use sqlite3_parser::ast::{self, UnaryOperator}; #[cfg(feature = "json")] use crate::function::JsonFunc; use crate::function::{Func, FuncCtx, MathFuncArity, ScalarFunc}; use crate::schema::Type; use crate::util::normalize_ident; use crate::vdbe::{builder::ProgramBuilder, insn::Insn, BranchOffset}; use crate::Result; use super::emitter::Resolver; use super::plan::{TableReference, TableReferenceType}; #[derive(Debug, Clone, Copy)] pub struct ConditionMetadata { pub jump_if_condition_is_true: bool, pub jump_target_when_true: BranchOffset, pub jump_target_when_false: BranchOffset, } fn emit_cond_jump(program: &mut ProgramBuilder, cond_meta: ConditionMetadata, reg: usize) { if cond_meta.jump_if_condition_is_true { program.emit_insn(Insn::If { reg, target_pc: cond_meta.jump_target_when_true, null_reg: reg, }); } else { program.emit_insn(Insn::IfNot { reg, target_pc: cond_meta.jump_target_when_false, null_reg: reg, }); } } macro_rules! emit_cmp_insn { ( $program:expr, $cond:expr, $op_true:ident, $op_false:ident, $lhs:expr, $rhs:expr ) => {{ if $cond.jump_if_condition_is_true { $program.emit_insn(Insn::$op_true { lhs: $lhs, rhs: $rhs, target_pc: $cond.jump_target_when_true, }); } else { $program.emit_insn(Insn::$op_false { lhs: $lhs, rhs: $rhs, target_pc: $cond.jump_target_when_false, }); } }}; } macro_rules! expect_arguments_exact { ( $args:expr, $expected_arguments:expr, $func:ident ) => {{ let args = if let Some(args) = $args { if args.len() != $expected_arguments { crate::bail_parse_error!( "{} function called with not exactly {} arguments", $func.to_string(), $expected_arguments, ); } args } else { crate::bail_parse_error!("{} function with no arguments", $func.to_string()); }; args }}; } macro_rules! expect_arguments_max { ( $args:expr, $expected_arguments:expr, $func:ident ) => {{ let args = if let Some(args) = $args { if args.len() > $expected_arguments { crate::bail_parse_error!( "{} function called with more than {} arguments", $func.to_string(), $expected_arguments, ); } args } else { crate::bail_parse_error!("{} function with no arguments", $func.to_string()); }; args }}; } macro_rules! expect_arguments_min { ( $args:expr, $expected_arguments:expr, $func:ident ) => {{ let args = if let Some(args) = $args { if args.len() < $expected_arguments { crate::bail_parse_error!( "{} function with less than {} arguments", $func.to_string(), $expected_arguments ); } args } else { crate::bail_parse_error!("{} function with no arguments", $func.to_string()); }; args }}; } pub fn translate_condition_expr( program: &mut ProgramBuilder, referenced_tables: &[TableReference], expr: &ast::Expr, condition_metadata: ConditionMetadata, resolver: &Resolver, ) -> Result<()> { match expr { ast::Expr::Between { .. } => todo!(), ast::Expr::Binary(lhs, ast::Operator::And, rhs) => { // In a binary AND, never jump to the parent 'jump_target_when_true' label on the first condition, because // the second condition MUST also be true. Instead we instruct the child expression to jump to a local // true label. let jump_target_when_true = program.allocate_label(); translate_condition_expr( program, referenced_tables, lhs, ConditionMetadata { jump_target_when_true, ..condition_metadata }, resolver, )?; program.resolve_label(jump_target_when_true, program.offset()); translate_condition_expr( program, referenced_tables, rhs, condition_metadata, resolver, )?; } ast::Expr::Binary(lhs, ast::Operator::Or, rhs) => { // In a binary OR, never jump to the parent 'jump_target_when_false' label on the first condition, because // the second condition CAN also be true. Instead we instruct the child expression to jump to a local // false label. let jump_target_when_false = program.allocate_label(); translate_condition_expr( program, referenced_tables, lhs, ConditionMetadata { jump_if_condition_is_true: true, jump_target_when_false, ..condition_metadata }, resolver, )?; program.resolve_label(jump_target_when_false, program.offset()); translate_condition_expr( program, referenced_tables, rhs, condition_metadata, resolver, )?; } ast::Expr::Binary(lhs, op, rhs) => { let lhs_reg = translate_and_mark(program, Some(referenced_tables), lhs, resolver)?; let rhs_reg = translate_and_mark(program, Some(referenced_tables), rhs, resolver)?; match op { ast::Operator::Greater => { emit_cmp_insn!(program, condition_metadata, Gt, Le, lhs_reg, rhs_reg) } ast::Operator::GreaterEquals => { emit_cmp_insn!(program, condition_metadata, Ge, Lt, lhs_reg, rhs_reg) } ast::Operator::Less => { emit_cmp_insn!(program, condition_metadata, Lt, Ge, lhs_reg, rhs_reg) } ast::Operator::LessEquals => { emit_cmp_insn!(program, condition_metadata, Le, Gt, lhs_reg, rhs_reg) } ast::Operator::Equals => { emit_cmp_insn!(program, condition_metadata, Eq, Ne, lhs_reg, rhs_reg) } ast::Operator::NotEquals => { emit_cmp_insn!(program, condition_metadata, Ne, Eq, lhs_reg, rhs_reg) } ast::Operator::Is => todo!(), ast::Operator::IsNot => todo!(), _ => { todo!("op {:?} not implemented", op); } } } ast::Expr::Literal(lit) => match lit { ast::Literal::Numeric(val) => { let maybe_int = val.parse::(); if let Ok(int_value) = maybe_int { let reg = program.alloc_register(); program.emit_insn(Insn::Integer { value: int_value, dest: reg, }); emit_cond_jump(program, condition_metadata, reg); } else { crate::bail_parse_error!