nac3core: codegen refactoring

- No longer check if the statement will return. Instead, we check if
  the current basic block is terminated, which is simpler and handles
  exception/break/continue better.
- Use invoke statement when unwind is needed.
- Moved codegen for a block of statements into a separate function.

nac3core/src/codegen/expr.rs

@@ -12,12 +12,12 @@ use crate::{
     typecheck::typedef::{FunSignature, FuncArg, Type, TypeEnum, Unifier},
 };
 use inkwell::{
-    types::{BasicType, BasicTypeEnum},
-    values::{BasicValueEnum, IntValue, PointerValue},
     AddressSpace,
+    types::{BasicType, BasicTypeEnum},
+    values::{BasicValueEnum, FunctionValue, IntValue, PointerValue}
 };
 use itertools::{chain, izip, zip, Itertools};
-use nac3parser::ast::{self, Boolop, Comprehension, Constant, Expr, ExprKind, Operator, StrRef};
+use nac3parser::ast::{self, Boolop, Comprehension, Constant, Expr, ExprKind, Location, Operator, StrRef};
 
 use super::CodeGenerator;
 
@@ -256,6 +256,25 @@ impl<'ctx, 'a> CodeGenContext<'ctx, 'a> {
             _ => unimplemented!(),
         }
     }
+
+    pub fn build_call_or_invoke(
+        &self,
+        fun: FunctionValue<'ctx>,
+        params: &[BasicValueEnum<'ctx>],
+        call_name: &str
+    ) -> Option<BasicValueEnum<'ctx>> {
+        if let Some(target) = self.unwind_target {
+            let current = self.builder.get_insert_block().unwrap().get_parent().unwrap();
+            let then_block = self.ctx.append_basic_block(current, &format!("after.{}", call_name));
+            let result = self.builder.build_invoke(fun, params, then_block, target, call_name).try_as_basic_value().left();
+            self.builder.position_at_end(then_block);
+            result
+        } else {
+            let param: Vec<_> = params.iter().map(|v| (*v).into()).collect();
+            self.builder.build_call(fun, &param, call_name).try_as_basic_value().left()
+        }
+    }
+
     pub fn gen_string<G: CodeGenerator, S: Into<String>>(
         &mut self,
         generator: &mut G,
@@ -404,7 +423,7 @@ pub fn gen_call<'ctx, 'a, G: CodeGenerator>(
                 }
                 // default value handling
                 for k in keys.into_iter() {
-                    mapping.insert(k.name, ctx.gen_symbol_val(&k.default_value.unwrap()).into());
+                    mapping.insert(k.name, ctx.gen_symbol_val(generator, &k.default_value.unwrap()).into());
                 }
                 // reorder the parameters
                 let mut real_params =
@@ -474,7 +493,8 @@ pub fn gen_call<'ctx, 'a, G: CodeGenerator>(
         };
         ctx.module.add_function(&symbol, fun_ty, None)
     });
-    ctx.builder.build_call(fun_val, &param_vals, "call").try_as_basic_value().left()
+
+    ctx.build_call_or_invoke(fun_val, &param_vals, "call")
 }
 
 pub fn destructure_range<'ctx, 'a>(
@@ -715,7 +735,7 @@ pub fn gen_expr<'ctx, 'a, G: CodeGenerator>(
     Some(match &expr.node {
         ExprKind::Constant { value, .. } => {
             let ty = expr.custom.unwrap();
-            ctx.gen_const(value, ty).into()
+            ctx.gen_const(generator, value, ty).into()
         }
         ExprKind::Name { id, .. } => match ctx.var_assignment.get(id) {
             Some((ptr, None, _)) => ctx.builder.build_load(*ptr, "load").into(),

nac3core/src/codegen/generator.rs

@@ -117,67 +117,45 @@ pub trait CodeGenerator {
 
     /// Generate code for a while expression.
     /// Return true if the while loop must early return
-    fn gen_while<'ctx, 'a>(
-        &mut self,
-        ctx: &mut CodeGenContext<'ctx, 'a>,
-        stmt: &Stmt<Option<Type>>,
-    ) -> bool
+    fn gen_while<'ctx, 'a>(&mut self, ctx: &mut CodeGenContext<'ctx, 'a>, stmt: &Stmt<Option<Type>>)
     where
         Self: Sized,
     {
         gen_while(self, ctx, stmt);
-        false
     }
 
