From 4e49913808da8593c332b230f0bc292537ac40d7 Mon Sep 17 00:00:00 2001
From: Nemo <me@captnemo.in>
Date: Tue, 2 Jun 2020 17:28:20 +0530
Subject: [PATCH] [07/Static] Implements static push/pop memory segment

---
 .../07/MemoryAccess/StaticTest/StaticTest.asm | 73 +++++++++++++++++++
 .../07/MemoryAccess/StaticTest/StaticTest.out |  2 +
 vm/CodeWriter.php                             | 27 +++++++
 vm/VMTranslator.php                           |  1 +
 4 files changed, 103 insertions(+)
 create mode 100644 projects/07/MemoryAccess/StaticTest/StaticTest.asm
 create mode 100644 projects/07/MemoryAccess/StaticTest/StaticTest.out

diff --git a/projects/07/MemoryAccess/StaticTest/StaticTest.asm b/projects/07/MemoryAccess/StaticTest/StaticTest.asm
new file mode 100644
index 0000000..754a1a1
--- /dev/null
+++ b/projects/07/MemoryAccess/StaticTest/StaticTest.asm
@@ -0,0 +1,73 @@
+@111 // push constant 111
+D=A
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push constant 111 (L0)
+@333 // push constant 333
+D=A
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push constant 333 (L1)
+@888 // push constant 888
+D=A
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push constant 888 (L2)
+@SP //pop static 8
+AM=M-1
+D=M
+@StaticTest.8
+M=D // end pop static 8 (L3)
+@SP //pop static 3
+AM=M-1
+D=M
+@StaticTest.3
+M=D // end pop static 3 (L4)
+@SP //pop static 1
+AM=M-1
+D=M
+@StaticTest.1
+M=D // end pop static 1 (L5)
+@StaticTest.3
+D=M
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push static 3 (L6)
+@StaticTest.1
+D=M
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push static 1 (L7)
+@SP // ==== sub ====
+A=M-1
+D=M
+A=A-1
+M=M-D
+@SP
+M=M-1 // end sub (L8)
+@StaticTest.8
+D=M
+@SP
+A=M
+M=D
+@SP
+M=M+1 // end push static 8 (L9)
+@SP // ==== add ====
+A=M-1
+D=M
+A=A-1
+M=D+M
+@SP
+M=M-1 // end add (L10)
+@72
+0;JMP
diff --git a/projects/07/MemoryAccess/StaticTest/StaticTest.out b/projects/07/MemoryAccess/StaticTest/StaticTest.out
new file mode 100644
index 0000000..2bc908b
--- /dev/null
+++ b/projects/07/MemoryAccess/StaticTest/StaticTest.out
@@ -0,0 +1,2 @@
+|RAM[256]|
+|   1110 |
diff --git a/vm/CodeWriter.php b/vm/CodeWriter.php
index 7044e6c..0558947 100644
--- a/vm/CodeWriter.php
+++ b/vm/CodeWriter.php
@@ -9,6 +9,10 @@ class CodeWriter {
     $this->file = fopen($outputFile, "w");
   }
 
+  function setInputFileName($inputFileName) {
+    $this->vm = basename($inputFileName, ".vm");
+  }
+
   function nextSourceLine() {
     $this->sourceLine += 1;
   }
@@ -185,6 +189,14 @@ class CodeWriter {
         ]);
         break;
 
+      case 'static':
+        $symbol = $this->resolveStatic($index);
+        $this->write([
+          $symbol,
+          "D=M"
+        ]);
+        break;
+
       case 'pointer':
         $register = $this->resolvePointer($index);
         $this->write([
@@ -239,6 +251,10 @@ class CodeWriter {
       ]);
   }
 
+  private function resolveStatic(Int $index) {
+    return "@{$this->vm}.$index";
+  }
+
   private function writePop(String $segment, Int $index) {
     switch ($segment) {
       // The address is given by LCL+INDEX
@@ -263,6 +279,17 @@ class CodeWriter {
         ]);
         break;
 
+      case 'static':
+        $symbol = $this->resolveStatic($index);
+        $this->write([
+          "@SP //pop $segment $index",
+          "AM=M-1",
+          "D=M",
+          $symbol,
+          "M=D // end pop $segment $index (L{$this->sourceLine})"
+        ]);
+        break;
+
       case 'pointer':
         // pointer points to a 2 register segment holding [this, that]
         $register = $this->resolvePointer($index);
diff --git a/vm/VMTranslator.php b/vm/VMTranslator.php
index 68b9e68..eea9d51 100644
--- a/vm/VMTranslator.php
+++ b/vm/VMTranslator.php
@@ -24,6 +24,7 @@ class VMTranslator {
   function translate() {
     foreach ($this->files as $file) {
       $parser = new Parser($file);
+      $this->writer->setInputFileName($file);
 
       foreach ($parser->commands() as $command) {
         $commandType = CommandType::fromName($command);