("unsupported literal type in condition"); } } ast::Literal::String(string) => { let reg = program.alloc_register(); program.emit_insn(Insn::String8 { value: string.clone(), dest: reg, }); emit_cond_jump(program, condition_metadata, reg); } unimpl => todo!("literal {:?} not implemented", unimpl), }, ast::Expr::InList { lhs, not, rhs } => { // lhs is e.g. a column reference // rhs is an Option> // If rhs is None, it means the IN expression is always false, i.e. tbl.id IN (). // If rhs is Some, it means the IN expression has a list of values to compare against, e.g. tbl.id IN (1, 2, 3). // // The IN expression is equivalent to a series of OR expressions. // For example, `a IN (1, 2, 3)` is equivalent to `a = 1 OR a = 2 OR a = 3`. // The NOT IN expression is equivalent to a series of AND expressions. // For example, `a NOT IN (1, 2, 3)` is equivalent to `a != 1 AND a != 2 AND a != 3`. // // SQLite typically optimizes IN expressions to use a binary search on an ephemeral index if there are many values. // For now we don't have the plumbing to do that, so we'll just emit a series of comparisons, // which is what SQLite also does for small lists of values. // TODO: Let's refactor this later to use a more efficient implementation conditionally based on the number of values. if rhs.is_none() { // If rhs is None, IN expressions are always false and NOT IN expressions are always true. if *not { // On a trivially true NOT IN () expression we can only jump to the 'jump_target_when_true' label if 'jump_if_condition_is_true'; otherwise me must fall through. // This is because in a more complex condition we might need to evaluate the rest of the condition. // Note that we are already breaking up our WHERE clauses into a series of terms at "AND" boundaries, so right now we won't be running into cases where jumping on true would be incorrect, // but once we have e.g. parenthesization and more complex conditions, not having this 'if' here would introduce a bug. if condition_metadata.jump_if_condition_is_true { program.emit_insn(Insn::Goto { target_pc: condition_metadata.jump_target_when_true, }); } } else { program.emit_insn(Insn::Goto { target_pc: condition_metadata.jump_target_when_false, }); } return Ok(()); } // The left hand side only needs to be evaluated once we have a list of values to compare against. let lhs_reg = program.alloc_register(); let _ = translate_expr(program, Some(referenced_tables), lhs, lhs_reg, resolver)?; let rhs = rhs.as_ref().unwrap(); // The difference between a local jump and an "upper level" jump is that for example in this case: // WHERE foo IN (1,2,3) OR bar = 5, // we can immediately jump to the 'jump_target_when_true' label of the ENTIRE CONDITION if foo = 1, foo = 2, or foo = 3 without evaluating the bar = 5 condition. // This is why in Binary-OR expressions we set jump_if_condition_is_true to true for the first condition. // However, in this example: // WHERE foo IN (1,2,3) AND bar = 5, // we can't jump to the 'jump_target_when_true' label of the entire condition foo = 1, foo = 2, or foo = 3, because we still need to evaluate the bar = 5 condition later. // This is why in that case we just jump over the rest of the IN conditions in this "local" branch which evaluates the IN condition. let jump_target_when_true = if condition_metadata.jump_if_condition_is_true { condition_metadata.jump_target_when_true } else { program.allocate_label() }; if !*not { // If it's an IN expression, we need to jump to the 'jump_target_when_true' label if any of the conditions are true. for (i, expr) in rhs.iter().enumerate() { let rhs_reg = program.alloc_register(); let last_condition = i == rhs.len() - 1; let _ = translate_expr(program, Some(referenced_tables), expr, rhs_reg, resolver)?; // If this is not the last condition, we need to jump to the 'jump_target_when_true' label if the condition is true. if !last_condition { program.emit_insn(Insn::Eq { lhs: lhs_reg, rhs: rhs_reg, target_pc: jump_target_when_true, }); } else { // If this is the last condition, we need to jump to the 'jump_target_when_false' label if there is no match. program.emit_insn(Insn::Ne { lhs: lhs_reg, rhs: rhs_reg, target_pc: condition_metadata.jump_target_when_false, }); } } // If we got here, then the last condition was a match, so we jump to the 'jump_target_when_true' label if 'jump_if_condition_is_true'. // If not, we can just fall through without emitting an unnecessary instruction. if condition_metadata.jump_if_condition_is_true { program.emit_insn(Insn::Goto { target_pc: condition_metadata.jump_target_when_true, }); } } else { // If it's a NOT IN expression, we need to jump to the 'jump_target_when_false' label if any of the conditions are true. for expr in rhs.iter() { let rhs_reg = program.alloc_register(); let _ = translate_expr(program, Some(referenced_tables), expr, rhs_reg, resolver)?; program.emit_insn(Insn::Eq { lhs: lhs_reg, rhs: rhs_reg, target_pc: condition_metadata.jump_target_when_false, }); } // If we got here, then none of the conditions were a match, so we jump to the 'jump_target_when_true' label