From 9cf3079b95ad7e995880ec5553372191c73efb0e Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Thu, 15 Sep 2022 22:36:43 +0200
Subject: shared/printf: properly implement number precision
---
src/shared/printf.c | 67 +++++++++++++++++++++-----------------
src/user/app/tests/shared/printf.c | 30 +++++++++++------
2 files changed, 57 insertions(+), 40 deletions(-)
diff --git a/src/shared/printf.c b/src/shared/printf.c
index d28f891..9ab4606 100644
--- a/src/shared/printf.c
+++ b/src/shared/printf.c
@@ -18,6 +18,13 @@ struct out_state {
size_t cpos, clen;
};
+struct mods {
+ char fill_char;
+ size_t field_width;
+ size_t precision;
+};
+
+
static int flush(struct out_state *os) {
if (os->cpos) {
os->back(os->backarg, os->cache, os->cpos);
@@ -38,19 +45,25 @@ static void output(struct out_state *os, const char *buf, size_t len) {
os->written += len;
}
-static void output_c(struct out_state *os, char c) {
- output(os, &c, 1);
+static void output_c(struct out_state *os, char c, int amt) {
+ for (int i = 0; i < amt; i++)
+ output(os, &c, 1);
}
-struct mods {
- char fill_char;
- size_t field_width;
-};
-
static void pad(struct out_state *os, struct mods *m, size_t len) {
- for (size_t i = 0; len + i < m->field_width; i++)
- output(os, &m->fill_char, 1);
+ output_c(os, m->fill_char, m->field_width - len);
+}
+
+static void padnum(struct out_state *os, struct mods *m, size_t len, char sign) {
+ if (len < m->precision) {
+ output_c(os, m->fill_char, m->field_width - m->precision - (sign ? 1 : 0));
+ if (sign) output_c(os, sign, 1);
+ output_c(os, '0', m->precision - len);
+ } else {
+ output_c(os, m->fill_char, m->field_width - len - (sign ? 1 : 0));
+ if (sign) output_c(os, sign, 1);
+ }
}
static void output_uint(struct out_state *os, struct mods *m, unsigned long long n, char sign) {
@@ -64,9 +77,9 @@ static void output_uint(struct out_state *os, struct mods *m, unsigned long long
buf[--pos] = r + '0';
n = q;
}
- if (sign) buf[--pos] = sign;
- pad(os, m, sizeof(buf) - pos);
- output(os, buf + pos, sizeof(buf) - pos);
+ size_t len = sizeof(buf) - pos;
+ padnum(os, m, len, sign);
+ output(os, buf + pos, len);
}
@@ -95,6 +108,7 @@ int __printf_internal(const char *fmt, va_list argp,
struct mods m = {
.fill_char = ' ',
.field_width = 0,
+ .precision = 0,
};
for (bool modifier = true; modifier;) {
@@ -116,18 +130,14 @@ int __printf_internal(const char *fmt, va_list argp,
}
if (c == '.') {
- // TODO implement precision properly, this violates the spec and is stupid
c = *fmt++;
- m.fill_char = '0';
- m.field_width = 0;
while ('0' <= c && c <= '9') {
- m.field_width *= 10;
- m.field_width += c - '0';
+ m.precision *= 10;
+ m.precision += c - '0';
c = *fmt++;
}
}
- // TODO length modifiers
enum lenmod lm;
switch (c) {
case 'l':
@@ -149,18 +159,15 @@ int __printf_internal(const char *fmt, va_list argp,
char sign;
case 'c':
- output_c(&os, va_arg(argp, int));
+ output_c(&os, va_arg(argp, int), 1);
break;
case 's':
const char *s = va_arg(argp, char*);
- if (s) {
- len = strlen(s);
- pad(&os, &m, len);
- output(&os, s, len);
- } else {
- pad(&os, &m, 0);
- }
+ if (s == NULL) s = "(null)";
+ len = strlen(s);
+ pad(&os, &m, len);
+ output(&os, s, len);
break;
case 'x':
@@ -170,11 +177,11 @@ int __printf_internal(const char *fmt, va_list argp,
len = 1;
while (n >> (len * 4) && (len * 4) < (sizeof(n) * 8))
len++;
- pad(&os, &m, len);
+ padnum(&os, &m, len, '\0');
while (len-- > 0) {
char h = '0' + ((n >> (len * 4)) & 0xf);
if (h > '9') h += 'a' - '9' - 1;
- output_c(&os, h);
+ output_c(&os, h, 1);
}
break;
@@ -182,7 +189,7 @@ int __printf_internal(const char *fmt, va_list argp,
if (lm == LM_int) n = va_arg(argp, unsigned int);
else if (lm == LM_long) n = va_arg(argp, unsigned long);
else if (lm == LM_longlong) n = va_arg(argp, unsigned long long);
- output_uint(&os, &m, n, 0);
+ output_uint(&os, &m, n, '\0');
break;
case 'd':
@@ -190,7 +197,7 @@ int __printf_internal(const char *fmt, va_list argp,
if (lm == LM_int) ns = va_arg(argp, int);
else if (lm == LM_long) ns = va_arg(argp, long);
else if (lm == LM_longlong) ns = va_arg(argp, long long);
- sign = 0;
+ sign = '\0';
if (ns < 0) {
ns = -ns;
sign = '-';
diff --git a/src/user/app/tests/shared/printf.c b/src/user/app/tests/shared/printf.c
index 4e5ffb8..37b9679 100644
--- a/src/user/app/tests/shared/printf.c
+++ b/src/user/app/tests/shared/printf.c
@@ -23,16 +23,26 @@ static void test_printf(void) {
snprintf(buf, sizeof buf, "%s%%%s", "ab", "cd");
test(!strcmp(buf, "ab%cd"));
- snprintf(buf, sizeof buf, "%05u %05u", 1234, 56789);
- test(!strcmp(buf, "01234 56789"));
-
- snprintf(buf, sizeof buf, "%5d %5d", 123, 4567);
- test(!strcmp(buf, " 123 4567"));
- snprintf(buf, sizeof buf, "%5d %5d", -123, -4567);
- test(!strcmp(buf, " -123 -4567"));
-
- snprintf(buf, sizeof buf, "%u %d %x", 0, 0, 0);
- test(!strcmp(buf, "0 0 0"));
+ snprintf(buf, sizeof buf, "%05u,%05u", 1234, 56789);
+ test(!strcmp(buf, "01234,56789"));
+
+ snprintf(buf, sizeof buf, "%5d,%5d", 123, 4567);
+ test(!strcmp(buf, " 123, 4567"));
+ snprintf(buf, sizeof buf, "%5d,%5d", -123, -4567);
+ test(!strcmp(buf, " -123,-4567"));
+
+ snprintf(buf, sizeof buf, "%u,%d,%x", 0, 0, 0);
+ test(!strcmp(buf, "0,0,0"));
+
+ /* precision */
+ snprintf(buf, sizeof buf, "%5.2u,%5.2d,%5.2x", 0, 0, 0);
+ test(!strcmp(buf, " 00, 00, 00"));
+ snprintf(buf, sizeof buf, "%5.2u,%5.2d,%5.2x", 10, -10, 0x10);
+ test(!strcmp(buf, " 10, -10, 10"));
+ snprintf(buf, sizeof buf, "%5.3d", -1);
+ test(!strcmp(buf, " -001"));
+ snprintf(buf, sizeof buf, "%.5d", 123);
+ test(!strcmp(buf, "00123"));
}
void r_s_printf(void) {
--
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