[PATCH 2/2] tools/nolibc: implement strtol() and friends
From: Thomas Weißschuh
Date: Thu Apr 25 2024 - 12:10:57 EST
The implementation always works on uintmax_t values.
This is inefficient when only 32bit are needed.
However for all functions this only happens for strtol() on 32bit
platforms.
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
tools/include/nolibc/stdlib.h | 109 +++++++++++++++++++++++++++
tools/testing/selftests/nolibc/nolibc-test.c | 59 +++++++++++++++
2 files changed, 168 insertions(+)
diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 5be9d3c7435a..f66870e25389 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -438,6 +438,115 @@ char *u64toa(uint64_t in)
return itoa_buffer;
}
+static __attribute__((unused))
+uintmax_t __strtox(const char *nptr, char **endptr, int base, intmax_t lower_limit, uintmax_t upper_limit)
+{
+ const char signed_ = lower_limit != 0;
+ unsigned char neg = 0, overflow = 0;
+ uintmax_t val = 0, limit, old_val;
+ char c;
+
+ if (base < 0 || base > 35) {
+ SET_ERRNO(EINVAL);
+ goto out;
+ }
+
+ while (isspace(*nptr))
+ nptr++;
+
+ if (*nptr == '+') {
+ nptr++;
+ } else if (*nptr == '-') {
+ neg = 1;
+ nptr++;
+ }
+
+ if (signed_ && neg)
+ limit = -(uintmax_t)lower_limit;
+ else
+ limit = upper_limit;
+
+ if ((base == 0 || base == 16) &&
+ (strncmp(nptr, "0x", 2) == 0 || strncmp(nptr, "0X", 2) == 0)) {
+ base = 16;
+ nptr += 2;
+ } else if (base == 0 && strncmp(nptr, "0", 1) == 0) {
+ base = 8;
+ nptr += 1;
+ } else if (base == 0) {
+ base = 10;
+ }
+
+ while (*nptr) {
+ c = *nptr;
+
+ if (c >= '0' && c <= '9')
+ c -= '0';
+ else if (c >= 'a' && c <= 'z')
+ c = c - 'a' + 10;
+ else if (c >= 'A' && c <= 'Z')
+ c = c - 'A' + 10;
+ else
+ goto out;
+
+ if (c > base)
+ goto out;
+
+ nptr++;
+ old_val = val;
+ val *= base;
+ val += c;
+
+ if (val > limit || val < old_val)
+ overflow = 1;
+ }
+
+out:
+ if (overflow) {
+ SET_ERRNO(ERANGE);
+ val = limit;
+ }
+ if (endptr)
+ *endptr = (char *)nptr;
+ return (neg ? -1 : 1) * val;
+}
+
+static __attribute__((unused))
+long strtol(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, LONG_MIN, LONG_MAX);
+}
+
+static __attribute__((unused))
+unsigned long strtoul(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, 0, ULONG_MAX);
+}
+
+static __attribute__((unused))
+long long strtoll(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, LLONG_MIN, LLONG_MAX);
+}
+
+static __attribute__((unused))
+unsigned long long strtoull(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, 0, ULLONG_MAX);
+}
+
+static __attribute__((unused))
+intmax_t strtoimax(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, INTMAX_MIN, INTMAX_MAX);
+}
+
+static __attribute__((unused))
+uintmax_t strtoumax(const char *nptr, char **endptr, int base)
+{
+ return __strtox(nptr, endptr, base, 0, UINTMAX_MAX);
+}
+
/* make sure to include all global symbols */
#include "nolibc.h"
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index b9c84d42edbe..6161bd57a0c9 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -621,6 +621,51 @@ int expect_str_buf_eq(size_t expr, const char *buf, size_t val, int llen, const