if 'jump_if_condition_is_true'. // If not, we can just fall through without emitting an unnecessary instruction. if condition_metadata.jump_if_condition_is_true { program.emit_insn(Insn::Goto { target_pc: condition_metadata.jump_target_when_true, }); } } if !condition_metadata.jump_if_condition_is_true { program.resolve_label(jump_target_when_true, program.offset()); } } ast::Expr::Like { lhs, not, op, rhs, escape: _, } => { let cur_reg = program.alloc_register(); match op { ast::LikeOperator::Like | ast::LikeOperator::Glob => { let pattern_reg = program.alloc_register(); let mut constant_mask = 0; let _ = translate_and_mark(program, Some(referenced_tables), lhs, resolver); let _ = translate_expr( program, Some(referenced_tables), rhs, pattern_reg, resolver, )?; if matches!(rhs.as_ref(), ast::Expr::Literal(_)) { program.mark_last_insn_constant(); constant_mask = 1; } let func = match op { ast::LikeOperator::Like => ScalarFunc::Like, ast::LikeOperator::Glob => ScalarFunc::Glob, _ => unreachable!(), }; program.emit_insn(Insn::Function { constant_mask, start_reg: pattern_reg, dest: cur_reg, func: FuncCtx { func: Func::Scalar(func), arg_count: 2, }, }); } ast::LikeOperator::Match => todo!(), ast::LikeOperator::Regexp => todo!(), } if !*not { emit_cond_jump(program, condition_metadata, cur_reg); } else if condition_metadata.jump_if_condition_is_true { program.emit_insn(Insn::IfNot { reg: cur_reg, target_pc: condition_metadata.jump_target_when_true, null_reg: cur_reg, }); } else { program.emit_insn(Insn::If { reg: cur_reg, target_pc: condition_metadata.jump_target_when_false, null_reg: cur_reg, }); } } ast::Expr::Parenthesized(exprs) => { if exprs.len() == 1 { let _ = translate_condition_expr( program, referenced_tables, &exprs[0], condition_metadata, resolver, ); } else { crate::bail_parse_error!( "parenthesized condtional should have exactly one expression" ); } } _ => todo!("op {:?} not implemented", expr), } Ok(()) } pub fn translate_expr( program: &mut ProgramBuilder, referenced_tables: Option<&[TableReference]>, expr: &ast::Expr, target_register: usize, resolver: &Resolver, ) -> Result { if let Some(reg) = resolver.resolve_cached_expr_reg(expr) { program.emit_insn(Insn::Copy { src_reg: reg, dst_reg: target_register, amount: 0, }); return Ok(target_register); } match expr { ast::Expr::Between { .. } => todo!(), ast::Expr::Binary(e1, op, e2) => { let e1_reg = program.alloc_registers(2); let e2_reg = e1_reg + 1; translate_expr(program, referenced_tables, e1, e1_reg, resolver)?; translate_expr(program, referenced_tables, e2, e2_reg, resolver)?; match op { ast::Operator::NotEquals => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Ne { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::Equals => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Eq { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::Less => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Lt { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::LessEquals => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Le { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::Greater => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Gt { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::GreaterEquals => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr_zero_or_null( program, Insn::Ge { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, e1_reg, e2_reg, ); } ast::Operator::Add => { program.emit_insn(Insn::Add { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::Subtract => { program.emit_insn(Insn::Subtract { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::Multiply => { program.emit_insn(Insn::Multiply { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::Divide => { program.emit_insn(Insn::Divide { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::Modulus => { program.emit_insn(Insn::Remainder { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::BitwiseAnd => { program.emit_insn(Insn::BitAnd { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::BitwiseOr => { program.emit_insn(Insn::BitOr { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::RightShift => { program.emit_insn(Insn::ShiftRight { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::LeftShift => { program.emit_insn(Insn::ShiftLeft { lhs: e1_reg, rhs: e2_reg, dest: target_register, }); } ast::Operator::Is => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr( program, Insn::Eq { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, ); } ast::Operator::IsNot => { let if_true_label = program.allocate_label(); wrap_eval_jump_expr( program, Insn::Ne { lhs: e1_reg, rhs: e2_reg, target_pc: if_true_label, }, target_register, if_true_label, ); } #[cfg(feature = "json")] op @ (ast::Operator::ArrowRight | ast::Operator::ArrowRightShift) => { let json_func = match op { ast::Operator::ArrowRight => JsonFunc::JsonArrowExtract, ast::Operator::ArrowRightShift => JsonFunc::JsonArrowShiftExtract, _ => unreachable!(), }; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: e1_reg, dest: target_register, func: FuncCtx { func: Func::Json(json_func), arg_count: 2, }, }) } other_unimplemented => todo!("{:?