demumble swift symbols as well

demumble.cc

@@ -5,6 +5,7 @@
 #include <algorithm>
 
 #include "llvm/Demangle/Demangle.h"
+#include "swift/Demangling/Demangle.h"
 
 const char kDemumbleVersion[] = "1.2.3.git";
 
@@ -33,6 +34,14 @@ static void print_demangled(const char* format, std::string_view s,
   } else if (char* ms = llvm::microsoftDemangle(s, n_used, NULL)) {
     printf(format, ms, (int)s.size(), s.data());
     free(ms);
+  } else if (swift::Demangle::isSwiftSymbol(s)) {
+    swift::Demangle::DemangleOptions options;
+    options.SynthesizeSugarOnTypes = true;
+    std::string swift = swift::Demangle::demangleSymbolAsString(s, options);
+    if (swift == s)
+      printf("%.*s", (int)s.size(), s.data()); // Not a mangled name
+    else
+      printf(format, swift.c_str(), (int)s.size(), s.data());
   } else {
     printf("%.*s", (int)s.size(), s.data());
   }
@@ -49,6 +58,12 @@ static bool is_mangle_char_rust(char c) {
          (c >= '0' && c <= '9') || c == '_';
 }
 
+static bool is_mangle_char_swift(char c) {
+  // https://github.com/swiftlang/swift/blob/main/docs/ABI/Mangling.rst
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
+         (c >= '0' && c <= '9') || c == '_' || c == '$';
+}
+
 static bool is_mangle_char_win(char c) {
   return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
          (c >= '0' && c <= '9') || strchr("?_@$", c);
@@ -68,6 +83,18 @@ static bool is_plausible_rust_prefix(char* s) {
   return s[0] == '_' && s[1] == 'R';
 }
 
+static bool is_plausible_swift_prefix(char* s) {
+  // https://github.com/swiftlang/swift/blob/main/docs/ABI/Mangling.rst
+  // But also swift/test/Demangle/Inputs/manglings.txt, which has
+  // _Tt, _TF etc as prefix.
+
+  // FIXME: This is missing prefix `@__swiftmacro_`.
+  return
+    (s[0] == '$' && s[1] == 's') ||
+    (s[0] == '_' && s[1] == 'T') ||
+    (s[0] == '$' && s[1] == 'S');
+}
+
 static char buf[8192];
 int main(int argc, char* argv[]) {
   enum { kPrintAll, kPrintMatching } print_mode = kPrintAll;
@@ -119,7 +146,7 @@ int main(int argc, char* argv[]) {
       char* end = cur + strlen(cur);
 
       while (cur != end) {
-        size_t offset_to_possible_symbol = strcspn(cur, "_?");
+        size_t offset_to_possible_symbol = strcspn(cur, "_?$");
         if (print_mode == kPrintAll)
           printf("%.*s", static_cast<int>(offset_to_possible_symbol), cur);
         else if (need_separator)
@@ -139,6 +166,9 @@ int main(int argc, char* argv[]) {
         else if (is_plausible_rust_prefix(cur))
           while (cur + n_sym != end && is_mangle_char_rust(cur[n_sym]))
             ++n_sym;
+        else if (is_plausible_swift_prefix(cur))
+          while (cur + n_sym != end && is_mangle_char_swift(cur[n_sym]))
+            ++n_sym;
         else {
           if (print_mode == kPrintAll)
             printf("_");

demumble_test.py

@@ -9,6 +9,10 @@
      'std::mem::align_of::<f64>\nmylib::foo::bar\n'),
     ('demumble < _RINvNtC3std3mem8align_ofdE _RNvNvC5mylib3foo3bar',
      'std::mem::align_of::<f64>\nmylib::foo::bar\n'),
+    ('demumble _TtP3foo3bar_', 'foo.bar\n'),
+    ('demumble < _TtP3foo3bar_', 'foo.bar\n'),
+    ('demumble $sSS5countSivg', 'Swift.String.count.getter : Swift.Int\n'),
+    ('demumble < $sSS5countSivg', 'Swift.String.count.getter : Swift.Int\n'),
     ('demumble ?Fxi@@YAHP6AHH@Z@Z', 'int __cdecl Fxi(int (__cdecl *)(int))\n'),
     ('demumble ??0S@@QEAA@$$QEAU0@@Z', 'public: __cdecl S::S(struct S &&)\n'),
     ('demumble ??_C@_02PCEFGMJL@hi?$AA@', '"hi"\n'),