From 915ccb9cbac4b541efc83e698827c76409954765 Mon Sep 17 00:00:00 2001
From: romanornr <6548898+romanornr@users.noreply.github.com>
Date: Fri, 8 May 2026 00:34:37 +0200
Subject: [PATCH] fix(c-lsp): cap expression type evaluation steps

---
 internal/cbm/lsp/c_lsp.c | 15 ++++++++++++---
 internal/cbm/lsp/c_lsp.h |  1 +
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/internal/cbm/lsp/c_lsp.c b/internal/cbm/lsp/c_lsp.c
index 2513a7d0..71d4229e 100644
--- a/internal/cbm/lsp/c_lsp.c
+++ b/internal/cbm/lsp/c_lsp.c
@@ -1204,11 +1204,20 @@ static const char* type_to_qn(const CBMType* t) {
 
 static const CBMType* c_eval_expr_type_inner(CLSPContext* ctx, TSNode node);
 
+#define C_EVAL_DEPTH_LIMIT 256
+#define C_EVAL_MAX_STEPS_PER_FILE 10000
+
 const CBMType* c_eval_expr_type(CLSPContext* ctx, TSNode node) {
     if (ts_node_is_null(node)) return cbm_type_unknown();
-    /* Guard against unbounded recursion on deeply nested C++ templates.
-     * Prevents stack overflow and NULL-deref from unusual AST shapes. */
-    if (ctx->eval_depth > 256) {
+    /* Expression type evaluation is best-effort. Some recovery-mode C++ ASTs
+     * can repeatedly drive member/type lookup without increasing recursion
+     * depth. Keep a generous per-file work budget so pathological expressions
+     * degrade to unknown instead of hanging repository indexing. */
+    if (ctx->eval_depth > C_EVAL_DEPTH_LIMIT ||
+        ctx->eval_steps++ > C_EVAL_MAX_STEPS_PER_FILE) {
+        if (ctx->debug && ctx->eval_steps == C_EVAL_MAX_STEPS_PER_FILE + 2) {
+            fprintf(stderr, "  [clsp] expression eval step budget exhausted; returning unknown\n");
+        }
         return cbm_type_unknown();
     }
     ctx->eval_depth++;
diff --git a/internal/cbm/lsp/c_lsp.h b/internal/cbm/lsp/c_lsp.h
index 51f10b3e..00832191 100644
--- a/internal/cbm/lsp/c_lsp.h
+++ b/internal/cbm/lsp/c_lsp.h
@@ -75,6 +75,7 @@ typedef struct {
     bool in_template;       // currently inside template declaration
     bool debug;
     int eval_depth;         // recursion depth for c_eval_expr_type (crash guard)
+    int eval_steps;         // total expression eval calls for current file (hang guard)
 } CLSPContext;
 
 // --- API ---