}", other_unimplemented), } Ok(target_register) } ast::Expr::Case { base, when_then_pairs, else_expr, } => { // There's two forms of CASE, one which checks a base expression for equality // against the WHEN values, and returns the corresponding THEN value if it matches: // CASE 2 WHEN 1 THEN 'one' WHEN 2 THEN 'two' ELSE 'many' END // And one which evaluates a series of boolean predicates: // CASE WHEN is_good THEN 'good' WHEN is_bad THEN 'bad' ELSE 'okay' END // This just changes which sort of branching instruction to issue, after we // generate the expression if needed. let return_label = program.allocate_label(); let mut next_case_label = program.allocate_label(); // Only allocate a reg to hold the base expression if one was provided. // And base_reg then becomes the flag we check to see which sort of // case statement we're processing. let base_reg = base.as_ref().map(|_| program.alloc_register()); let expr_reg = program.alloc_register(); if let Some(base_expr) = base { translate_expr( program, referenced_tables, base_expr, base_reg.unwrap(), resolver, )?; }; for (when_expr, then_expr) in when_then_pairs { translate_expr(program, referenced_tables, when_expr, expr_reg, resolver)?; match base_reg { // CASE 1 WHEN 0 THEN 0 ELSE 1 becomes 1==0, Ne branch to next clause Some(base_reg) => program.emit_insn(Insn::Ne { lhs: base_reg, rhs: expr_reg, target_pc: next_case_label, }), // CASE WHEN 0 THEN 0 ELSE 1 becomes ifnot 0 branch to next clause None => program.emit_insn(Insn::IfNot { reg: expr_reg, target_pc: next_case_label, null_reg: 1, }), }; // THEN... translate_expr( program, referenced_tables, then_expr, target_register, resolver, )?; program.emit_insn(Insn::Goto { target_pc: return_label, }); // This becomes either the next WHEN, or in the last WHEN/THEN, we're // assured to have at least one instruction corresponding to the ELSE immediately follow. program.preassign_label_to_next_insn(next_case_label); next_case_label = program.allocate_label(); } match else_expr { Some(expr) => { translate_expr(program, referenced_tables, expr, target_register, resolver)?; } // If ELSE isn't specified, it means ELSE null. None => { program.emit_insn(Insn::Null { dest: target_register, dest_end: None, }); } }; program.resolve_label(return_label, program.offset()); Ok(target_register) } ast::Expr::Cast { expr, type_name } => { let type_name = type_name.as_ref().unwrap(); // TODO: why is this optional? let reg_expr = program.alloc_register(); translate_expr(program, referenced_tables, expr, reg_expr, resolver)?; let reg_type = program.alloc_register(); program.emit_insn(Insn::String8 { // we make a comparison against uppercase static strs in the affinity() function, // so we need to make sure we're comparing against the uppercase version, // and it's better to do this once instead of every time we check affinity value: type_name.name.to_uppercase(), dest: reg_type, }); program.mark_last_insn_constant(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg: reg_expr, dest: target_register, func: FuncCtx { func: Func::Scalar(ScalarFunc::Cast), arg_count: 2, }, }); Ok(target_register) } ast::Expr::Collate(_, _) => todo!(), ast::Expr::DoublyQualified(_, _, _) => todo!(), ast::Expr::Exists(_) => todo!(), ast::Expr::FunctionCall { name, distinctness: _, args, filter_over: _, order_by: _, } => { let args_count = if let Some(args) = args { args.len() } else { 0 }; let func_name = normalize_ident(name.0.as_str()); let func_type = resolver.resolve_function(&func_name, args_count); if func_type.is_none() { crate::bail_parse_error!("unknown function {}", name.0); } let func_ctx = FuncCtx { func: func_type.unwrap(), arg_count: args_count, }; match &func_ctx.func { Func::Agg(_) => { crate::bail_parse_error!("aggregation function in non-aggregation context") } Func::External(_) => { let regs = program.alloc_registers(args_count); if let Some(args) = args { for (i, arg_expr) in args.iter().enumerate() { translate_expr( program, referenced_tables, &arg_expr, regs + i, resolver, )?; } } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: regs, dest: target_register, func: func_ctx, }); Ok(target_register) } #[cfg(feature = "json")] Func::Json(j) => match j { JsonFunc::Json => { let args = expect_arguments_exact!(args, 1, j); translate_function( program, args, referenced_tables, resolver, target_register, func_ctx, ) } JsonFunc::JsonArray | JsonFunc::JsonExtract => translate_function( program, args.as_deref().unwrap_or_default(), referenced_tables, resolver, target_register, func_ctx, ), JsonFunc::JsonArrowExtract | JsonFunc::JsonArrowShiftExtract => { unreachable!( "These two functions are only reachable via the -> and ->> operators" ) } JsonFunc::JsonArrayLength | JsonFunc::JsonType => { let args = expect_arguments_max!(args, 2, j); translate_function( program, args, referenced_tables, resolver, target_register, func_ctx, ) } JsonFunc::JsonErrorPosition => { let args = if let Some(args) = args { if args.len() != 1 { crate::bail_parse_error!( "{} function with not exactly 1 argument", j.to_string() ); } args } else { crate::bail_parse_error!