add support for out-of-order constant declaration

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "customasm"
-version = "0.11.15"
+version = "0.12.0"
 edition = "2021"
 authors = ["hlorenzi <https://hlorenzi.com>"]
 description = "An assembler for custom, user-defined instruction sets!"

src/asm/invocation.rs

@@ -17,6 +17,7 @@ pub enum InvocationKind
     Rule(RuleInvocation),
     Data(DataInvocation),
     Label(LabelInvocation),
+    Constant(ConstantInvocation),
 }
 
 
@@ -57,6 +58,14 @@ pub struct DataInvocation
 pub struct LabelInvocation;
 
 
+#[derive(Debug)]
+pub struct ConstantInvocation
+{
+    pub expr: expr::Expr,
+    pub value_guess: expr::Value,
+}
+
+
 impl Invocation
 {
     pub fn get_rule_invoc(&self) -> &RuleInvocation

src/asm/mod.rs

@@ -28,6 +28,7 @@ pub use self::invocation::RuleInvocationCandidate;
 pub use self::invocation::RuleInvocationArgument;
 pub use self::invocation::DataInvocation;
 pub use self::invocation::LabelInvocation;
+pub use self::invocation::ConstantInvocation;
 pub use self::bank::Bank;
 pub use self::bank::BankData;
 pub use self::symbol::SymbolManager;

src/asm/parser/symbol.rs

@@ -32,7 +32,19 @@ pub fn parse_symbol(
             &ctx,
             &mut expr::EvalContext::new(),
             state.fileserver,
-            true)?;
+            false)?;
+
+        let bankdata = state.asm_state.get_bankdata_mut(state.asm_state.cur_bank);
+        bankdata.push_invocation(asm::Invocation
+        {
+            ctx: ctx.clone(),
+            size_guess: 0,
+            span: span.clone(),
+            kind: asm::InvocationKind::Constant(asm::ConstantInvocation {
+                expr,
+                value_guess: value.clone(),
+            }),
+        });
 
         state.parser.expect_linebreak()?;
         value

src/asm/state.rs

@@ -498,6 +498,26 @@ impl State
 
 					continue;
 				}
+
+				asm::InvocationKind::Constant(ref constant_invoc) =>
+				{
+					let final_value = self.eval_expr(
+						report.clone(),
+						&constant_invoc.expr,
+						&invoc.ctx,
+						&mut expr::EvalContext::new(),
+						fileserver,
+						true)?;
+
+					if final_value != constant_invoc.value_guess
+					{
+						report.error_span(
+							"constant value did not converge after iterations",
+							&invoc.span);
+					}
+
+					continue;
+				}
 			};
 
 			let resolved = match maybe_resolved

tests/symbol_constant_outoforder/err1_unknown_y.asm

@@ -0,0 +1,3 @@
+x = y + y ; error: unknown
+
+#d8 x

tests/symbol_constant_outoforder/err2_unknown_z.asm

@@ -0,0 +1,5 @@
+x = y + y
+y = z + z ; error: unknown
+
+#d8 x
+#d8 y

tests/symbol_constant_outoforder/err3_cyclical.asm

@@ -0,0 +1,6 @@
+x = y + 1 ; error: converge
+y = z + 1 ; error: converge
+z = x + 1
+
+#d8 x
+#d8 y

tests/symbol_constant_outoforder/err4_cascading_instr.asm

@@ -0,0 +1,20 @@
+#ruledef test
+{
+    ld {x} =>
+    {
+        assert(x <= 0x8)
+        0x11 @ x`16
+    }
+
+    ld {x} =>
+    {
+        assert(x > 0x8)
+        0x22 @ x`8
+    }
+}
+
+x = y ; error: converge
+    ld x
+    ld x
+label:
+y = label + 3

tests/symbol_constant_outoforder/err5_cascading_instr.asm

@@ -0,0 +1,20 @@
+#ruledef test
+{
+    ld {x} =>
+    {
+        assert(x <= 0x8)
+        0x11 @ x`16
+    }
+
+    ld {x} =>
+    {
+        assert(x > 0x8)
+        0x22 @ x`8
+    }
+}
+
+    ld x ; error: converge
+    ld x ; error: converge
+x = y
+label:
+y = label + 3

tests/symbol_constant_outoforder/ok1_xy.asm

@@ -0,0 +1,5 @@
+x = y + y
+y = 1
+
+#d8 x ; = 0x02
+#d8 y ; = 0x01

tests/symbol_constant_outoforder/ok2_xyz.asm

@@ -0,0 +1,7 @@
+x = y + y
+y = z + z
+z = 1
+
+#d8 x ; = 0x04
+#d8 y ; = 0x02
+#d8 z ; = 0x01

tests/symbol_constant_outoforder/ok3_cyclical_allzero.asm

@@ -0,0 +1,5 @@
+x = y
+y = x
+
+#d8 x ; = 0x00
+#d8 y ; = 0x00

tests/symbol_constant_outoforder/ok4_cascading_instr.asm

@@ -0,0 +1,24 @@
+#ruledef test
+{
+    ld {x} =>
+    {
+        assert(x <= 0x8)
+        0x11 @ x`16
+    }
+
+    ld {x} =>
+    {
+        assert(x > 0x8)
+        0x22 @ x`8
+    }
+}
+
+x1 = y1 + y1
+ld x1 ; = 0x2210
+ld x1 ; = 0x2210
+y1 = 8
+
+ld x2 ; = 0x110002
+ld x2 ; = 0x110002
+x2 = y2 + y2
+y2 = 1

tests/symbol_constant_outoforder/ok5_cascading_instr.asm

@@ -0,0 +1,20 @@
+#ruledef test
+{
+    ld {x} =>
+    {
+        assert(x <= 0x8)
+        0x11 @ x`16
+    }
+
+    ld {x} =>
+    {
+        assert(x > 0x8)
+        0x22 @ x`8
+    }
+}
+
+x = y
+    ld x ; = 0x110006
+    ld x ; = 0x110006
+y = label
+label: