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Fix Option<String> pattern match double-dereference in C codegen

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LuxString is typedef char* but the codegen treated it as a struct type,
generating *(LuxString*)(field0) instead of (LuxString)(field0). This
caused a heap-buffer-overflow on any Option<String> pattern match since
it read the string contents as a memory address.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Brandon Lucas
2026-02-22 23:59:47 -05:00
parent 92d443e475
commit 81e58cf3d5
1 changed files with 4 additions and 3 deletions
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7
src/codegen/c_backend.rs
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@@ -5316,11 +5316,12 @@ impl CBackend {
if Self::is_primitive_c_type(&actual_type) { if Self::is_primitive_c_type(&actual_type) {
// For primitive types stored as boxed void*, dereference // For primitive types stored as boxed void*, dereference
self.writeln(&format!("{} {} = *({}*)({});", actual_type, var_name, actual_type, c_expr)); self.writeln(&format!("{} {} = *({}*)({});", actual_type, var_name, actual_type, c_expr));
} else if !actual_type.ends_with('*') && actual_type != "void" { } else if actual_type == "LuxString" || actual_type.ends_with('*') || actual_type == "void" {
// Pointer types (including LuxString which is typedef char*): simple cast
self.writeln(&format!("{} {} = ({})({});", actual_type, var_name, actual_type, c_expr));
} else {
// Struct types: cast to pointer and dereference // Struct types: cast to pointer and dereference
self.writeln(&format!("{} {} = *({}*)({});", actual_type, var_name, actual_type, c_expr)); self.writeln(&format!("{} {} = *({}*)({});", actual_type, var_name, actual_type, c_expr));
} else {
self.writeln(&format!("{} {} = ({})({});", actual_type, var_name, actual_type, c_expr));
} }
self.var_types.insert(var_name.clone(), actual_type); self.var_types.insert(var_name.clone(), actual_type);
} else if actual_type.ends_with('*') && actual_type != "void*" { } else if actual_type.ends_with('*') && actual_type != "void*" {