str().c_str(), NULL, err, gIR->context());
#else
    llvm::ParseAssemblyString(
        stream.str().c_str(), &gIR->module, err, gIR->context());
#endif

    std::string errstr = err.getMessage();
    if(errstr != "")
        error(tinst->loc,
            "can't parse inline LLVM IR:\n%s\n%s\n%s\nThe input string was: \n%s",
#if LDC_LLVM_VER >= 303
            err.getLineContents().str().c_str(),
#else
            err.getLineContents().c_str(),
#endif
            (std::string(err.getColumnNo(), ' ') + '^').c_str(),
            errstr.c_str(), stream.str().c_str());

#if LDC_LLVM_VER >= 306
    llvm::Linker(&gIR->module).linkInModule(m.get());
#elif LDC_LLVM_VER >= 303
    std::string errstr2 = "";
    llvm::Linker(&gIR->module).linkInModule(m, &errstr2);
    if(errstr2 != "")
        error(tinst->loc,
            "Error when linking in llvm inline ir: %s", errstr2.c_str());
#endif

    LLFunction* fun = gIR->module.getFunction(mangled_name);
    fun->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
    SET_COMDAT(fun, gIR->module);
    fun->addFnAttr(LDC_ATTRIBUTE(AlwaysInline));
    return fun;
}