     /// Generate code for a while expression.
     /// Return true if the while loop must early return
-    fn gen_for<'ctx, 'a>(
-        &mut self,
-        ctx: &mut CodeGenContext<'ctx, 'a>,
-        stmt: &Stmt<Option<Type>>,
-    ) -> bool
+    fn gen_for<'ctx, 'a>(&mut self, ctx: &mut CodeGenContext<'ctx, 'a>, stmt: &Stmt<Option<Type>>)
     where
         Self: Sized,
     {
         gen_for(self, ctx, stmt);
-        false
     }
 
     /// Generate code for an if expression.
     /// Return true if the statement must early return
-    fn gen_if<'ctx, 'a>(
-        &mut self,
-        ctx: &mut CodeGenContext<'ctx, 'a>,
-        stmt: &Stmt<Option<Type>>,
-    ) -> bool
+    fn gen_if<'ctx, 'a>(&mut self, ctx: &mut CodeGenContext<'ctx, 'a>, stmt: &Stmt<Option<Type>>)
     where
         Self: Sized,
     {
-        gen_if(self, ctx, stmt)
+        gen_if(self, ctx, stmt);
     }
 
-    fn gen_with<'ctx, 'a>(
-        &mut self,
-        ctx: &mut CodeGenContext<'ctx, 'a>,
-        stmt: &Stmt<Option<Type>>,
-    ) -> bool
+    fn gen_with<'ctx, 'a>(&mut self, ctx: &mut CodeGenContext<'ctx, 'a>, stmt: &Stmt<Option<Type>>)
     where
         Self: Sized,
     {
-        gen_with(self, ctx, stmt)
+        gen_with(self, ctx, stmt);
     }
 
     /// Generate code for a statement
     /// Return true if the statement must early return
-    fn gen_stmt<'ctx, 'a>(
-        &mut self,
-        ctx: &mut CodeGenContext<'ctx, 'a>,
-        stmt: &Stmt<Option<Type>>,
-    ) -> bool
+    fn gen_stmt<'ctx, 'a>(&mut self, ctx: &mut CodeGenContext<'ctx, 'a>, stmt: &Stmt<Option<Type>>)
     where
         Self: Sized,
     {
-        gen_stmt(self, ctx, stmt)
+        gen_stmt(self, ctx, stmt);
     }
 }
 

nac3core/src/codegen/mod.rs

@@ -14,7 +14,7 @@ use inkwell::{
     module::Module,
     passes::{PassManager, PassManagerBuilder},
     types::{BasicType, BasicTypeEnum},
-    values::{FunctionValue, PointerValue},
+    values::{BasicValueEnum, FunctionValue, PhiValue, PointerValue},
     AddressSpace, OptimizationLevel,
 };
 use itertools::Itertools;
@@ -60,11 +60,28 @@ pub struct CodeGenContext<'ctx, 'a> {
     pub primitives: PrimitiveStore,
     pub calls: Arc<HashMap<CodeLocation, CallId>>,
     pub registry: &'a WorkerRegistry,
+    // const string cache
+    pub const_strings: HashMap<String, BasicValueEnum<'ctx>>,
     // stores the alloca for variables
     pub init_bb: BasicBlock<'ctx>,
-    // where continue and break should go to respectively
     // the first one is the test_bb, and the second one is bb after the loop
-    pub loop_bb: Option<(BasicBlock<'ctx>, BasicBlock<'ctx>)>,
+    pub loop_target: Option<(BasicBlock<'ctx>, BasicBlock<'ctx>)>,
+    // unwind target bb
+    pub unwind_target: Option<BasicBlock<'ctx>>,
+    // return target bb, just emit ret if no such target
+    pub return_target: Option<BasicBlock<'ctx>>,
+    pub return_buffer: Option<PointerValue<'ctx>>,
+    // outer finally block function
+    pub outer_final: Option<(PointerValue<'ctx>, Vec<BasicBlock<'ctx>>, Vec<BasicBlock<'ctx>>)>,
+    // outer catch clauses
+    pub outer_catch_clauses:
+        Option<(Vec<Option<BasicValueEnum<'ctx>>>, BasicBlock<'ctx>, PhiValue<'ctx>)>,
+}
+
+impl<'ctx, 'a> CodeGenContext<'ctx, 'a> {
+    pub fn is_terminated(&self) -> bool {
+        self.builder.get_insert_block().unwrap().get_terminator().is_some()
+    }
 }
 
