//===- llvm/tools/gollvm/unittests/BackendCore/BackendNodeTests.cpp -----===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "go-llvm-bnode.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "operator.h"
#include "gtest/gtest.h"
#include "TestUtils.h"
#include "DiffUtils.h"

using namespace goBackendUnitTests;

namespace {

class SimpleVisitor {
 public:
  SimpleVisitor(unsigned stopAt = 0xffffffff) : stopAt_(stopAt) { }

  std::pair<VisitDisp, Bnode *> visitNodePre(Bnode *node) {
    ss_ << "node " << node->flavstr() << " pre " << id(node) << "\n";
    VisitDisp disp = (stopAt_ == id(node) ? StopWalk : ContinueWalk);
    return std::make_pair(disp, node);
  }
  std::pair<VisitDisp, Bnode *> visitNodePost(Bnode *node) {
    ss_ << "node " << node->flavstr() << " post " << id(node) << "\n";
    VisitDisp disp = (stopAt_ == id(node) ? StopWalk : ContinueWalk);
    return std::make_pair(disp, node);
  }

  std::pair< std::pair<VisitDisp, VisitChildDisp>, Bnode *>
  visitChildPre(Bnode *parent, Bnode *child) {
    ss_ << "pre child " << child->flavstr() << " " << id(parent) << " " << id(child) << "\n";
    VisitDisp disp = (stopAt_ == id(child) ? StopWalk : ContinueWalk);
    return std::make_pair(std::make_pair(disp, VisitChild), child);
  }
  std::pair<VisitDisp, Bnode *> visitChildPost(Bnode *parent, Bnode *child) {
    ss_ << "post child " << child->flavstr() << " " << id(parent) << " " << id(child) << "\n";
    VisitDisp disp = (stopAt_ == id(child) ? StopWalk : ContinueWalk);
    return std::make_pair(disp, child);
  }

  std::string str() const { return ss_.str(); }

  unsigned id(Bnode *node) {
    return node->id();
  }

 private:
  std::stringstream ss_;
  unsigned stopAt_;
};

TEST(BackendNodeTests, VerifyVisitorBehavior) {

  FcnTestHarness h("foo");
  Llvm_backend *be = h.be();
  Location loc;

  SimpleVisitor vis;

  Btype *bi32t = be->integer_type(false, 32);
  Btype *bpi32t = be->pointer_type(bi32t);
  Bexpression *c22 = mkInt32Const(be, 22);
  Bvariable *xv = h.mkLocal("x", bi32t);
  Bvariable *yv = h.mkLocal("y", bpi32t);
  Bexpression *ve = be->var_expression(xv, VE_rvalue, loc);
  Bexpression *add = be->binary_expression(OPERATOR_PLUS, c22, ve, loc);
  Bexpression *ve2 = be->var_expression(yv, VE_rvalue, loc);
  Bexpression *der = be->indirect_expression(bi32t, ve2, false, loc);
  Bexpression *sub = be->binary_expression(OPERATOR_MINUS, add, der, loc);
  Bexpression *matsub = be->materialize(sub);

  Bnode *res1 = update_walk_nodes(matsub, vis);

  EXPECT_EQ(res1, matsub);

  const char *exp = R"RAW_RESULT(
    node - pre 17
    pre child + 17 14
    node + pre 14
    pre child const 14 1
    node const pre 1
    node const post 1
    post child const 14 1
    pre child deref 14 13
    node deref pre 13
    pre child var 13 8
    node var pre 8
    node var post 8
    post child var 13 8
    node deref post 13
    post child deref 14 13
    node + post 14
    post child + 17 14
    pre child deref 17 16
    node deref pre 16
    pre child deref 16 15
    node deref pre 15
    pre child var 15 10
    node var pre 10
    node var post 10
    post child var 15 10
    node deref post 15
    post child deref 16 15
    node deref post 16
    post child deref 17 16
    node - post 17
    )RAW_RESULT";

  std::string reason;
  bool equal = difftokens(exp, vis.str(), reason);
  EXPECT_EQ("pass", equal ? "pass" : reason);
  if (!equal) {
    std::cerr << "expected dump:\n" << exp << "\n";
    std::cerr << "result dump:\n" << vis.str() << "\n";
  }

  h.mkExprStmt(matsub);

  bool broken = h.finish(PreserveDebugInfo);
  EXPECT_FALSE(broken && "Module failed to verify.");
}

TEST(BackendNodeTests, CloneSubtree) {

  FcnTestHarness h("foo");
  Llvm_backend *be = h.be();
  Location loc = h.loc();