return 0;
}
+#define EXPECT_STRTOX(cond, func, input, base, expected, chars, expected_errno) \
+ do { if (!(cond)) result(llen, SKIPPED); else ret += expect_strtox(llen, func, input, base, expected, chars, expected_errno); } while (0)
+
+static __attribute__((unused))
+int expect_strtox(int llen, void *func, const char *input, int base, intmax_t expected, int expected_chars, int expected_errno)
+{
+ char *endptr;
+ int actual_errno, actual_chars;
+ intmax_t r;
+
+ errno = 0;
+ if (func == strtol) {
+ r = strtol(input, &endptr, base);
+ } else if (func == strtoul) {
+ r = strtoul(input, &endptr, base);
+ } else {
+ result(llen, FAIL);
+ return 1;
+ }
+ actual_errno = errno;
+ actual_chars = endptr - input;
+
+ llen += printf(" %lld = %lld", (long long)expected, (long long)r);
+ if (r != expected) {
+ result(llen, FAIL);
+ return 1;
+ }
+ if (expected_chars == -1) {
+ if (*endptr != '\0') {
+ result(llen, FAIL);
+ return 1;
+ }
+ } else if (expected_chars != actual_chars) {
+ result(llen, FAIL);
+ return 1;
+ }
+ if (actual_errno != expected_errno) {
+ result(llen, FAIL);
+ return 1;
+ }
+
+ result(llen, OK);
+ return 0;
+}
+
/* declare tests based on line numbers. There must be exactly one test per line. */
#define CASE_TEST(name) \
case __LINE__: llen += printf("%d %s", test, #name);
@@ -1143,6 +1188,20 @@ int run_stdlib(int min, int max)
CASE_TEST(limit_ptrdiff_min); EXPECT_EQ(1, PTRDIFF_MIN, sizeof(long) == 8 ? (ptrdiff_t) 0x8000000000000000LL : (ptrdiff_t) 0x80000000); break;
CASE_TEST(limit_ptrdiff_max); EXPECT_EQ(1, PTRDIFF_MAX, sizeof(long) == 8 ? (ptrdiff_t) 0x7fffffffffffffffLL : (ptrdiff_t) 0x7fffffff); break;
CASE_TEST(limit_size_max); EXPECT_EQ(1, SIZE_MAX, sizeof(long) == 8 ? (size_t) 0xffffffffffffffffULL : (size_t) 0xffffffffU); break;
+ CASE_TEST(strtol_simple); EXPECT_STRTOX(1, strtol, "35", 10, 35, -1, 0); break;
+ CASE_TEST(strtol_positive); EXPECT_STRTOX(1, strtol, "+35", 10, 35, -1, 0); break;
+ CASE_TEST(strtol_negative); EXPECT_STRTOX(1, strtol, "-35", 10, -35, -1, 0); break;
+ CASE_TEST(strtol_hex_auto); EXPECT_STRTOX(1, strtol, "0xFF", 0, 255, -1, 0); break;
+ CASE_TEST(strtol_octal_auto); EXPECT_STRTOX(1, strtol, "011", 0, 9, -1, 0); break;
+ CASE_TEST(strtol_hex_00); EXPECT_STRTOX(1, strtol, "0x00", 16, 0, -1, 0); break;
+ CASE_TEST(strtol_hex_FF); EXPECT_STRTOX(1, strtol, "FF", 16, 255, -1, 0); break;
+ CASE_TEST(strtol_hex_ff); EXPECT_STRTOX(1, strtol, "ff", 16, 255, -1, 0); break;
+ CASE_TEST(strtol_hex_prefix); EXPECT_STRTOX(1, strtol, "0xFF", 16, 255, -1, 0); break;
+ CASE_TEST(strtol_trailer); EXPECT_STRTOX(1, strtol, "35foo", 10, 35, 2, 0); break;
+ CASE_TEST(strtol_overflow); EXPECT_STRTOX(1, strtol, "0x8000000000000000", 16, LONG_MAX, -1, ERANGE); break;
+ CASE_TEST(strtol_underflow); EXPECT_STRTOX(1, strtol, "-0x8000000000000001", 16, LONG_MIN, -1, ERANGE); break;
+ CASE_TEST(strtoul_negative); EXPECT_STRTOX(1, strtoul, "-0x1", 16, ULONG_MAX, 4, 0); break;
+ CASE_TEST(strtoul_overflow); EXPECT_STRTOX(1, strtoul, "0x10000000000000000", 16, ULONG_MAX, -1, ERANGE); break;
case __LINE__:
return ret; /* must be last */
--
2.44.0