( "{} function with no arguments", j.to_string() ); }; let json_reg = program.alloc_register(); translate_expr(program, referenced_tables, &args[0], json_reg, resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: json_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } }, Func::Scalar(srf) => { match srf { ScalarFunc::Cast => { unreachable!("this is always ast::Expr::Cast") } ScalarFunc::Changes => { if args.is_some() { crate::bail_parse_error!( "{} function with more than 0 arguments", srf ); } let start_reg = program.alloc_register(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Char => translate_function( program, args.as_deref().unwrap_or_default(), referenced_tables, resolver, target_register, func_ctx, ), ScalarFunc::Coalesce => { let args = expect_arguments_min!(args, 2, srf); // coalesce function is implemented as a series of not null checks // whenever a not null check succeeds, we jump to the end of the series let label_coalesce_end = program.allocate_label(); for (index, arg) in args.iter().enumerate() { let reg = translate_expr( program, referenced_tables, arg, target_register, resolver, )?; if index < args.len() - 1 { program.emit_insn(Insn::NotNull { reg, target_pc: label_coalesce_end, }); } } program.preassign_label_to_next_insn(label_coalesce_end); Ok(target_register) } ScalarFunc::LastInsertRowid => { let regs = program.alloc_register(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg: regs, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Concat => { let args = if let Some(args) = args { args } else { crate::bail_parse_error!( "{} function with no arguments", srf.to_string() ); }; let mut start_reg = None; for arg in args.iter() { let reg = program.alloc_register(); start_reg = Some(start_reg.unwrap_or(reg)); translate_expr(program, referenced_tables, arg, reg, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: start_reg.unwrap(), dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::ConcatWs => { let args = expect_arguments_min!(args, 2, srf); let temp_register = program.alloc_register(); for arg in args.iter() { let reg = program.alloc_register(); translate_expr(program, referenced_tables, arg, reg, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: temp_register + 1, dest: temp_register, func: func_ctx, }); program.emit_insn(Insn::Copy { src_reg: temp_register, dst_reg: target_register, amount: 1, }); Ok(target_register) } ScalarFunc::IfNull => { let args = match args { Some(args) if args.len() == 2 => args, Some(_) => crate::bail_parse_error!( "{} function requires exactly 2 arguments", srf.to_string() ), None => crate::bail_parse_error!( "{} function requires arguments", srf.to_string() ), }; let temp_reg = program.alloc_register(); translate_expr( program, referenced_tables, &args[0], temp_reg, resolver, )?; program.emit_insn(Insn::NotNull { reg: temp_reg, target_pc: program.offset().add(2u32), }); translate_expr( program, referenced_tables, &args[1], temp_reg, resolver, )?; program.emit_insn(Insn::Copy { src_reg: temp_reg, dst_reg: target_register, amount: 0, }); Ok(target_register) } ScalarFunc::Iif => { let args = match args { Some(args) if args.len() == 3 => args, _ => crate::bail_parse_error!( "{} requires exactly 3 arguments", srf.to_string() ), }; let temp_reg = program.alloc_register(); translate_expr( program, referenced_tables, &args[0], temp_reg, resolver, )?; let jump_target_when_false = program.allocate_label(); program.emit_insn(Insn::IfNot { reg: temp_reg, target_pc: jump_target_when_false, null_reg: 1, }); translate_expr( program, referenced_tables, &args[1], target_register, resolver, )?; let jump_target_result = program.allocate_label(); program.emit_insn(Insn::Goto { target_pc: jump_target_result, }); program.resolve_label(jump_target_when_false, program.offset()); translate_expr( program, referenced_tables, &args[2], target_register, resolver, )?; program.resolve_label(jump_target_result, program.offset()); Ok(target_register) } ScalarFunc::Glob | ScalarFunc::Like => { let args = if let Some(args) = args { if args.len() < 2 { crate::bail_parse_error!( "{} function with less than 2 arguments", srf.to_string() ); } args } else { crate::bail_parse_error!( "{} function with no arguments", srf.to_string() ); }; for arg in args { let _ = translate_and_mark(program, referenced_tables, arg, resolver); } program.emit_insn(Insn::Function { // Only constant patterns for LIKE are supported currently, so this // is always 1 constant_mask: 1, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Abs | ScalarFunc::Lower | ScalarFunc::Upper | ScalarFunc::Length | ScalarFunc::OctetLength | ScalarFunc::Typeof | ScalarFunc::Unicode | ScalarFunc::Quote | ScalarFunc::RandomBlob | ScalarFunc::Sign | ScalarFunc::Soundex | ScalarFunc::ZeroBlob => { let args = expect_arguments_exact!(args, 1, srf); let reg = translate_and_mark(program, referenced_tables, &args[0], resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: reg, dest: target_register, func: func_ctx, }); Ok(target_register) } #[cfg(not(target_family = "wasm"))] ScalarFunc::LoadExtension => { let args = expect_arguments_exact!(args, 1, srf); let reg = translate_and_mark(program, referenced_tables, &args[0], resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Random => { if args.is_some() { crate::bail_parse_error!