  // (x - int32(z)) + *y
  Btype *bi16t = be->integer_type(false, 16);
  Btype *bi32t = be->integer_type(false, 32);
  Btype *bpi32t = be->pointer_type(bi32t);
  Bvariable *xv = h.mkLocal("x", bi32t);
  Bvariable *yv = h.mkLocal("y", bpi32t);
  Bvariable *zv = h.mkLocal("z", bi16t);
  Bexpression *vex = be->var_expression(xv, VE_rvalue, loc);
  Bexpression *vez = be->var_expression(zv, VE_rvalue, loc);
  Bexpression *conv = be->convert_expression(bi32t, vez, loc);
  Bexpression *sub = be->binary_expression(OPERATOR_PLUS, vex, conv, loc);
  Bexpression *vey = be->var_expression(yv, VE_rvalue, loc);
  Bexpression *der = be->indirect_expression(bi32t, vey, false, loc);
  Bexpression *add = be->binary_expression(OPERATOR_PLUS, sub, der, loc);
  Bexpression *matadd = be->materialize(add);
  Bexpression *matclone = be->nodeBuilder().cloneSubtree(matadd);
  EXPECT_NE(add, matclone);

  const char *exp = R"RAW_RESULT(
  %x.ld.0 = load i32, i32* %x
  %z.ld.0 = load i16, i16* %z
  %sext.0 = sext i16 %z.ld.0 to i32
  %add.0 = add i32 %x.ld.0, %sext.0
  %y.ld.0 = load i32*, i32** %y
  %.ld.0 = load i32, i32* %y.ld.0
  %add.1 = add i32 %add.0, %.ld.0
    )RAW_RESULT";

  bool isOK = h.expectRepr(matadd, exp);
  EXPECT_TRUE(isOK && "expr does not have expected contents");
  isOK = h.expectRepr(matclone, exp);
  EXPECT_TRUE(isOK && "cloned expr does not have expected contents");

  h.mkExprStmt(matadd);
  h.mkExprStmt(matclone);

  bool broken = h.finish(PreserveDebugInfo);
  EXPECT_FALSE(broken && "Module failed to verify.");

}

TEST(BackendNodeTests, FixSharing) {

  FcnTestHarness h("foo");
  Llvm_backend *be = h.be();
  Location loc = h.loc();

  Btype *bi32t = be->integer_type(false, 32);
  Btype *bpi32t = be->pointer_type(bi32t);
  Btype *s2t = mkBackendStruct(be, bpi32t, "f1", bi32t, "f2", nullptr);
  Btype *s4t = mkBackendStruct(be, s2t, "f1", s2t, "f2", nullptr);
  Bvariable *xv = h.mkLocal("x", s4t);

  // y = x.f1.f1 + x.f1.f1 [with sharing]
  Bexpression *vex = be->var_expression(xv, VE_rvalue, loc);
  Bexpression *f1ex = be->struct_field_expression(vex, 0, loc);
  Bexpression *f2ex = be->struct_field_expression(f1ex, 0, loc);
  Bexpression *der = be->indirect_expression(bi32t, f2ex, false, loc);
  Bexpression *add = be->binary_expression(OPERATOR_PLUS, der, der, loc);
  Bexpression *matadd = be->materialize(add);

  const char *exp2 = R"RAW_RESULT(
  %field.0 = getelementptr inbounds { { i32*, i32 }, { i32*, i32 } }, { { i32*, i32 }, { i32*, i32 } }* %x, i32 0, i32 0
  %field.1 = getelementptr inbounds { i32*, i32 }, { i32*, i32 }* %field.0, i32 0, i32 0
  %x.field.field.ld.0 = load i32*, i32** %field.1
  %.ld.0 = load i32, i32* %x.field.field.ld.0
  %field.2 = getelementptr inbounds { { i32*, i32 }, { i32*, i32 } }, { { i32*, i32 }, { i32*, i32 } }* %x, i32 0, i32 0
  %field.3 = getelementptr inbounds { i32*, i32 }, { i32*, i32 }* %field.2, i32 0, i32 0
  %.field.field.ld.0 = load i32*, i32** %field.3
  %.ld.1 = load i32, i32* %.field.field.ld.0
  %add.0 = add i32 %.ld.0, %.ld.1
    )RAW_RESULT";

  bool isOK = h.expectRepr(matadd, exp2);
  EXPECT_TRUE(isOK && "expr does not have expected contents");

  h.mkExprStmt(matadd);

  bool broken = h.finish(PreserveDebugInfo);
  EXPECT_FALSE(broken && "Module failed to verify.");
}

}