Accept the j format specifier and escape braces in printf

cpp2rust/converter/models/converter_refcount.cpp

@@ -1137,6 +1137,14 @@ void ConverterRefCount::ConvertDeclRefValue(clang::Expr *expr,
 
 static std::vector<const char *> printf2fmt(std::string &format) {
   std::vector<const char *> types;
+  std::string escaped;
+  for (char c : format) {
+    escaped += c;
+    if (c == '{' || c == '}') {
+      escaped += c;
+    }
+  }
+  format = std::move(escaped);
   size_t pos = 0;
   while ((pos = format.find('%', pos)) != std::string::npos) {
     if (pos + 1 >= format.size())
@@ -1181,6 +1189,7 @@ static std::vector<const char *> printf2fmt(std::string &format) {
         continue;
       }
       break;
+    case 'j':
     case 'z':
       if (pos + 2 < format.size() &&
           (format[pos + 2] == 'd' || format[pos + 2] == 'u')) {

tests/unit/out/refcount/printfs.rs

@@ -53,6 +53,7 @@ fn main_0() -> i32 {
         "{}",
         (Ptr::<Vec<i8>>::decay(&({ fn2_1(s.as_pointer(),) })) as Ptr<i8>)
     );
+    println!("{{}} {} {}", 5_u64, (-6_i32 as i64));
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/printfs.rs

@@ -56,6 +56,11 @@ unsafe fn main_0() -> i32 {
         c"%s\n".as_ptr() as *const i8,
         (*(unsafe { fn2_1(&s) })).as_ptr(),
     );
+    printf(
+        c"{} %ju %jd\n".as_ptr() as *const i8,
+        5_u64,
+        (-6_i32 as i64),
+    );
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}

tests/unit/printfs.cpp

@@ -1,4 +1,5 @@
 #include <cassert>
+#include <cstdint>
 #include <cstdio>
 #include <string>
 
@@ -18,5 +19,6 @@ int main() {
   printf("%s\n", s.data());
   printf("%s\n", fn("foo").c_str());
   printf("%s\n", fn2(s).c_str());
+  printf("{} %ju %jd\n", (uintmax_t)5, (intmax_t)-6);
   return 0;
 }