From 7a8b8e46eb992565493247d069c187ae1ccdbb2e Mon Sep 17 00:00:00 2001
From: Jeremy Wall <jeremy@marzhillstudios.com>
Date: Mon, 25 May 2020 13:26:57 -0400
Subject: [PATCH] DEV: Link all the packages upfront

---
 src/build/mod.rs              | 44 ++++++++++++++++++++++++++++-------
 src/build/opcode/mod.rs       |  2 +-
 src/build/opcode/runtime.rs   |  2 ++
 src/build/opcode/translate.rs |  8 +++----
 4 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/src/build/mod.rs b/src/build/mod.rs
index f1c9651..337d09a 100644
--- a/src/build/mod.rs
+++ b/src/build/mod.rs
@@ -14,8 +14,7 @@
 
 //! The build stage of the ucg compiler.
 use std::cell::RefCell;
-use std::collections::HashMap;
-use std::convert::TryInto;
+use std::collections::{BTreeSet, HashMap};
 use std::error::Error;
 use std::path::PathBuf;
 use std::process;
@@ -28,6 +27,7 @@ use rustyline::error::ReadlineError;
 use simple_error;
 
 use crate::ast::*;
+#[macro_use]
 use crate::build::opcode::pointer::OpPointer;
 use crate::build::opcode::translate;
 use crate::build::opcode::translate::OpsMap;
@@ -168,7 +168,34 @@ where
         self.validate_mode = true;
     }
 
+    fn link_ops(&self, ops: &OpPointer) -> BuildResult {
+        let mut links = Vec::new();
+        for (link, pos) in &ops.pos_map.links {
+            links.push((link.clone(), pos.clone()));
+        }
+        let mut found = BTreeSet::new();
+        loop {
+            let (link, path_pos) = match links.pop() {
+                Some(t) => t,
+                None => break,
+            };
+            if found.contains(&link) {
+                continue;
+            }
+            let ops = match self.environment.borrow_mut().get_ops_for_path(link.clone()) {
+                Ok(ops) => ops,
+                Err(e) => return Err(Box::new(e.with_pos(path_pos))),
+            };
+            found.insert(link);
+            for (link, pos) in &ops.pos_map.links {
+                links.push((link.clone(), pos.clone()));
+            }
+        }
+        Ok(())
+    }
+
     fn eval_ops(&mut self, ops: OpPointer, path: Option<PathBuf>) -> BuildResult {
+        self.link_ops(&ops)?;
         let mut vm = VM::with_pointer(self.strict, ops, &self.working_dir);
         if path.is_some() {
             vm.set_path(path.unwrap());
@@ -303,13 +330,12 @@ where
     pub fn eval_expr(&mut self, expr: Expression) -> Result<Rc<Val>, Box<dyn Error>> {
         let ops_map =
             translate::AST::translate(vec![Statement::Expression(expr)], &self.working_dir);
-        let mut vm = VM::new(self.strict, Rc::new(ops_map), &self.working_dir);
-        if self.validate_mode {
-            vm.enable_validate_mode();
-        }
-        vm.run(self.environment)?;
-        if let Some((val, _)) = vm.last.clone() {
-            return Ok(Rc::new(val.try_into()?));
+        self.eval_ops(
+            OpPointer::new(Rc::new(ops_map)),
+            Some(self.working_dir.clone()),
+        )?;
+        if let Some(val) = &self.last {
+            return Ok(val.clone());
         }
         unreachable!();
     }
diff --git a/src/build/opcode/mod.rs b/src/build/opcode/mod.rs
index 42d46e6..4e25627 100644
--- a/src/build/opcode/mod.rs
+++ b/src/build/opcode/mod.rs
@@ -18,7 +18,7 @@ mod debug;
 mod display;
 pub mod environment;
 #[macro_use]
-mod error;
+pub mod error;
 mod convert;
 pub mod pointer;
 mod runtime;
diff --git a/src/build/opcode/runtime.rs b/src/build/opcode/runtime.rs
index 7f90628..9ca3331 100644
--- a/src/build/opcode/runtime.rs
+++ b/src/build/opcode/runtime.rs
@@ -194,6 +194,8 @@ impl Builtins {
         let path = stack.pop();
         if let Some((val, path_pos)) = path {
             if let &Value::P(Str(ref path)) = val.as_ref() {
+                // FIXME(jwall): Most of this is no longer necessary since
+                //   we do it before hand at the linker step.
                 // TODO(jwall): A bit hacky we should probably change import stacks to be pathbufs.
                 let normalized =
                     decorate_error!(path_pos => self.normalize_path(base_path, false, path))?;
diff --git a/src/build/opcode/translate.rs b/src/build/opcode/translate.rs
index 73225e4..bc38fff 100644
--- a/src/build/opcode/translate.rs
+++ b/src/build/opcode/translate.rs
@@ -29,7 +29,7 @@ pub struct AST();
 pub struct OpsMap {
     pub ops: Vec<Op>,
     pub pos: Vec<Position>,
-    pub links: BTreeMap<String, usize>,
+    pub links: BTreeMap<String, Position>,
 }
 
 impl OpsMap {
@@ -47,8 +47,8 @@ impl OpsMap {
         self
     }
 
-    pub fn add_link(&mut self, path: String) {
-        self.links.insert(path, self.len() - 1);
+    pub fn add_link(&mut self, path: String, pos: Position) {
+        self.links.insert(path, pos);
     }
 
     pub fn len(&self) -> usize {
@@ -444,9 +444,9 @@ impl AST {
             }
             Expression::Import(def) => {
                 let link_path = def.path.fragment.clone();
+                ops.add_link(link_path, def.path.pos.clone());
                 ops.push(Op::Val(Primitive::Str(def.path.fragment)), def.path.pos);
                 ops.push(Op::Runtime(Hook::Import), def.pos);
-                ops.add_link(link_path);
             }
             Expression::Include(def) => {
                 ops.push(Op::Val(Primitive::Str(def.typ.fragment)), def.typ.pos);