From 7504b81b2d93240de80c6f68861d87df46466fd8 Mon Sep 17 00:00:00 2001
From: Alek Ratzloff <alekratz@gmail.com>
Date: Mon, 10 Feb 2020 18:02:44 -0500
Subject: [PATCH] Require assembler sections to specify where in virtual memory
 they begin

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
---
 src/main.rs                   | 11 +++++------
 src/vm/obj/assemble/mod.rs    | 13 ++++++-------
 src/vm/obj/syn/ast.rs         |  4 ++--
 src/vm/obj/syn/parser.lalrpop |  4 ++--
 4 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index c7230c8..fc8bab5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -31,6 +31,7 @@ fn main() -> Result<()> {
         }
     };
     let obj = vm::obj::obj::Object::try_from(&ast)?;
+    //dump(&obj)?;
     let mut vm = vm::vm::Vm::new();
     vm.load_object(obj, 1024 * 1024 * 64)?; // 64mb
     let status = vm.run()?;
@@ -39,23 +40,21 @@ fn main() -> Result<()> {
 }
 
 
-    /*
-fn dump(obj: &Object) {
+fn dump(obj: &vm::obj::obj::Object) -> Result<()> {
     use vm::obj::obj::Section;
     use vm::visit::VisitInst;
     let mut stdout = io::stdout();
     for section in &obj.sections {
         let mut disasm = match section {
-            Section::Code { start, contents, .. }
-            | Section::Data { start, contents, .. } => {
+            Section::Code { start, contents, .. } => {
                 vm::disassemble::Disassemble::new(&mut stdout, contents, *start)
             }
-            Section::Meta { .. } => continue,
+            Section::Meta { .. } | Section::Data { .. } => continue,
         };
         while !disasm.is_done() {
             disasm.visit_inst()?;
         }
         println!();
     }
+    Ok(())
 }
-    */
diff --git a/src/vm/obj/assemble/mod.rs b/src/vm/obj/assemble/mod.rs
index 9532c45..cb73def 100644
--- a/src/vm/obj/assemble/mod.rs
+++ b/src/vm/obj/assemble/mod.rs
@@ -38,7 +38,6 @@ impl<'a> Assemble<'a> {
     }
 
     pub fn assemble(&mut self) -> Result<Object> {
-        let mut pos = 0;
         let mut sections = Vec::new();
 
         // gather global symbols
@@ -78,11 +77,9 @@ impl<'a> Assemble<'a> {
                         }
                     }
                     let (start, end) = match org {
-                        Some(SectionOrg::Start(start)) => (*start, start + bytes.len() as u64),
-                        Some(SectionOrg::Range(start, end)) => (*start, *end),
-                        None => (pos, pos + bytes.len() as u64),
+                        SectionOrg::Start(start) => (*start, start + bytes.len() as u64),
+                        SectionOrg::Range(start, end) => (*start, *end),
                     };
-                    pos = end;
 
                     let section = match block {
                         SectionBlock::Data { .. } => Section::Data {
@@ -121,10 +118,12 @@ impl<'a> Assemble<'a> {
 
     fn gather_symbols(block: &SectionBlock, export: bool) -> Result<HashMap<String, u64>> {
         match block {
-            SectionBlock::Data { body, .. } | SectionBlock::Code { body, .. } => {
+            SectionBlock::Data { org, body, .. } | SectionBlock::Code { org, body, .. } => {
                 let mut exports = HashSet::new();
                 let mut labels = HashMap::new();
-                let mut pos = 0;
+                let mut pos = match org {
+                    SectionOrg::Start(start) | SectionOrg::Range(start, _) => (*start) as usize,
+                };
                 for line in body.iter() {
                     match line {
                         Line::Inst(inst) => {
diff --git a/src/vm/obj/syn/ast.rs b/src/vm/obj/syn/ast.rs
index e6709d4..fe09b44 100644
--- a/src/vm/obj/syn/ast.rs
+++ b/src/vm/obj/syn/ast.rs
@@ -3,11 +3,11 @@ use crate::vm::{inst::*, reg::Reg};
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SectionBlock {
     Data {
-        org: Option<SectionOrg>,
+        org: SectionOrg,
         body: Vec<Line>,
     },
     Code {
-        org: Option<SectionOrg>,
+        org: SectionOrg,
         body: Vec<Line>,
     },
     Meta {
diff --git a/src/vm/obj/syn/parser.lalrpop b/src/vm/obj/syn/parser.lalrpop
index 76fcd95..c3de298 100644
--- a/src/vm/obj/syn/parser.lalrpop
+++ b/src/vm/obj/syn/parser.lalrpop
@@ -82,11 +82,11 @@ SectionOrg: SectionOrg = {
 }
 
 Section: SectionBlock = {
-    "data" <org:SectionOrg?> "{" <body:Line*> "}" => {
+    "data" <org:SectionOrg> "{" <body:Line*> "}" => {
         SectionBlock::Data { org, body }
     },
 
-    "code" <org:SectionOrg?> "{" <body:Line*> "}" => {
+    "code" <org:SectionOrg> "{" <body:Line*> "}" => {
         SectionBlock::Code { org, body }
     },