From c66ae1d5c6b5342ed2dce0bbfa25ce6ba4ebe24b Mon Sep 17 00:00:00 2001
From: Dr-Carlos <dr.steven.carlos@gmail.com>
Date: Sat, 17 Dec 2022 20:31:59 +1030
Subject: [PATCH] _d: use expr_or_range to allow addresses or ranges

---
 shell/d.cpp      | 43 ++++++++++++++++++++++---------------------
 shell/parser.cpp | 13 ++++---------
 shell/parser.h   |  4 ++--
 3 files changed, 28 insertions(+), 32 deletions(-)

diff --git a/shell/d.cpp b/shell/d.cpp
index 2468ae1..d688680 100644
--- a/shell/d.cpp
+++ b/shell/d.cpp
@@ -77,25 +77,25 @@ struct _d_args
 
 static _d_args parse_d(Session &session, Parser &parser)
 {
+    _d_args args;
+
     if(!session.current_space)
         return {};
 
-    uint32_t address = session.current_space->cursor;
+    args.address = session.current_space->cursor;
+    args.range = {};
 
     if(!parser.at_end()) {
         auto v = parser.expr_or_range(session.current_space);
 
-        if(std::holds_alternative<long>(v)) {
-            address = std::get<long>(v);
-        }
-        else {
-            // TODO: Use an args struct etc. This is placeholder.
-            address = std::get<Range>(v).start;
-        }
+        if(std::holds_alternative<long>(v))
+            args.address = std::get<long>(v);
+        else
+            args.range = std::get<Range>(v);
     }
 
     parser.end();
-    return {address, {}};
+    return args;
 }
 
 void _d(Session &session, std::optional<uint32_t> address_opt,
@@ -105,19 +105,8 @@ void _d(Session &session, std::optional<uint32_t> address_opt,
         return;
     FxOS::Disassembly disasm(*session.current_space);
 
-    if(address_opt.has_value()) {
-        uint32_t address = address_opt.value();
 
-        if(address & 1) {
-            fmt::print("address 0x{:08x} is odd, starting at 0x{:08x}\n",
-                address, address + 1);
-            address++;
-        }
-
-        disassemble(session, disasm,
-            {"cfg", "pcrel", /*"constprop",*/ "syscall", "print"}, address);
-    }
-    else if(range_opt.has_value()) {
+    if(range_opt.has_value()) {
         Range range = range_opt.value();
         if(range.start & 1) {
             fmt::print("address 0x{:08x} is odd, starting at 0x{:08x}\n",
@@ -140,6 +129,18 @@ void _d(Session &session, std::optional<uint32_t> address_opt,
         disassemble(session, disasm,
             {"pcrel", /*"constprop",*/ "syscall", "print"}, -1);
     }
+    else if(address_opt.has_value()) {
+        uint32_t address = address_opt.value();
+
+        if(address & 1) {
+            fmt::print("address 0x{:08x} is odd, starting at 0x{:08x}\n",
+                address, address + 1);
+            address++;
+        }
+
+        disassemble(session, disasm,
+            {"cfg", "pcrel", /*"constprop",*/ "syscall", "print"}, address);
+    }
 }
 
 //---
diff --git a/shell/parser.cpp b/shell/parser.cpp
index 7a7e41d..c826ca2 100644
--- a/shell/parser.cpp
+++ b/shell/parser.cpp
@@ -306,14 +306,9 @@ void Parser::accept_options()
 // Parsing rules for expressions
 //---
 
-long Parser::atom(std::optional<Token> token)
+long Parser::atom()
 {
-    Token t;
-
-    if(token.has_value())
-        t = token.value();
-    else
-        t = expect({'$', '(', '-', T::SYMBOL, T::NUM, T::SYSCALL});
+    Token t = expect({'$', '(', '-', T::SYMBOL, T::NUM, T::SYSCALL});
 
     if(t.type == T::SYMBOL) {
         /* TODO: Specify the space that symbols are taken from */
@@ -397,10 +392,10 @@ long Parser::term()
     return v;
 }
 
-long Parser::expr(VirtualSpace *space, std::optional<Token> token)
+long Parser::expr(VirtualSpace *space)
 {
     m_expr_space = space;
-    long val = atom(token);
+    long val = atom();
     m_expr_space = nullptr;
     return val;
 }
diff --git a/shell/parser.h b/shell/parser.h
index 46660cc..693df9f 100644
--- a/shell/parser.h
+++ b/shell/parser.h
@@ -142,7 +142,7 @@ public:
 	/* Read a numerical constant, or an expression. Expression uses the space
 	   to access the program counter and query symbol values */
 	long num();
-	long expr(VirtualSpace *space, std::optional<Token> token={});
+	long expr(VirtualSpace *space);
 	/* Read a range; again $ and symbols are interpreted. If (before) and
 	   (after) are both specified, a single value will also be accepted, and
 	   the range [value-before, value+after) will be returned. */
@@ -194,7 +194,7 @@ private:
 	/* Parsing rules for expressions */
 	long term();
 	long factor();
-	long atom(std::optional<Token> token={});
+	long atom();
 
 	/* true if we're completing a partial command, false if we're parsing a
 	   finished one */