enum_parser: support digit separators in numeric literals

commit_hash:9791d25e9ea02f73329f9755f7c70f335c612121

1 files changed, 34 insertions, 0 deletions

diff --git a/library/cpp/cppparser/parser.cpp b/library/cpp/cppparser/parser.cpp
index 3bd968b459..70fb6a8735 100644
--- a/library/cpp/cppparser/parser.cpp
+++ b/library/cpp/cppparser/parser.cpp
@@ -1,4 +1,5 @@
 #include <util/generic/hash.h>
+#include <util/string/ascii.h>
 #include <util/string/cast.h>
 #include <util/generic/hash_set.h>
 #include <util/generic/yexception.h>
@@ -127,6 +128,10 @@ private:
                             break;
 
                         case '\'':
+                            if (QuoteCharIsADigitSeparator()) {
+                                Text_.Data += ch;
+                                break;
+                            }
                             Action(ch);
                             State_ = Character;
 
@@ -356,6 +361,35 @@ private:
         }
     }
 
+    // digit separator in integral literal (ex. 73'709'550'592)
+    bool QuoteCharIsADigitSeparator() const {
+        const TStringBuf data = Text_.Data;
+        if (data.empty()) {
+            return false;
+        }
+        if (!IsAsciiHex(data.back())) {
+            return false;
+        }
+        // check for char literal prefix (ex. `u8'$'`)
+        static constexpr TStringBuf literalPrefixes[] {
+            "u8",
+            "u",
+            "U",
+            "L",
+        };
+        for (const TStringBuf& literalPrefix : literalPrefixes) {
+            if (TStringBuf prev; data.BeforeSuffix(literalPrefix, prev)) {
+                if (!prev.empty() && (IsAsciiAlnum(prev.back()) || prev.back() == '_' || prev.back() == '$')) {
+                    // some macro name ends with an `u8` sequence
+                    continue;
+                }
+                // it is a prefixed character literal
+                return false;
+            }
+        }
+        return true;
+    }
+
     inline void Action(char ch) {
         Action();
         Text_.Data += ch;