auto temp = get_arg_value<arg_type>(index); \
if (!temp.has_value()) { \
section.has_conv = false; \
+ } else { \
+ dst = cpp::bit_cast<int_type_of_v<arg_type>>(temp.value()); \
} \
- dst = cpp::bit_cast<int_type_of_v<arg_type>>(temp.value()); \
}
#else
#define WRITE_ARG_VAL_SIMPLEST(dst, arg_type, _) \
section.conv_name = str[cur_pos];
switch (str[cur_pos]) {
case ('%'):
+ // Regardless of options, a % conversion is always safe. The standard says
+ // that "The complete conversion specification shall be %%" but it also
+ // says that "If a conversion specification is invalid, the behavior is
+ // undefined." Based on that we define that any conversion specification
+ // ending in '%' shall display as '%' regardless of any valid or invalid
+ // options.
+ section.has_conv = true;
break;
case ('c'):
WRITE_ARG_VAL_SIMPLEST(section.conv_val_raw, int, conv_index);
EXPECT_PFORMAT_EQ(expected1, format_arr[1]);
}
+TEST(LlvmLibcPrintfParserTest, DoublePercentIsAllowedInvalidIndex) {
+ __llvm_libc::printf_core::FormatSection format_arr[10];
+
+ // Normally this conversion specifier would be raw (due to having a width
+ // defined as an invalid argument) but since it's a % conversion it's allowed
+ // by this specific parser. Any % conversion that is not just "%%" is
+ // undefined, so this is implementation-specific behavior.
+ // The goal is to be consistent. A conversion specifier of "%L%" is also
+ // undefined, but is traditionally displayed as just "%". "%2%" is also
+ // displayed as "%", even though if the width was respected it should be " %".
+ // Finally, "%*%" traditionally is displayed as "%" but also traditionally
+ // consumes an argument, since the * consumes an integer. Therefore, having
+ // "%*2$%" display as "%" is consistent with other printf behavior.
+ const char *str = "%*2$%";
+
+ evaluate(format_arr, str, 1, 2);
+
+ __llvm_libc::printf_core::FormatSection expected0;
+ expected0.has_conv = true;
+
+ expected0.raw_string = str;
+ expected0.conv_name = '%';
+ EXPECT_PFORMAT_EQ(expected0, format_arr[0]);
+}
+
#endif // LIBC_COPT_PRINTF_DISABLE_INDEX_MODE