feat(selfhost): multi-file #line paths from Decl.sourceFile

Stamp each merged .bux path onto decls, propagate to HirFunc, and emit
#line N \"path\" per function without requiring BUX_DEBUG_FILE.

- Decl.sourceFile + Cli_StampSourceFile on merge/project parse
- HirFunc.sourceFile; CBE switches currentFile per function
- Stdlib and multi-file user packages get distinct paths automatically

docs/BuildAndTest.md

@@ -148,13 +148,14 @@ make bench-nexus     # wrk throughput vs apps/nexus /api/health
 ```bash
 ./buxc build              # -O0 -g, #line → .bux (gdb-friendly; bootstrap)
 ./buxc build --release    # -O2 -DNDEBUG, no #line / -g
-# Selfhost (buxc2): same --release / default -O0 -g; #line via HIR line numbers
+# Selfhost (buxc2): default -O0 -g; multi-file #line from Decl.sourceFile
-export BUX_DEBUG_FILE=src/Main.bux   # path embedded in #line (selfhost)
+# (stdlib + each src/*.bux get their own path — no env needed)
 export BUX_NO_LINE=1                 # disable selfhost #line maps
-export BUX_CFLAGS="-fno-omit-frame-pointer"   # optional extra cc flags
+export BUX_DEBUG_FILE=/abs/path.bux  # optional: force all #line to one path
+export BUX_CFLAGS="-fno-omit-frame-pointer"
 gdb --args ./build/myapp
 #   (gdb) break Main
-#   (gdb) list            # Bux source via #line
+#   (gdb) list            # Bux source via #line (correct file per function)
 ```
 
 

docs/QUALITY_PLAN.md

@@ -1,7 +1,7 @@
 # Bux — План към „добър“ език (v0.5 → v1.0)
 
 > **Дата:** 2026-07-19  
-> **Текущо:** v0.5.x — field-move, selfhost #line, Nexus KA, **LSP 0.8 call hierarchy**  
+> **Текущо:** v0.5.x — field-move, **multi-file #line**, Nexus KA, LSP 0.8 call hierarchy  
 > **Цел:** Език, с който се пишат реални проекти комфортно, безопасно (по избор) и с надежден toolchain.
 
 ---
@@ -78,7 +78,7 @@
 
 | # | Задача | Защо | Статус |
 |---|--------|------|--------|
-| D.1 | LSP: hover, go-to-def, diagnostics | IDE = adoption | ✅ v0.7.0: + **field/variant rename** + workspace/symbol |
+| D.1 | LSP: hover, go-to-def, diagnostics | IDE = adoption | ✅ v0.8.0: + **call hierarchy** + deeper rename + workspace/symbol |
 | D.2 | `bux fmt` стабилен + CI check | Единен style | ✅ full-tree format + `make fmt-check` enforce |
 | D.3 | `bux test` с `--filter`, exit codes, summary table | CI-friendly | ✅ `--filter` / summary / exit 0\|1 |
 | D.4 | `bux doc` от `///` comments | Самодокументиращ се stdlib | ✅ bootstrap+selfhost + `make docs` |
@@ -642,9 +642,23 @@ A (stdlib ergonomics)  →  B (compiler holes)  →  C (ownership depth)
 
 ---
 
+## Сесия 40 (LSP 0.8 call hierarchy)
+
+1. **Providers:**
+   - `textDocument/prepareCallHierarchy`
+   - `callHierarchy/incomingCalls` — who calls F
+   - `callHierarchy/outgoingCalls` — what F calls
+2. **Graph:** textual scan of known `func` symbols + `Name(` call sites;
+   enclosing function via nearest prior `func` decl line
+3. Skips the declaration itself; workspace disk scan for other `.bux` files
+4. Smoke: `tools/smoke_lsp_call_hierarchy.sh` (Add ← Compute; Compute → Add/Mul)
+5. Version **bux-lsp 0.8.0**; `make test-lsp`
+
+---
+
 ## Следващи стъпки
 
-1. LSP call hierarchy (optional)
+1. Selfhost multi-file `#line` paths without BUX_DEBUG_FILE
-2. Selfhost multi-file `#line` paths without BUX_DEBUG_FILE
+2. Wire selfhost smoke for move_field into CI
-3. Wire selfhost smoke for move_field into CI
+3. Method call hierarchy (receiver methods / interface dispatch)
 4. Rename of method receivers / qualified module paths (edge cases)

src/ast.bux

@@ -299,6 +299,8 @@ module Ast {
         isDrop: int,             // @[Drop] attribute (0/1)
         isRelease: int,          // @[Release] attribute (0/1)
         isConst: int,            // const func (0/1)
+        // Source file path for #line / diagnostics (multi-file projects)
+        sourceFile: String,
         // Names
         strValue: String,        // decl name
         strValue2: String,       // interface name, dll name, module path
@@ -418,6 +420,7 @@ module Ast {
 