 type Fp = Box<dyn Fn(&Module) + Send + Sync>;
@@ -182,7 +199,7 @@ impl WorkerRegistry {
     fn worker_thread<G: CodeGenerator>(&self, generator: &mut G, f: Arc<WithCall>) {
         let context = Context::create();
         let mut builder = context.create_builder();
-        let mut module = context.create_module(generator.get_name());
+        let module = context.create_module(generator.get_name());
 
         let pass_builder = PassManagerBuilder::create();
         pass_builder.set_optimization_level(OptimizationLevel::Default);
@@ -190,10 +207,12 @@ impl WorkerRegistry {
         pass_builder.populate_function_pass_manager(&passes);
 
         while let Some(task) = self.receiver.recv().unwrap() {
-            let result = gen_func(&context, generator, self, builder, module, task);
+            let tmp_module = context.create_module("tmp");
+            let result = gen_func(&context, generator, self, builder, tmp_module, task);
             builder = result.0;
-            module = result.1;
             passes.run_on(&result.2);
+            module.link_in_module(result.1).unwrap();
+            // module = result.1;
             *self.task_count.lock() -= 1;
             self.wait_condvar.notify_all();
         }
@@ -235,20 +254,26 @@ fn get_llvm_type<'ctx>(
     // we assume the type cache should already contain primitive types,
     // and they should be passed by value instead of passing as pointer.
     type_cache.get(&unifier.get_representative(ty)).cloned().unwrap_or_else(|| {
-        let ty = unifier.get_ty(ty);
-        match &*ty {
+        let ty_enum = unifier.get_ty(ty);
+        let result = match &*ty_enum {
             TObj { obj_id, fields, .. } => {
+                // check to avoid treating primitives as classes
+                if obj_id.0 <= 7 {
+                    unreachable!();
+                }
                 // a struct with fields in the order of declaration
                 let top_level_defs = top_level.definitions.read();
                 let definition = top_level_defs.get(obj_id.0).unwrap();
-                let ty = if let TopLevelDef::Class { fields: fields_list, .. } = &*definition.read()
+                let ty = if let TopLevelDef::Class { name, fields: fields_list, .. } = &*definition.read()
                 {
+                    let struct_type = ctx.opaque_struct_type(&name.to_string());
                     let fields = fields.borrow();
                     let fields = fields_list
                         .iter()
                         .map(|f| get_llvm_type(ctx, generator, unifier, top_level, type_cache, fields[&f.0].0))
                         .collect_vec();
-                    ctx.struct_type(&fields, false).ptr_type(AddressSpace::Generic).into()
+                    struct_type.set_body(&fields, false);
+                    struct_type.ptr_type(AddressSpace::Generic).into()
                 } else {
                     unreachable!()
                 };
@@ -270,8 +295,10 @@ fn get_llvm_type<'ctx>(
                 ctx.struct_type(&fields, false).ptr_type(AddressSpace::Generic).into()
             }
             TVirtual { .. } => unimplemented!(),
-            _ => unreachable!("{}", ty.get_type_name()),
-        }
+            _ => unreachable!("{}", ty_enum.get_type_name()),
+        };
+        type_cache.insert(unifier.get_representative(ty), result);
+        result
     })
 }
 
@@ -415,6 +442,7 @@ pub fn gen_func<'ctx, G: CodeGenerator>(
         builder.build_store(alloca, param);
         var_assignment.insert(arg.name, (alloca, None, 0));
     }
+    let return_buffer = fn_type.get_return_type().map(|v| builder.build_alloca(v, "$ret"));
     let static_values = {
         let store = registry.static_value_store.lock();
         store.store[task.id].clone()
@@ -432,7 +460,13 @@ pub fn gen_func<'ctx, G: CodeGenerator>(
         resolver: task.resolver,
         top_level: top_level_ctx.as_ref(),
         calls: task.calls,
-        loop_bb: None,
+        loop_target: None,
+        return_target: None,
+        return_buffer,
+        unwind_target: None,
+        outer_final: None,
+        outer_catch_clauses: None,
+        const_strings: Default::default(),
         registry,
         var_assignment,
         type_cache,
@@ -444,15 +478,14 @@ pub fn gen_func<'ctx, G: CodeGenerator>(
         static_value_store,
     };
 
