Add `-obfuscate-source-code-locations`

1 files changed, 37 insertions, 4 deletions

diff --git a/src/llvm_backend_const.cpp b/src/llvm_backend_const.cpp
index 7584df3ee..2291f24ac 100644
--- a/src/llvm_backend_const.cpp
+++ b/src/llvm_backend_const.cpp
@@ -287,11 +287,44 @@ gb_internal lbValue lb_expr_untyped_const_to_typed(lbModule *m, Ast *expr, Type
 	return lb_const_value(m, t, tv.value);
 }
 
-gb_internal lbValue lb_const_source_code_location_const(lbModule *m, String const &procedure, TokenPos const &pos) {
+gb_internal String lb_obfuscate_string(String const &s, char const *prefix) {
+	if (s.len == 0) {
+		return {};
+	}
+	GB_ASSERT(prefix != nullptr);
+	u64 hash = gb_fnv64a(s.text, s.len);
+	gbString res = gb_string_make(temporary_allocator(), prefix);
+	res = gb_string_append_fmt(res, "x%llx", cast(long long unsigned)hash);
+	return make_string_c(res);
+}
+
+gb_internal i32 lb_obfuscate_i32(i32 i) {
+	i32 x = cast(i32)gb_fnv64a(&i, sizeof(i));
+	if (x < 0) {
+		x = 1-x;
+	}
+	return cast(i32)x;
+}
+
+gb_internal lbValue lb_const_source_code_location_const(lbModule *m, String const &procedure_, TokenPos const &pos) {
+	String file = get_file_path_string(pos.file_id);
+	String procedure = procedure_;
+
+	i32 line   = pos.line;
+	i32 column = pos.column;
+
+	if (build_context.obfuscate_source_code_locations) {
+		file = lb_obfuscate_string(file, "F");
+		procedure = lb_obfuscate_string(procedure, "P");
+
+		line   = lb_obfuscate_i32(line);
+		column = lb_obfuscate_i32(column);
+	}
+
 	LLVMValueRef fields[4] = {};
-	fields[0]/*file*/      = lb_find_or_add_entity_string(m, get_file_path_string(pos.file_id)).value;
-	fields[1]/*line*/      = lb_const_int(m, t_i32, pos.line).value;
-	fields[2]/*column*/    = lb_const_int(m, t_i32, pos.column).value;
+	fields[0]/*file*/      = lb_find_or_add_entity_string(m, file).value;
+	fields[1]/*line*/      = lb_const_int(m, t_i32, line).value;
+	fields[2]/*column*/    = lb_const_int(m, t_i32, column).value;
 	fields[3]/*procedure*/ = lb_find_or_add_entity_string(m, procedure).value;
 
 	lbValue res = {};