From bfcdc5538d1b2095904362aebbcb0c35c0679735 Mon Sep 17 00:00:00 2001
From: bQUARKz <bquarkz@gmail.com>
Date: Tue, 10 Feb 2026 08:49:22 +0000
Subject: [PATCH] pr 06

---
 .../prometeu-compiler/src/building/linker.rs  | 85 ++++++++++++++++---
 1 file changed, 75 insertions(+), 10 deletions(-)

diff --git a/crates/prometeu-compiler/src/building/linker.rs b/crates/prometeu-compiler/src/building/linker.rs
index f75fa50e..cd79a06e 100644
--- a/crates/prometeu-compiler/src/building/linker.rs
+++ b/crates/prometeu-compiler/src/building/linker.rs
@@ -7,7 +7,6 @@ use prometeu_bytecode::{ConstantPoolEntry, DebugInfo};
 use std::collections::HashMap;
 use prometeu_abi::virtual_machine::{ProgramImage, Value};
 use prometeu_analysis::ids::ProjectId;
-use prometeu_bytecode::readwrite::{read_u32_le, write_u32_le};
 
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum LinkError {
@@ -210,7 +209,7 @@ impl Linker {
                             let next_pc = instr.next_pc;
                             let imm_start = instr.pc + 2; // start of immediate payload
                             let imm_u32_opt = match opcode {
-                                OpCode::PushConst | OpCode::Call | OpCode::Jmp | OpCode::JmpIfFalse | OpCode::JmpIfTrue => {
+                                OpCode::PushConst | OpCode::Call => {
                                     match instr.imm_u32() {
                                         Ok(v) => Some(v),
                                         Err(_) => None,
@@ -255,15 +254,9 @@ impl Linker {
                             patch_u32_at(&mut combined_code, imm_start, &|_| global_func_idx);
                         }
                     }
-                    // Branches are strictly function-relative. Do NOT relocate.
+                    // Branches are strictly function-relative. Do NOT relocate or inspect immediates.
                     // The emitter encodes `target_rel = label - func_start` and the verifier enforces it.
-                    OpCode::Jmp | OpCode::JmpIfFalse | OpCode::JmpIfTrue => {
-                        let _ = imm_u32_opt.ok_or_else(|| LinkError::IncompatibleSymbolSignature(format!(
-                            "Invalid branch immediate at pc {}",
-                            pc - code_offset
-                        )))?;
-                        // Intentionally no patch here.
-                    }
+                    OpCode::Jmp | OpCode::JmpIfFalse | OpCode::JmpIfTrue => { /* no-op */ }
                     _ => {}
                 }
 
@@ -640,4 +633,76 @@ mod tests {
         let cjmp_patched = u32::from_le_bytes(result.rom[cjmp_imm_off..cjmp_imm_off+4].try_into().unwrap());
         assert_eq!(cjmp_patched, 0);
     }
+
+    #[test]
+    fn test_jump_link_order_invariance() {
+        // Same setup as previous test, but link order is [m2, m1]
+        let key1 = ProjectKey { name: "m1".into(), version: "1.0.0".into() };
+        let id1 = ProjectId(0);
+        let step1 = BuildStep { project_id: id1, project_key: key1.clone(), project_dir: "".into(), target: BuildTarget::Main, sources: vec![], deps: BTreeMap::new() };
+
+        let mut code1 = Vec::new();
+        code1.extend_from_slice(&(OpCode::Add as u16).to_le_bytes());
+        code1.extend_from_slice(&(OpCode::Ret as u16).to_le_bytes());
+        let m1 = CompiledModule {
+            project_id: id1,
+            project_key: key1.clone(),
+            target: BuildTarget::Main,
+            exports: BTreeMap::new(),
+            imports: vec![],
+            const_pool: vec![],
+            code: code1.clone(),
+            function_metas: vec![FunctionMeta { code_offset: 0, code_len: code1.len() as u32, ..Default::default() }],
+            debug_info: None,
+            symbols: vec![],
+        };
+
+        let key2 = ProjectKey { name: "m2".into(), version: "1.0.0".into() };
+        let id2 = ProjectId(1);
+        let step2 = BuildStep { project_id: id2, project_key: key2.clone(), project_dir: "".into(), target: BuildTarget::Main, sources: vec![], deps: BTreeMap::new() };
+
+        let mut code2 = Vec::new();
+        let jmp_pc = code2.len() as u32; // where opcode will be placed
+        code2.extend_from_slice(&(OpCode::Jmp as u16).to_le_bytes());
+        code2.extend_from_slice(&0u32.to_le_bytes());
+
+        code2.extend_from_slice(&(OpCode::PushBool as u16).to_le_bytes());
+        code2.push(1u8);
+        let cjmp_pc = code2.len() as u32;
+        code2.extend_from_slice(&(OpCode::JmpIfTrue as u16).to_le_bytes());
+        code2.extend_from_slice(&0u32.to_le_bytes());
+
+        code2.extend_from_slice(&(OpCode::Halt as u16).to_le_bytes());
+
+        let m2 = CompiledModule {
+            project_id: id2,
+            project_key: key2.clone(),
+            target: BuildTarget::Main,
+            exports: BTreeMap::new(),
+            imports: vec![],
+            const_pool: vec![],
+            code: code2.clone(),
+            function_metas: vec![FunctionMeta { code_offset: 0, code_len: code2.len() as u32, ..Default::default() }],
+            debug_info: None,
+            symbols: vec![],
+        };
+
+        // Link with order [m2, m1]
+        let result = Linker::link(vec![m2, m1], vec![step2, step1]).unwrap();
+
+        // Module 2 is now at offset 0
+        let module2_offset = 0usize;
+
+        // Verify that the JMP immediate remains function-relative (0), no relocation applied
+        let jmp_abs_pc = module2_offset + jmp_pc as usize;
+        let jmp_imm_off = jmp_abs_pc + 2; // skip opcode
+        let jmp_patched = u32::from_le_bytes(result.rom[jmp_imm_off..jmp_imm_off+4].try_into().unwrap());
+        assert_eq!(jmp_patched, 0);
+
+        // Verify that the conditional JMP immediate also remains function-relative (0)
+        let cjmp_abs_pc = module2_offset + cjmp_pc as usize;
+        let cjmp_imm_off = cjmp_abs_pc + 2;
+        let cjmp_patched = u32::from_le_bytes(result.rom[cjmp_imm_off..cjmp_imm_off+4].try_into().unwrap());
+        assert_eq!(cjmp_patched, 0);
+    }
 }