( "{} function with arguments", srf.to_string() ); } let regs = program.alloc_register(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg: regs, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Date | ScalarFunc::DateTime => { if let Some(args) = args { for arg in args.iter() { // register containing result of each argument expression let _ = translate_and_mark( program, referenced_tables, arg, resolver, )?; } } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Substr | ScalarFunc::Substring => { let args = if let Some(args) = args { if !(args.len() == 2 || args.len() == 3) { crate::bail_parse_error!( "{} function with wrong number of arguments", srf.to_string() ) } args } else { crate::bail_parse_error!( "{} function with no arguments", srf.to_string() ); }; let str_reg = program.alloc_register(); let start_reg = program.alloc_register(); let length_reg = program.alloc_register(); let str_reg = translate_expr( program, referenced_tables, &args[0], str_reg, resolver, )?; let _ = translate_expr( program, referenced_tables, &args[1], start_reg, resolver, )?; if args.len() == 3 { translate_expr( program, referenced_tables, &args[2], length_reg, resolver, )?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: str_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Hex => { let args = if let Some(args) = args { if args.len() != 1 { crate::bail_parse_error!( "hex function must have exactly 1 argument", ); } args } else { crate::bail_parse_error!("hex function with no arguments",); }; let regs = translate_and_mark(program, referenced_tables, &args[0], resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: regs, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::UnixEpoch | ScalarFunc::JulianDay => { let mut start_reg = 0; match args { Some(args) if args.len() > 1 => { crate::bail_parse_error!("epoch or julianday function with > 1 arguments. Modifiers are not yet supported."); } Some(args) if args.len() == 1 => { let arg_reg = program.alloc_register(); let _ = translate_expr( program, referenced_tables, &args[0], arg_reg, resolver, )?; start_reg = arg_reg; } _ => {} } program.emit_insn(Insn::Function { constant_mask: 0, start_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Time => { if let Some(args) = args { for arg in args.iter() { // register containing result of each argument expression let _ = translate_and_mark( program, referenced_tables, arg, resolver, )?; } } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::TotalChanges => { if args.is_some() { crate::bail_parse_error!( "{} fucntion with more than 0 arguments", srf.to_string() ); } let start_reg = program.alloc_register(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Trim | ScalarFunc::LTrim | ScalarFunc::RTrim | ScalarFunc::Round | ScalarFunc::Unhex => { let args = expect_arguments_max!(args, 2, srf); for arg in args.iter() { translate_and_mark(program, referenced_tables, arg, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Min => { let args = if let Some(args) = args { if args.is_empty() { crate::bail_parse_error!( "min function with less than one argument" ); } args } else { crate::bail_parse_error!("min function with no arguments"); }; for arg in args { translate_and_mark(program, referenced_tables, arg, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Max => { let args = if let Some(args) = args { if args.is_empty() { crate::bail_parse_error!( "max function with less than one argument" ); } args } else { crate::bail_parse_error!("max function with no arguments"); }; for arg in args { translate_and_mark(program, referenced_tables, arg, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::Nullif | ScalarFunc::Instr => { let args = if let Some(args) = args { if args.len() != 2 { crate::bail_parse_error!( "{} function must have two argument", srf.to_string() ); } args } else { crate::bail_parse_error!( "{} function with no arguments", srf.to_string() ); }; let first_reg = program.alloc_register(); translate_expr( program, referenced_tables, &args[0], first_reg, resolver, )?; let second_reg = program.alloc_register(); let _ = translate_expr( program, referenced_tables, &args[1], second_reg, resolver, )?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: first_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } ScalarFunc::SqliteVersion => { if args.is_some() { crate::bail_parse_error!("sqlite_version function with arguments"); } let output_register = program.alloc_register(); program.emit_insn(Insn::Function { constant_mask: 0, start_reg: output_register, dest: output_register, func: func_ctx, }); program.emit_insn(Insn::Copy { src_reg: output_register, dst_reg: target_register, amount: 0, }); Ok(target_register) } ScalarFunc::Replace => { let args = if let Some(args) = args { if !args.len() == 3 { crate::bail_parse_error!( "function {}() requires exactly 3 arguments", srf.to_string() ) } args } else { crate::bail_parse_error!( "function {}() requires exactly 3 arguments", srf.to_string() ); }; let str_reg = program.alloc_register(); let pattern_reg = program.alloc_register(); let replacement_reg = program.alloc_register(); let _ = translate_expr( program, referenced_tables, &args[0], str_reg, resolver, )?; let _ = translate_expr( program, referenced_tables, &args[1], pattern_reg, resolver, )?; let _ = translate_expr( program, referenced_tables, &args[2], replacement_reg, resolver, )?