Refactor command parameter handling

Author: Your Name

DEVELOPMENT.md

@@ -109,31 +109,26 @@ export class Var {
 Similarly, the `run` method of each commandlet is expected to return a `Var` type which can subsequently be referenced by the user using the `ret` keyword in the execution of the next command.
 
 # Parsing
-Below is snippet of the `dump` commandlet showing how it parses it's two arguments. The first is the address which to dump and the second is the length. Note that the first argument is also used as the return value for this commandlet. Note also that the second argument is also converted from a `UInt64` to a `number` type, since this is what is reqired by the `hexdump` function called by `this.dump`. This is used in many commands where the parameter is likely to be a small number and therefore loss of precision is not a concern.
+Below is snippet of the `dump` commandlet showing how it parses it's three arguments. The first is the address which to dump and the second is the length, and the fourth the width. Note that the first argument is also used as the return value for this commandlet. Note also that the second argument is also converted from a `UInt64` to a `number` type, since this is what is reqired by the `hexdump` function called by `this.dump`. This is used in many commands where the parameter is likely to be a small number and therefore loss of precision is not a concern.
 ```js
-  private runWithLength(tokens: Token[]): Var | null {
-    if (tokens.length !== 2) return null;
-
-    const [a0, a1] = tokens;
-    const [t0, t1] = [a0 as Token, a1 as Token];
-    const [v0, v1] = [t0.toVar(), t1.toVar()];
-
-    if (v0 === null) return null;
-    if (v1 === null) return null;
+  public runSync(tokens: Token[]): Var {
+    const vars = this.transformOptional(
+      tokens,
+      [this.parseVar],
+      [this.parseVar, this.parseWidth],
+    );
+    if (vars === null) return this.usage();
+    const [[v0], [v1, v2]] = vars as [[Var], [Var | null, number | null]];
 
     const address = v0.toPointer();
-    const length = v1.toU64().toNumber();
-    this.dump(address, length);
+    const count = v1 === null ? DEFAULT_COUNT : v1.toU64().toNumber();
+    const width = v2 === null ? 1 : v2;
+    this.dump(address, count, width);
     return v0;
   }
 
-  public run(tokens: Token[]): Var {
-    const retWithLength = this.runWithLength(tokens);
-    if (retWithLength !== null) return retWithLength;
-
-    ...
-
-    return this.usage();
+  private dump(address: NativePointer, count: number, width: number = 1) {
+        ...
   }
 ```
 # Scripts

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "frida-cshell",
-  "version": "1.3.2",
+  "version": "1.3.3",
   "description": "Frida's CShell",
   "scripts": {
     "prepare": "npm run build && npm run version && npm run package && npm run copy",

package.json

@@ -38,7 +38,6 @@ export class Bp {
 
   private _hits: number;
   private _addr: Var | null;
-  private _literal: string | null;
   private _length: number;
   private _depth: number;
 
@@ -52,15 +51,13 @@ export class Bp {
     idx: number,
     hits: number,
     addr: Var | null,
-    literal: string | null,
     length: number = 0,
     depth: number = 0,
   ) {
     this._type = type;
     this._idx = idx;
     this._hits = hits;
     this._addr = addr;
-    this._literal = literal;
     this._length = length;
     this._depth = depth;
     this._listener = null;
@@ -196,7 +193,7 @@ export class Bp {
     Output.write(`${Output.yellow('|')} Start Trace `);
     Output.write(`${Output.green(`#${this._idx}`)} `);
     Output.write(`[${this._type}] `);
-    Output.write(`${Output.yellow(this._literal ?? '')} `);
+    Output.write(`${Output.yellow(this.literal)} `);
     Output.write(`@ $pc=${Output.blue(Format.toHexString(ctx.pc))} `);
     Output.write(`$tid=${threadId}, depth=${this._depth}`);
     Output.writeln();
@@ -218,7 +215,7 @@ export class Bp {
       Output.write(`${Output.yellow('|')} Stop Trace `);
       Output.write(`${Output.green(`#${this._idx}`)} `);
       Output.write(`[${this._type}] `);
-      Output.write(`${Output.yellow(this._literal ?? '')} `);
+      Output.write(`${Output.yellow(this.literal)} `);
       Output.write(`@ $pc=${Output.blue(Format.toHexString(ctx.pc))} `);
       Output.write(`$tid=${threadId}`);
       Output.writeln();
@@ -244,7 +241,7 @@ export class Bp {
     Output.write(`${Output.yellow('|')} Break `);
     Output.write(`${Output.green(`#${this._idx}`)} `);
     Output.write(`[${this._type}] `);
-    Output.write(`${Output.yellow(this._literal ?? '')} `);
+    Output.write(`${Output.yellow(this.literal)} `);
     Output.write(`@ $pc=${Output.blue(Format.toHexString(ctx.pc))} `);
     Output.write(`$tid=${threadId}`);
     Output.writeln();
@@ -330,7 +327,7 @@ export class Bp {
     Output.write(`${Output.yellow('|')} Break `);
     Output.write(`${Output.green(`#${this._idx}`)} `);
     Output.write(`[${this._type}] `);
-    Output.write(`${Output.yellow(this._literal ?? '')} `);
+    Output.write(`${Output.yellow(this.literal)} `);
     Output.write(`@ $pc=${Output.blue(Format.toHexString(details.from))} `);
     Output.write(`$addr=${Output.blue(Format.toHexString(details.address))}`);
     Output.writeln();
@@ -364,7 +361,7 @@ export class Bp {
   public toString(short: boolean = false): string {
     const idxString = Output.green(`#${this._idx.toString()}.`.padEnd(4, ' '));
     const typeString = `[${this._type.toString()}]`;
-    const literalString = Output.yellow(this._literal ?? '');
+    const literalString = Output.yellow(this.literal);
     const addString = `@ $pc=${Output.blue(this.addrString)}`;
     const hitsString = `[hits:${this.hitsString}]`;
     const lengthString = this.lengthString;
@@ -416,6 +413,10 @@ export class Bp {
     return this._addr;
   }
 
+  public get literal(): string {
+    return this._addr?.getLiteral() ?? '';
+  }
+
   public get length(): number | null {
     return this._length;
   }
@@ -433,11 +434,6 @@ export class Bp {
     this._addr = addr;
   }
 
-  public set literal(literal: string | null) {
-    if (literal === null) return;
-    this._literal = literal;
-  }
-
   public set length(length: number | null) {
     if (length === null) return;
     this._length = length;

src/breakpoints/bp.ts

@@ -12,7 +12,6 @@ export class Bps {
     type: BpType,
     hits: number = -1,
     addr: Var | null = null,
-    literal: string | null = null,
     length: number = 0,
     depth: number = 0,
   ): Bp {
@@ -23,7 +22,7 @@ export class Bps {
       this.checkOverlaps(type, addr.toPointer(), length);
     }
 
-    const bp = new Bp(type, idx, hits, addr, literal, length, depth);
+    const bp = new Bp(type, idx, hits, addr, length, depth);
     this.byIndex.set(key, bp);
     this.last = bp;
     this.lines = [];
@@ -70,7 +69,6 @@ export class Bps {
     idx: number,
     hits: number,
     addr: Var | null = null,
-    literal: string | null = null,
     length: number = 0,
     depth: number = 0,
   ): Bp {
@@ -88,7 +86,6 @@ export class Bps {
     bp.disable();
     bp.hits = hits;
     bp.address = addr;
-    bp.literal = literal;
     bp.length = length;
     bp.depth = depth;
     this.last = bp;