-    let mut returned = false;
     for stmt in task.body.iter() {
-        returned = generator.gen_stmt(&mut code_gen_context, stmt);
-        if returned {
+        generator.gen_stmt(&mut code_gen_context, stmt);
+        if code_gen_context.is_terminated() {
             break;
         }
     }
     // after static analysis, only void functions can have no return at the end.
-    if !returned {
+    if !code_gen_context.is_terminated() {
         code_gen_context.builder.build_return(None);
     }
 

nac3core/src/codegen/stmt.rs

@@ -6,13 +6,17 @@ use super::{
 };
 use crate::{
     codegen::expr::gen_binop_expr,
-    typecheck::typedef::{Type, TypeEnum},
+    toplevel::{DefinitionId, TopLevelDef},
+    typecheck::typedef::{Type, TypeEnum, FunSignature}
 };
 use inkwell::{
+    attributes::{Attribute, AttributeLoc},
+    basic_block::BasicBlock,
     types::BasicTypeEnum,
-    values::{BasicValue, BasicValueEnum, PointerValue},
+    values::{BasicValue, BasicValueEnum, FunctionValue, PointerValue},
+    IntPredicate::EQ,
 };
-use nac3parser::ast::{Expr, ExprKind, Stmt, StmtKind};
+use nac3parser::ast::{ExcepthandlerKind, Expr, ExprKind, Location, Stmt, StmtKind, StrRef, Constant};
 use std::convert::TryFrom;
 
 pub fn gen_var<'ctx, 'a>(
@@ -173,7 +177,7 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
         let orelse_bb =
             if orelse.is_empty() { cont_bb } else { ctx.ctx.append_basic_block(current, "orelse") };
         // store loop bb information and restore it later
-        let loop_bb = ctx.loop_bb.replace((test_bb, cont_bb));
+        let loop_bb = ctx.loop_target.replace((test_bb, cont_bb));
 
         let iter_val = generator.gen_expr(ctx, iter).unwrap().to_basic_value_enum(ctx, generator);
         if ctx.unifier.unioned(iter.custom.unwrap(), ctx.primitives.range) {
@@ -234,23 +238,23 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
             generator.gen_assign(ctx, target, val.into());
         }
 