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: str_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } } } Func::Math(math_func) => match math_func.arity() { MathFuncArity::Nullary => { if args.is_some() { crate::bail_parse_error!("{} function with arguments", math_func); } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: 0, dest: target_register, func: func_ctx, }); Ok(target_register) } MathFuncArity::Unary => { let args = expect_arguments_exact!(args, 1, math_func); let reg = translate_and_mark(program, referenced_tables, &args[0], resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: reg, dest: target_register, func: func_ctx, }); Ok(target_register) } MathFuncArity::Binary => { let args = expect_arguments_exact!(args, 2, math_func); let reg1 = program.alloc_register(); let _ = translate_expr(program, referenced_tables, &args[0], reg1, resolver)?; let reg2 = program.alloc_register(); let _ = translate_expr(program, referenced_tables, &args[1], reg2, resolver)?; program.emit_insn(Insn::Function { constant_mask: 0, start_reg: target_register + 1, dest: target_register, func: func_ctx, }); Ok(target_register) } MathFuncArity::UnaryOrBinary => { let args = expect_arguments_max!(args, 2, math_func); let regs = program.alloc_registers(args.len()); for (i, arg) in args.iter().enumerate() { translate_expr(program, referenced_tables, arg, regs + i, resolver)?; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg: regs, dest: target_register, func: func_ctx, }); Ok(target_register) } }, } } ast::Expr::FunctionCallStar { .. } => todo!(), ast::Expr::Id(_) => unreachable!("Id should be resolved to a Column before translation"), ast::Expr::Column { database: _, table, column, is_rowid_alias, } => { let tbl_ref = referenced_tables.as_ref().unwrap().get(*table).unwrap(); match tbl_ref.reference_type { // If we are reading a column from a table, we find the cursor that corresponds to // the table and read the column from the cursor. TableReferenceType::BTreeTable => { let cursor_id = program.resolve_cursor_id(&tbl_ref.table_identifier); if *is_rowid_alias { program.emit_insn(Insn::RowId { cursor_id, dest: target_register, }); } else { program.emit_insn(Insn::Column { cursor_id, column: *column, dest: target_register, }); } let column = tbl_ref.table.get_column_at(*column); maybe_apply_affinity(column.ty, target_register, program); Ok(target_register) } // If we are reading a column from a subquery, we instead copy the column from the // subquery's result registers. TableReferenceType::Subquery { result_columns_start_reg, .. } => { program.emit_insn(Insn::Copy { src_reg: result_columns_start_reg + *column, dst_reg: target_register, amount: 0, }); Ok(target_register) } } } ast::Expr::RowId { database: _, table } => { let tbl_ref = referenced_tables.as_ref().unwrap().get(*table).unwrap(); let cursor_id = program.resolve_cursor_id(&tbl_ref.table_identifier); program.emit_insn(Insn::RowId { cursor_id, dest: target_register, }); Ok(target_register) } ast::Expr::InList { .. } => todo!(), ast::Expr::InSelect { .. } => todo!(), ast::Expr::InTable { .. } => todo!(), ast::Expr::IsNull(_) => todo!(), ast::Expr::Like { .. } => todo!(), ast::Expr::Literal(lit) => match lit { ast::Literal::Numeric(val) => { let maybe_int = val.parse::(); if let Ok(int_value) = maybe_int { program.emit_insn(Insn::Integer { value: int_value, dest: target_register, }); } else { // must be a float program.emit_insn(Insn::Real { value: val.parse()?, dest: target_register, }); } Ok(target_register) } ast::Literal::String(s) => { program.emit_insn(Insn::String8 { value: sanitize_string(s), dest: target_register, }); Ok(target_register) } ast::Literal::Blob(s) => { let bytes = s .as_bytes() .chunks_exact(2) .map(|pair| { // We assume that sqlite3-parser has already validated that // the input is valid hex string, thus unwrap is safe. let hex_byte = std::str::from_utf8(pair).unwrap(); u8::from_str_radix(hex_byte, 16).unwrap() }) .collect(); program.emit_insn(Insn::Blob { value: bytes, dest: target_register, }); Ok(target_register) } ast::Literal::Keyword(_) => todo!(), ast::Literal::Null => { program.emit_insn(Insn::Null { dest: target_register, dest_end: None, }); Ok(target_register) } ast::Literal::CurrentDate => todo!(), ast::Literal::CurrentTime => todo!(), ast::Literal::CurrentTimestamp => todo!(), }, ast::Expr::Name(_) => todo!(), ast::Expr::NotNull(_) => todo!(), ast::Expr::Parenthesized(exprs) => { if exprs.is_empty() { crate::bail_parse_error!("parenthesized expression with no arguments"); } if exprs.len() == 1 { translate_expr( program, referenced_tables, &exprs[0], target_register, resolver, )?; } else { // Parenthesized expressions with multiple arguments are reserved for special cases // like `(a, b) IN ((1, 2), (3, 4))`. todo!("TODO: parenthesized expression with multiple arguments not yet supported"); } Ok(target_register) } ast::Expr::Qualified(_, _) => { unreachable!("Qualified should be resolved to a Column before translation") } ast::Expr::Raise(_, _) => todo!