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#include "cps/CodeGen.h"
#include "cps/ArrayHandler.h"
#include "cps/ExceptionHandler.h"
using namespace llvm;
using namespace cps;
void CodeGen::emitTryStmt(TryStmtAST *Stmt) {
auto *F = Builder->GetInsertBlock()->getParent();
auto *CatchBB = BasicBlock::Create(*TheContext, "catch", F);
auto *AfterBB = BasicBlock::Create(*TheContext, "try_cont", F);
auto SavedArrays = Arrays->snapshotTable();
Exceptions->pushHandler(CatchBB);
for (const auto &S : Stmt->getBody()) emitStmt(S.get());
auto *Exception = Exceptions->popHandler();
if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
Arrays->exchangeTable(SavedArrays);
Builder->SetInsertPoint(CatchBB);
Exceptions->beginCatch(Exception);
for (const auto &S : Stmt->getCatchBody()) emitStmt(S.get());
Exceptions->endCatch();
if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
Arrays->exchangeTable(std::move(SavedArrays));
Builder->SetInsertPoint(AfterBB);
}
void CodeGen::emitIfStmt(IfStmtAST *Stmt) {
Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
if (!CondV) return;
Function *TheFunction = Builder->GetInsertBlock()->getParent();
BasicBlock *ThenBB = BasicBlock::Create(*TheContext, "then", TheFunction);
BasicBlock *ElseBB = BasicBlock::Create(*TheContext, "else", TheFunction);
BasicBlock *MergeBB = BasicBlock::Create(*TheContext, "ifcont", TheFunction);
Builder->CreateCondBr(CondV, ThenBB, ElseBB);
// Arrays are block-scoped: metadata SSA values and the buffer setup live
// inside the branch, so a declaration must not survive it.
auto SavedArrays = Arrays->snapshotTable();
Builder->SetInsertPoint(ThenBB);
for (const auto &S : Stmt->getThenStmts()) emitStmt(S.get());
if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
Arrays->exchangeTable(SavedArrays);
Builder->SetInsertPoint(ElseBB);
for (const auto &S : Stmt->getElseStmts()) emitStmt(S.get());
if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
Arrays->exchangeTable(std::move(SavedArrays));
Builder->SetInsertPoint(MergeBB);
}
void CodeGen::emitWhileStmt(WhileStmtAST *Stmt) {
Function *TheFunction = Builder->GetInsertBlock()->getParent();
BasicBlock *CondBB = BasicBlock::Create(*TheContext, "whilecond", TheFunction);
BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "whileloop", TheFunction);
BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "whilecont", TheFunction);
Builder->CreateBr(CondBB);
Builder->SetInsertPoint(CondBB);
Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
if (!CondV) return;
Builder->CreateCondBr(CondV, LoopBB, AfterBB);
// Arrays declared in the body are block-scoped (see emitIfStmt).
auto SavedArrays = Arrays->snapshotTable();
Builder->SetInsertPoint(LoopBB);
for (const auto &S : Stmt->getBody()) emitStmt(S.get());
Arrays->exchangeTable(std::move(SavedArrays));
if (!Builder->GetInsertBlock()->hasTerminator())
Builder->CreateBr(CondBB);
Builder->SetInsertPoint(AfterBB);
}
void CodeGen::emitRepeatStmt(RepeatStmtAST *Stmt) {
Function *TheFunction = Builder->GetInsertBlock()->getParent();
BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "repeatloop", TheFunction);
BasicBlock *CondBB = BasicBlock::Create(*TheContext, "repeatcond", TheFunction);
BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "repeatcont", TheFunction);
Builder->CreateBr(LoopBB);
// Arrays declared in the body are block-scoped (see emitIfStmt).
auto SavedArrays = Arrays->snapshotTable();
Builder->SetInsertPoint(LoopBB);
for (const auto &S : Stmt->getBody()) emitStmt(S.get());
Arrays->exchangeTable(std::move(SavedArrays));
if (!Builder->GetInsertBlock()->hasTerminator())
Builder->CreateBr(CondBB);
Builder->SetInsertPoint(CondBB);
Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
if (!CondV) return;
Builder->CreateCondBr(CondV, AfterBB, LoopBB);
Builder->SetInsertPoint(AfterBB);
}
void CodeGen::emitForStmt(ForStmtAST *Stmt) {
Function *TheFunction = Builder->GetInsertBlock()->getParent();
std::string VarName = Stmt->getVarName();
const SymbolInfo *Symbol = getSymbolInfo(VarName);
if (!Symbol) {
reportError("Unknown variable in FOR loop %s", VarName.c_str());
return;
}
if (Symbol->TypeName != "INTEGER") {
reportError("FOR loop variable %s must be INTEGER", VarName.c_str());
return;
}
Value *StartVal = emitCoercedExpr(Stmt->getStart(), resolveType("INTEGER"));
if (!StartVal) return;
Value *Alloca = Symbol->Storage;
Builder->CreateStore(StartVal, Alloca);
// STEP is evaluated exactly once, before the loop.
Value *StepVal = nullptr;
if (Stmt->getStep()) {
StepVal = emitCoercedExpr(Stmt->getStep(), resolveType("INTEGER"));
if (!StepVal) return;
} else {
StepVal = ConstantInt::get(*TheContext, APInt(64, 1));
}
BasicBlock *CondBB = BasicBlock::Create(*TheContext, "forcond", TheFunction);
BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "forloop", TheFunction);
BasicBlock *IncBB = BasicBlock::Create(*TheContext, "forinc", TheFunction);
BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "forcont", TheFunction);
Builder->CreateBr(CondBB);
Builder->SetInsertPoint(CondBB);
Value *CurVar = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
Value *EndVal = emitCoercedExpr(Stmt->getEnd(), resolveType("INTEGER"));
if (!EndVal) return;
// The loop direction depends on the STEP value at run time.
Value *StepNonNeg = Builder->CreateICmpSGE(StepVal,
ConstantInt::get(*TheContext, APInt(64, 0)),
"step_nonneg");
Value *CondUp = Builder->CreateICmpSLE(CurVar, EndVal, "forcond_le");
Value *CondDown = Builder->CreateICmpSGE(CurVar, EndVal, "forcond_ge");
Value *CondV = Builder->CreateSelect(StepNonNeg, CondUp, CondDown, "forcond");
Builder->CreateCondBr(CondV, LoopBB, AfterBB);
// Arrays declared in the body are block-scoped (see emitIfStmt).
auto SavedArrays = Arrays->snapshotTable();
Builder->SetInsertPoint(LoopBB);
for (const auto &S : Stmt->getBody()) emitStmt(S.get());
Arrays->exchangeTable(std::move(SavedArrays));
if (!Builder->GetInsertBlock()->hasTerminator())
Builder->CreateBr(IncBB);
Builder->SetInsertPoint(IncBB);
Value *CurValForInc = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
Value *NextVal = Builder->CreateAdd(CurValForInc, StepVal, "nextval");
Builder->CreateStore(NextVal, Alloca);
Builder->CreateBr(CondBB);
Builder->SetInsertPoint(AfterBB);
}
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