-        for stmt in body.iter() {
-            generator.gen_stmt(ctx, stmt);
-        }
+        gen_block(generator, ctx, body.iter());
         for (k, (_, _, counter)) in var_assignment.iter() {
             let (_, static_val, counter2) = ctx.var_assignment.get_mut(k).unwrap();
             if counter != counter2 {
                 *static_val = None;
             }
         }
+        if !ctx.is_terminated() {
             ctx.builder.build_unconditional_branch(test_bb);
+        }
         if !orelse.is_empty() {
             ctx.builder.position_at_end(orelse_bb);
-            for stmt in orelse.iter() {
-                generator.gen_stmt(ctx, stmt);
-            }
+            gen_block(generator, ctx, orelse.iter());
+            if !ctx.is_terminated() {
                 ctx.builder.build_unconditional_branch(cont_bb);
             }
+        }
         for (k, (_, _, counter)) in var_assignment.iter() {
             let (_, static_val, counter2) = ctx.var_assignment.get_mut(k).unwrap();
             if counter != counter2 {
@@ -258,7 +262,7 @@ pub fn gen_for<'ctx, 'a, G: CodeGenerator>(
             }
         }
         ctx.builder.position_at_end(cont_bb);
-        ctx.loop_bb = loop_bb;
+        ctx.loop_target = loop_bb;
     } else {
         unreachable!()
     }
@@ -282,7 +286,7 @@ pub fn gen_while<'ctx, 'a, G: CodeGenerator>(
         let orelse_bb =
             if orelse.is_empty() { cont_bb } else { ctx.ctx.append_basic_block(current, "orelse") };
         // store loop bb information and restore it later
-        let loop_bb = ctx.loop_bb.replace((test_bb, cont_bb));
+        let loop_bb = ctx.loop_target.replace((test_bb, cont_bb));
         ctx.builder.build_unconditional_branch(test_bb);
         ctx.builder.position_at_end(test_bb);
         let test = generator.gen_expr(ctx, test).unwrap().to_basic_value_enum(ctx, generator);
@@ -292,23 +296,23 @@ pub fn gen_while<'ctx, 'a, G: CodeGenerator>(
             unreachable!()
         };
         ctx.builder.position_at_end(body_bb);
-        for stmt in body.iter() {
-            generator.gen_stmt(ctx, stmt);
-        }
+        gen_block(generator, ctx, body.iter());
         for (k, (_, _, counter)) in var_assignment.iter() {
             let (_, static_val, counter2) = ctx.var_assignment.get_mut(k).unwrap();
             if counter != counter2 {
                 *static_val = None;
             }
         }
+        if !ctx.is_terminated() {
             ctx.builder.build_unconditional_branch(test_bb);
+        }
         if !orelse.is_empty() {
             ctx.builder.position_at_end(orelse_bb);
-            for stmt in orelse.iter() {
-                generator.gen_stmt(ctx, stmt);
-            }
+            gen_block(generator, ctx, orelse.iter());
+            if !ctx.is_terminated() {
                 ctx.builder.build_unconditional_branch(cont_bb);
             }
+        }
         for (k, (_, _, counter)) in var_assignment.iter() {
             let (_, static_val, counter2) = ctx.var_assignment.get_mut(k).unwrap();
             if counter != counter2 {
@@ -316,7 +320,7 @@ pub fn gen_while<'ctx, 'a, G: CodeGenerator>(
             }
         }
         ctx.builder.position_at_end(cont_bb);
-        ctx.loop_bb = loop_bb;
+        ctx.loop_target = loop_bb;
     } else {
         unreachable!()
     }
@@ -326,7 +330,7 @@ pub fn gen_if<'ctx, 'a, G: CodeGenerator>(
     generator: &mut G,
     ctx: &mut CodeGenContext<'ctx, 'a>,
     stmt: &Stmt<Option<Type>>,
-) -> bool {
+) {
     if let StmtKind::If { test, body, orelse, .. } = &stmt.node {
         // var_assignment static values may be changed in another branch
         // if so, remove the static value as it may not be correct in this branch
@@ -352,13 +356,7 @@ pub fn gen_if<'ctx, 'a, G: CodeGenerator>(
             unreachable!()
         };
         ctx.builder.position_at_end(body_bb);
-        let mut exited = false;
-        for stmt in body.iter() {
-            exited = generator.gen_stmt(ctx, stmt);
-            if exited {
-                break;
-            }
-        }
+        gen_block(generator, ctx, body.iter());
         for (k, (_, _, counter)) in var_assignment.iter() {
             let (_, static_val, counter2) = ctx.var_assignment.get_mut(k).unwrap();
             if counter != counter2 {
@@ -366,32 +364,22 @@ pub fn gen_if<'ctx, 'a, G: CodeGenerator>(
             }
         }
 
-        if !exited {
+        if !ctx.is_terminated() {
             if cont_bb.is_none() {
                 cont_bb = Some(ctx.ctx.append_basic_block(current, "cont"));
             }
             ctx.builder.build_unconditional_branch(cont_bb.unwrap());
         }
-        let then_exited = exited;
-        let else_exited = if !orelse.is_empty() {
-            exited = false;
+        if !orelse.is_empty() {
             ctx.builder.position_at_end(orelse_bb);
-            for stmt in orelse.iter() {
-                exited = generator.gen_stmt(ctx, stmt);
-                if exited {
-                    break;
-                }
-            }
-            if !exited {
+            gen_block(generator, ctx, orelse.iter());
+            if !ctx.is_terminated() {
                 if cont_bb.is_none() {
                     cont_bb = Some(ctx.ctx.append_basic_block(current, "cont"));
                 }
                 ctx.builder.build_unconditional_branch(cont_bb.unwrap());
             }
-            exited
-        } else {
-            false
-        };
+        }
         if let Some(cont_bb) = cont_bb {
             ctx.builder.position_at_end(cont_bb);
         }
@@ -401,7 +389,11 @@ pub fn gen_if<'ctx, 'a, G: CodeGenerator>(
                 *static_val = None;
             }
         }
-        then_exited && else_exited
+    } else {
+        unreachable!()
+    }
+}
+
 pub fn exn_constructor<'ctx, 'a>(
     ctx: &mut CodeGenContext<'ctx, 'a>,
     obj: Option<(Type, ValueEnum<'ctx>)>,
@@ -481,23 +473,37 @@ pub fn gen_with<'ctx, 'a, G: CodeGenerator>(
     unimplemented!()
 }
 
