From c9a478f7df54a0b84a9ad4cdaee6d5b6e978ecc8 Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Thu, 24 Aug 2023 09:33:27 +0000
Subject: [PATCH] main: add support for C source code output

---
 README.rst |  7 ++++++
 main.cpp   | 63 ++++++++++++++++++++++++++++++++++++++----------------
 2 files changed, 52 insertions(+), 18 deletions(-)

diff --git a/README.rst b/README.rst
index bfd1227..06d30ba 100644
--- a/README.rst
+++ b/README.rst
@@ -10,6 +10,13 @@ Usage:
    
    scu-dsp-asm input-file.asm output-file.bin
 
+Alternately, use the ``-s`` (source code) command-line argument to
+emit a C-syntax source code fragment:
+   
+.. code::   
+
+   scu-dsp-asm -s input-file.asm output-file.inc
+
 If no arguments are given, scu-dsp-asm starts a basic REPL.
 
 Wherever possible, scu-dsp-asm attempts to preserve compatibility with
diff --git a/main.cpp b/main.cpp
index d9aba38..f746505 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,6 +4,8 @@
 #include <optional>
 #include <bitset>
 #include <sstream>
+#include <array>
+#include <iomanip>
 
 #include "lexer.hpp"
 #include "token.hpp"
@@ -18,18 +20,35 @@ bool had_error = false;
 
 }
 
-static void write(std::ostream& os, uint32_t v)
+template <typename T>
+static std::array<T, 4> uint32_be(uint32_t v)
 {
-  const char out[4] = {
-    static_cast<char>((v >> 24) & 0xff),
-    static_cast<char>((v >> 16) & 0xff),
-    static_cast<char>((v >> 8 ) & 0xff),
-    static_cast<char>((v >> 0 ) & 0xff),
+  return {
+    static_cast<T>((v >> 24) & 0xff),
+    static_cast<T>((v >> 16) & 0xff),
+    static_cast<T>((v >> 8 ) & 0xff),
+    static_cast<T>((v >> 0 ) & 0xff),
   };
-  os.write(out, 4);
 }
 
-static void run(std::ostream& os, std::string source)
+static void write_hex(std::ostream& os, uint32_t v)
+{
+  const auto out = uint32_be<int>(v);
+  os << std::setfill('0') << std::right << std::hex
+     << "0x"
+     << std::setw(2) << out[0]
+     << std::setw(2) << out[1]
+     << std::setw(2) << out[2]
+     << std::setw(2) << out[3] << ',' << std::endl;
+}
+
+static void write_raw(std::ostream& os, uint32_t v)
+{
+  const auto out = uint32_be<char>(v);
+  os.write(out.data(), 4);
+}
+
+static void run(std::ostream& os, std::string source, bool hex_output, bool verbose)
 {
   using namespace dsp;
 
@@ -43,16 +62,19 @@ static void run(std::ostream& os, std::string source)
   ast::variables_t variables;
   ast::resolver_t resolver(pc, variables);
   while (auto stmt_o = pass1.statement()) {
-    (*stmt_o)->accept(&printer);
-    std::cout << std::endl << std::flush;
+    if (verbose) {
+      (*stmt_o)->accept(&printer);
+      std::cout << std::endl << std::flush;
+    }
     (*stmt_o)->accept(&resolver);
   }
   ast::emitter_t emitter(variables);
   while (auto stmt_o = pass2.statement()) {
     uint32_t output = (*stmt_o)->accept(&emitter);
     if (output != 0xffff'ffff) {
-      std::cout << std::bitset<32>(output) << std::endl;
-      write(os, output);
+      //std::cout << std::bitset<32>(output) << std::endl;
+      if (hex_output) write_hex(os, output);
+      else            write_raw(os, output);
     }
   }
 }
@@ -63,13 +85,12 @@ static void run_prompt()
   std::string line;
   std::cout << prompt << std::flush;
   while (std::getline(std::cin, line)) {
-    std::ostringstream os;
-    run(os, line);
+    run(std::cout, line, true, true);
     std::cout << prompt << std::flush;
   }
 }
 
-static int run_file(char const * const input_filename, char const * const output_filename)
+static int run_file(char const * const input_filename, char const * const output_filename, bool hex_output)
 {
   std::ifstream is {input_filename, std::ios::binary | std::ios::ate};
   if (!is.is_open()) {
@@ -85,7 +106,7 @@ static int run_file(char const * const input_filename, char const * const output
   }
 
   std::ostringstream os;
-  run(os, buf);
+  run(os, buf, hex_output, false);
 
   if (!dsp::had_error) {
     std::ofstream ofs {output_filename, std::ios::binary | std::ios::trunc};
@@ -101,11 +122,17 @@ static int run_file(char const * const input_filename, char const * const output
 
 int main(const int argc, char const * const argv[])
 {
+  const std::string c_source("-s");
+
   switch (argc) {
   case 1: run_prompt(); return dsp::had_error;
-  case 3: return run_file(argv[1], argv[2]);
+  case 3: return run_file(argv[1], argv[2], false);
+  case 4:
+    if (c_source.compare(argv[1]) == 0) return run_file(argv[2], argv[3], true);
+    else
+      [[fallthrough]];
   default:
-    std::cerr << "Usage: " << argv[0] << " [input-filename output-filename]" << std::endl;
+    std::cerr << "Usage: " << argv[0] << " [[-s] input-filename output-filename]" << std::endl;
     return -1;
   }
 }