Span trace utilities and runner source hint

src/mir/builder.rs

@@ -9,12 +9,12 @@ use super::{
     BasicBlock, BasicBlockId, BasicBlockIdGenerator, CompareOp, ConstValue, Effect, EffectMask,
     FunctionSignature, MirFunction, MirInstruction, MirModule, MirType, ValueId, ValueIdGenerator,
 };
-use crate::ast::{ASTNode, LiteralValue};
+use crate::ast::{ASTNode, LiteralValue, Span};
 use crate::mir::builder::builder_calls::CallTarget;
 use crate::mir::region::function_slot_registry::FunctionSlotRegistry;
 use crate::mir::region::RegionId;
-use std::collections::{BTreeMap, HashMap};
 use std::collections::HashSet;
+use std::collections::{BTreeMap, HashMap};
 mod builder_calls;
 mod call_resolution; // ChatGPT5 Pro: Type-safe call resolution utilities
 mod calls; // Call system modules (refactored from builder_calls)
@@ -219,6 +219,12 @@ pub struct MirBuilder {
     /// Tracks the depth of build_expression calls to detect infinite loops
     pub(super) recursion_depth: usize,
 
+    /// Current AST span being lowered (used to annotate MIR instructions)
+    pub(super) current_span: Span,
+
+    /// Optional source file hint for metadata/spans
+    pub(super) source_file: Option<String>,
+
     /// Root lowering mode: how to treat top-level Program
     /// - None: not decided yet (lower_root not called)
     /// - Some(true): App mode (static box Main.main is entry)
@@ -243,7 +249,7 @@ impl MirBuilder {
             current_block: None,
             value_gen: ValueIdGenerator::new(),
             block_gen: BasicBlockIdGenerator::new(),
-            compilation_context: None, // 箱理論: デフォルトは従来モード
+            compilation_context: None,     // 箱理論: デフォルトは従来モード
             variable_map: BTreeMap::new(), // Phase 25.1: 決定性確保
             pending_phis: Vec::new(),
             value_origin_newbox: BTreeMap::new(), // Phase 25.1: 決定性確保
@@ -253,7 +259,7 @@ impl MirBuilder {
             field_origin_class: HashMap::new(),
             field_origin_by_box: HashMap::new(),
             value_types: BTreeMap::new(), // Phase 25.1: 決定性確保
-            value_kinds: HashMap::new(), // Phase 26-A: ValueId型安全化
+            value_kinds: HashMap::new(),  // Phase 26-A: ValueId型安全化
             current_slot_registry: None,
             type_registry: type_registry::TypeRegistry::new(),
             plugin_method_sigs,
@@ -290,6 +296,8 @@ impl MirBuilder {
 
             in_unified_boxcall_fallback: false,
             recursion_depth: 0,
+            current_span: Span::unknown(),
+            source_file: None,
             root_is_app_mode: None,
             static_box_singletons: HashMap::new(), // Phase 21.7: methodization support
         }
@@ -347,6 +355,34 @@ impl MirBuilder {
         self.debug_scope_stack.last().cloned()
     }
 
+    /// Hint for downstream metadata: set the logical source file name/path for the next build.
+    pub fn set_source_file_hint<S: Into<String>>(&mut self, source: S) {
+        self.source_file = Some(source.into());
+    }
+
+    /// Clear the source file hint (used when reusing the builder across modules).
+    pub fn clear_source_file_hint(&mut self) {
+        self.source_file = None;
+    }
+
+    /// Resolve current source file hint (builder field or env fallback).
+    fn current_source_file(&self) -> Option<String> {
+        self.source_file
+            .clone()
+            .or_else(|| std::env::var("NYASH_SOURCE_FILE_HINT").ok())
+    }
+
+    /// Create a new MirFunction with source metadata applied.
+    fn new_function_with_metadata(
+        &self,
+        signature: FunctionSignature,
+        entry_block: BasicBlockId,
+    ) -> MirFunction {
+        let mut f = MirFunction::new(signature, entry_block);
+        f.metadata.source_file = self.current_source_file();
+        f
+    }
+
     // ----------------------
     // Compile trace helpers (dev only; env-gated)
     // ----------------------
@@ -739,7 +775,7 @@ impl MirBuilder {
                         }
                     );
                 }
-                block.add_instruction(instruction);
+                block.add_instruction_with_span(instruction, self.current_span);
                 // Drop the mutable borrow of `block` before updating other blocks
             }
             // Update predecessor sets for branch/jump immediately so that