(), ast::Expr::Subquery(_) => todo!(), ast::Expr::Unary(op, expr) => match (op, expr.as_ref()) { ( UnaryOperator::Negative | UnaryOperator::Positive, ast::Expr::Literal(ast::Literal::Numeric(numeric_value)), ) => { let maybe_int = numeric_value.parse::(); let multiplier = if let UnaryOperator::Negative = op { -1 } else { 1 }; if let Ok(value) = maybe_int { program.emit_insn(Insn::Integer { value: value * multiplier, dest: target_register, }); } else { program.emit_insn(Insn::Real { value: multiplier as f64 * numeric_value.parse::()?, dest: target_register, }); } Ok(target_register) } (UnaryOperator::Negative | UnaryOperator::Positive, _) => { let value = if let UnaryOperator::Negative = op { -1 } else { 1 }; let reg = program.alloc_register(); translate_expr(program, referenced_tables, expr, reg, resolver)?; let zero_reg = program.alloc_register(); program.emit_insn(Insn::Integer { value, dest: zero_reg, }); program.mark_last_insn_constant(); program.emit_insn(Insn::Multiply { lhs: zero_reg, rhs: reg, dest: target_register, }); Ok(target_register) } (UnaryOperator::BitwiseNot, ast::Expr::Literal(ast::Literal::Numeric(num_val))) => { let maybe_int = num_val.parse::(); if let Ok(val) = maybe_int { program.emit_insn(Insn::Integer { value: !val, dest: target_register, }); } else { let num_val = num_val.parse::()? as i64; program.emit_insn(Insn::Integer { value: !num_val, dest: target_register, }); } Ok(target_register) } (UnaryOperator::BitwiseNot, ast::Expr::Literal(ast::Literal::Null)) => { program.emit_insn(Insn::Null { dest: target_register, dest_end: None, }); Ok(target_register) } (UnaryOperator::BitwiseNot, _) => { let reg = program.alloc_register(); translate_expr(program, referenced_tables, expr, reg, resolver)?; program.emit_insn(Insn::BitNot { reg, dest: target_register, }); Ok(target_register) } _ => todo!(), }, ast::Expr::Variable(name) => { let index = program.parameters.push(name); program.emit_insn(Insn::Variable { index, dest: target_register, }); Ok(target_register) } } } /// Emits a whole insn for a function call. /// Assumes the number of parameters is valid for the given function. /// Returns the target register for the function. fn translate_function( program: &mut ProgramBuilder, args: &[ast::Expr], referenced_tables: Option<&[TableReference]>, resolver: &Resolver, target_register: usize, func_ctx: FuncCtx, ) -> Result { let start_reg = program.alloc_registers(args.len()); let mut current_reg = start_reg; for arg in args.iter() { translate_expr(program, referenced_tables, arg, current_reg, resolver)?; current_reg += 1; } program.emit_insn(Insn::Function { constant_mask: 0, start_reg, dest: target_register, func: func_ctx, }); Ok(target_register) } fn wrap_eval_jump_expr( program: &mut ProgramBuilder, insn: Insn, target_register: usize, if_true_label: BranchOffset, ) { program.emit_insn(Insn::Integer { value: 1, // emit True by default dest: target_register, }); program.emit_insn(insn); program.emit_insn(Insn::Integer { value: 0, // emit False if we reach this point (no jump) dest: target_register, }); program.preassign_label_to_next_insn(if_true_label); } fn wrap_eval_jump_expr_zero_or_null( program: &mut ProgramBuilder, insn: Insn, target_register: usize, if_true_label: BranchOffset, e1_reg: usize, e2_reg: usize, ) { program.emit_insn(Insn::Integer { value: 1, // emit True by default dest: target_register, }); program.emit_insn(insn); program.emit_insn(Insn::ZeroOrNull { rg1: e1_reg, rg2: e2_reg, dest: target_register, }); program.preassign_label_to_next_insn(if_true_label); } pub fn maybe_apply_affinity(col_type: Type, target_register: usize, program: &mut ProgramBuilder) { if col_type == Type::Real { program.emit_insn(Insn::RealAffinity { register: target_register, }) } } pub fn translate_and_mark( program: &mut ProgramBuilder, referenced_tables: Option<&[TableReference]>, expr: &ast::Expr, resolver: &Resolver, ) -> Result { let target_register = program.alloc_register(); translate_expr(program, referenced_tables, expr, target_register, resolver)?; if matches!(expr, ast::Expr::Literal(_)) { program.mark_last_insn_constant(); } Ok(target_register) } /// Get an appropriate name for an expression. /// If the query provides an alias (e.g. `SELECT a AS b FROM t`), use that (e.g. `b`). /// If the expression is a column from a table, use the column name (e.g. `a`). /// Otherwise we just use a generic fallback name (e.g. `expr_`). pub fn get_name( maybe_alias: Option<&ast::As>, expr: &ast::Expr, referenced_tables: &[TableReference], fallback: impl Fn() -> String, ) -> String { let alias = maybe_alias.map(|a| match a { ast::As::As(id) => id.0.clone(), ast::As::Elided(id) => id.0.clone(), }); if let Some(alias) = alias { return alias; } match expr { ast::Expr::Column { table, column, .. } => { let table_ref = referenced_tables.get(*table).unwrap(); table_ref.table.get_column_at(*column).name.clone() } _ => fallback(), } } /// Sanitaizes a string literal by removing single quote at front and back /// and escaping double single quotes pub fn sanitize_string(input: &str) -> String { input[1..input.len() - 1].replace("''", "'").to_string() }