     func Ast_MakeDecl(kind: int, line: uint32, col: uint32) -> Decl {
         return Decl { kind: kind, line: line, column: col, isPublic: false,
+            sourceFile: "",
             isAsync: false, isChecked: 0, isDrop: 0, isRelease: 0, isConst: 0,
             strValue: "", strValue2: "",
             typeParam0: "", typeParam1: "", typeParamCount: 0,

src/c_backend.bux

@@ -1407,7 +1407,7 @@ module CBackend {
         cbe.lastDebugLine = 0;
         cbe.emitDebugLines = true;
         cbe.currentFile = "";
-        // Optional: BUX_DEBUG_FILE sets the #line path for gdb (selfhost has no multi-file loc yet)
+        // Optional override for all #line paths (default: per-func Decl.sourceFile)
         let dbgFile: String = bux_getenv("BUX_DEBUG_FILE");
         if dbgFile != null as String && !String_Eq(dbgFile, "") {
             cbe.currentFile = dbgFile;
@@ -1696,6 +1696,17 @@ module CBackend {
                 i = i + 1;
                 continue;
             }
+            // Per-function source path for multi-file #line (overrides BUX_DEBUG_FILE only if set)
+            if !String_Eq(mod.funcs[i].sourceFile, "") {
+                cbe.currentFile = mod.funcs[i].sourceFile;
+            }
+            cbe.lastDebugLine = 0;
+            // #line before the function itself
+            if cbe.emitDebugLines && !String_Eq(cbe.currentFile, "") {
+                StringBuilder_Append(&cbe.sb, "#line 1 \"");
+                StringBuilder_Append(&cbe.sb, cbe.currentFile);
+                StringBuilder_Append(&cbe.sb, "\"\n");
+            }
             CBE_EmitFuncDecl(cbe, &mod.funcs[i]);
             StringBuilder_Append(&cbe.sb, " {\n");
             // Capturing closure thunk: materialize env from fat-func env pointer

src/cli.bux

@@ -611,6 +611,27 @@ func Cli_CollectStdlibImports(mod: *Module, outPaths: *String, maxCount: int, st
     return count;
 }
 
+/// Stamp sourceFile on a decl and nested module items (for multi-file #line).
+func Cli_StampSourceFile(decl: *Decl, path: String) {
+    if decl == null as *Decl { return; }
+    decl.sourceFile = path;
+    if decl.kind == dkModule {
+        var inner: *Decl = decl.childDecl1;
+        while inner != null as *Decl {
+            Cli_StampSourceFile(inner, path);
+            inner = inner.childDecl2;
+        }
+    }
+    // Impl methods
+    if decl.kind == dkImpl {
+        var m: *Decl = decl.childDecl1;
+        while m != null as *Decl {
+            Cli_StampSourceFile(m, path);
+            m = m.childDecl2;
+        }
+    }
+}
+
 func Cli_MergeFileInto(target: *Module, path: String, skipNames: *String, skipCount: int) -> int {
     if !FileExists(path) {
         Print("Error: stdlib file not found: ");
@@ -623,6 +644,12 @@ func Cli_MergeFileInto(target: *Module, path: String, skipNames: *String, skipCo
     if Lexer_DiagCount(lex) > 0 { return 0; }
     let mod: *Module = Parser_Parse(lex.tokens, lex.tokenCount);
     if mod == null as *Module { return 0; }
+    // Tag every decl from this file for #line maps
+    var stamp: *Decl = mod.firstItem;
+    while stamp != null as *Decl {
+        Cli_StampSourceFile(stamp, path);
+        stamp = stamp.childDecl2;
+    }
 
     var added: int = 0;
     var decl: *Decl = mod.firstItem;
@@ -1431,6 +1458,12 @@ func Cli_BuildProject(projectDir: String, targetTriple: String, isRelease: bool)
             PrintLine(path);
             return 1;
         }
+        // Tag decls with this source path for multi-file #line
+        var stampUser: *Decl = mod.firstItem;
+        while stampUser != null as *Decl {
+            Cli_StampSourceFile(stampUser, path);
+            stampUser = stampUser.childDecl2;
+        }
         // Merge declarations from this module into userMerged
         var decl: *Decl = mod.firstItem;
         var fileDeclCount: int = 0;

src/hir.bux

@@ -115,6 +115,8 @@ module Hir {
         envStructName: String;
         envInstanceName: String;
         checkedFunc: bool;
+        // Absolute/relative path for #line maps (multi-file selfhost)
+        sourceFile: String;
     }
 
     // ---------------------------------------------------------------------------

src/hir_lower.bux

@@ -3423,6 +3423,7 @@ module HirLower {
         f.name = decl.strValue;
         f.isPublic = decl.isPublic;
         f.checkedFunc = ctx.checkedFunc;
+        f.sourceFile = decl.sourceFile;
         f.paramCount = decl.paramCount;
         f.param0 = bux_alloc(sizeof(HirParam)) as *HirParam;
         Lcx_LowerParam(f.param0, &decl.param0, ctx);