+pub fn gen_return<'ctx, 'a, G: CodeGenerator>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, 'a>,
+    value: &Option<Box<Expr<Option<Type>>>>,
+) {
+    let value = value
+        .as_ref()
+        .map(|v| generator.gen_expr(ctx, v).unwrap().to_basic_value_enum(ctx, generator));
+    if let Some(return_target) = ctx.return_target {
+        if let Some(value) = value {
+            ctx.builder.build_store(ctx.return_buffer.unwrap(), value);
+        }
+        ctx.builder.build_unconditional_branch(return_target);
+    } else {
+        let value = value.as_ref().map(|v| v as &dyn BasicValue);
+        ctx.builder.build_return(value);
+    }
+}
+
 pub fn gen_stmt<'ctx, 'a, G: CodeGenerator>(
     generator: &mut G,
     ctx: &mut CodeGenContext<'ctx, 'a>,
     stmt: &Stmt<Option<Type>>,
-) -> bool {
+) {
     match &stmt.node {
         StmtKind::Pass { .. } => {}
         StmtKind::Expr { value, .. } => {
             generator.gen_expr(ctx, value);
         }
         StmtKind::Return { value, .. } => {
-            let value = value
-                .as_ref()
-                .map(|v| generator.gen_expr(ctx, v).unwrap().to_basic_value_enum(ctx, generator));
-            let value = value.as_ref().map(|v| v as &dyn BasicValue);
-            ctx.builder.build_return(value);
-            return true;
+            gen_return(generator, ctx, value);
         }
         StmtKind::AnnAssign { target, value, .. } => {
             if let Some(value) = value {
@@ -512,17 +518,15 @@ pub fn gen_stmt<'ctx, 'a, G: CodeGenerator>(
             }
         }
         StmtKind::Continue { .. } => {
-            ctx.builder.build_unconditional_branch(ctx.loop_bb.unwrap().0);
-            return true;
+            ctx.builder.build_unconditional_branch(ctx.loop_target.unwrap().0);
         }
         StmtKind::Break { .. } => {
-            ctx.builder.build_unconditional_branch(ctx.loop_bb.unwrap().1);
-            return true;
+            ctx.builder.build_unconditional_branch(ctx.loop_target.unwrap().1);
         }
-        StmtKind::If { .. } => return generator.gen_if(ctx, stmt),
-        StmtKind::While { .. } => return generator.gen_while(ctx, stmt),
-        StmtKind::For { .. } => return generator.gen_for(ctx, stmt),
-        StmtKind::With { .. } => return generator.gen_with(ctx, stmt),
+        StmtKind::If { .. } => generator.gen_if(ctx, stmt),
+        StmtKind::While { .. } => generator.gen_while(ctx, stmt),
+        StmtKind::For { .. } => generator.gen_for(ctx, stmt),
+        StmtKind::With { .. } => generator.gen_with(ctx, stmt),
         StmtKind::AugAssign { target, op, value, .. } => {
             let value = gen_binop_expr(generator, ctx, target, op, value);
             generator.gen_assign(ctx, target, value);
@@ -530,4 +534,15 @@ pub fn gen_stmt<'ctx, 'a, G: CodeGenerator>(
         _ => unimplemented!(),
     };
     false
+pub fn gen_block<'ctx, 'a, 'b, G: CodeGenerator, I: Iterator<Item = &'b Stmt<Option<Type>>>>(
+    generator: &mut G,
+    ctx: &mut CodeGenContext<'ctx, 'a>,
+    stmts: I,
+) {
+    for stmt in stmts {
+        generator.gen_stmt(ctx, stmt);
+        if ctx.is_terminated() {
+            break;
+        }
+    }
 }