From: Nikos Nikoleris <nikos.nikoleris@arm.com>
To: kvm@vger.kernel.org
Cc: andrew.jones@linux.dev, drjones@redhat.com, pbonzini@redhat.com,
jade.alglave@arm.com, alexandru.elisei@arm.com,
ricarkol@google.com
Subject: [kvm-unit-tests PATCH v3 12/27] lib/printf: Support for precision modifier in printf
Date: Thu, 30 Jun 2022 11:03:09 +0100 [thread overview]
Message-ID: <20220630100324.3153655-13-nikos.nikoleris@arm.com> (raw)
In-Reply-To: <20220630100324.3153655-1-nikos.nikoleris@arm.com>
This follows the typical format of:
printf("%.Ns", *str);
Where N might be a decimal digit string or '*'. This feature is used
by a future change.
See also: man 3 printf
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
---
lib/printf.c | 95 ++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 78 insertions(+), 17 deletions(-)
diff --git a/lib/printf.c b/lib/printf.c
index 383799e..d600199 100644
--- a/lib/printf.c
+++ b/lib/printf.c
@@ -6,6 +6,7 @@
*/
#include "libcflat.h"
+#include "ctype.h"
#define BUFSZ 2000
@@ -19,6 +20,7 @@ typedef struct strprops {
char pad;
int npad;
bool alternate;
+ int precision;
} strprops_t;
static void addchar(pstream_t *p, char c)
@@ -43,7 +45,7 @@ static void print_str(pstream_t *p, const char *s, strprops_t props)
}
}
- while (*s)
+ while (*s && props.precision--)
addchar(p, *s++);
if (npad < 0) {
@@ -73,12 +75,13 @@ static void print_int(pstream_t *ps, long long n, int base, strprops_t props)
n /= base;
}
+ while (p == buf || (p - buf < props.precision))
+ *p++ = '0';
+ props.precision = -1;
+
if (s)
*p++ = '-';
- if (p == buf)
- *p++ = '0';
-
for (i = 0; i < (p - buf) / 2; ++i) {
char tmp;
@@ -104,8 +107,13 @@ static void print_unsigned(pstream_t *ps, unsigned long long n, int base,
}
if (p == buf)
+ props.alternate = false;
+
+ while (p == buf || (p - buf < props.precision))
*p++ = '0';
- else if (props.alternate && base == 16) {
+ props.precision = -1;
+
+ if (props.alternate && base == 16) {
if (props.pad == '0') {
addchar(ps, '0');
addchar(ps, 'x');
@@ -147,9 +155,56 @@ static int fmtnum(const char **fmt)
return num;
}
+/*
+ * Adapted from drivers/firmware/efi/libstub/vsprintf.c
+ */
+static int skip_atoi(const char **s)
+{
+ int i = 0;
+
+ do {
+ i = i*10 + *((*s)++) - '0';
+ } while (isdigit(**s));
+
+ return i;
+}
+
+/*
+ * Adapted from drivers/firmware/efi/libstub/vsprintf.c
+ */
+static int get_int(const char **fmt, va_list *ap)
+{
+ if (isdigit(**fmt))
+ return skip_atoi(fmt);
+
+ if (**fmt == '*') {
+ ++(*fmt);
+ /* it's the next argument */
+ return va_arg(*ap, int);
+ }
+ return 0;
+}
+
int vsnprintf(char *buf, int size, const char *fmt, va_list va)
{
pstream_t s;
+ va_list args;
+
+ /*
+ * We want to pass our input va_list to helper functions by reference,
+ * but there's an annoying edge case. If va_list was originally passed
+ * to us by value, we could just pass &ap down to the helpers. This is
+ * the case on, for example, X86_32.
+ * However, on X86_64 (and possibly others), va_list is actually a
+ * size-1 array containing a structure. Our function parameter ap has
+ * decayed from T[1] to T*, and &ap has type T** rather than T(*)[1],
+ * which is what will be expected by a function taking a va_list *
+ * parameter.
+ * One standard way to solve this mess is by creating a copy in a local
+ * variable of type va_list and then passing a pointer to that local
+ * copy instead, which is what we do here.
+ */
+ va_copy(args, va);
s.buffer = buf;
s.remain = size - 1;
@@ -160,6 +215,7 @@ int vsnprintf(char *buf, int size, const char *fmt, va_list va)
strprops_t props;
memset(&props, 0, sizeof(props));
props.pad = ' ';
+ props.precision = -1;
if (f != '%') {
addchar(&s, f);
@@ -172,11 +228,15 @@ morefmt:
addchar(&s, '%');
break;
case 'c':
- addchar(&s, va_arg(va, int));
+ addchar(&s, va_arg(args, int));
break;
case '\0':
--fmt;
break;
+ case '.':
+ props.pad = ' ';
+ props.precision = get_int(&fmt, &args);
+ goto morefmt;
case '#':
props.alternate = true;
goto morefmt;
@@ -204,54 +264,55 @@ morefmt:
case 'd':
switch (nlong) {
case 0:
- print_int(&s, va_arg(va, int), 10, props);
+ print_int(&s, va_arg(args, int), 10, props);
break;
case 1:
- print_int(&s, va_arg(va, long), 10, props);
+ print_int(&s, va_arg(args, long), 10, props);
break;
default:
- print_int(&s, va_arg(va, long long), 10, props);
+ print_int(&s, va_arg(args, long long), 10, props);
break;
}
break;
case 'u':
switch (nlong) {
case 0:
- print_unsigned(&s, va_arg(va, unsigned), 10, props);
+ print_unsigned(&s, va_arg(args, unsigned int), 10, props);
break;
case 1:
- print_unsigned(&s, va_arg(va, unsigned long), 10, props);
+ print_unsigned(&s, va_arg(args, unsigned long), 10, props);
break;
default:
- print_unsigned(&s, va_arg(va, unsigned long long), 10, props);
+ print_unsigned(&s, va_arg(args, unsigned long long), 10, props);
break;
}
break;
case 'x':
switch (nlong) {
case 0:
- print_unsigned(&s, va_arg(va, unsigned), 16, props);
+ print_unsigned(&s, va_arg(args, unsigned int), 16, props);
break;
case 1:
- print_unsigned(&s, va_arg(va, unsigned long), 16, props);
+ print_unsigned(&s, va_arg(args, unsigned long), 16, props);
break;
default:
- print_unsigned(&s, va_arg(va, unsigned long long), 16, props);
+ print_unsigned(&s, va_arg(args, unsigned long long), 16, props);
break;
}
break;
case 'p':
props.alternate = true;
- print_unsigned(&s, (unsigned long)va_arg(va, void *), 16, props);
+ print_unsigned(&s, (unsigned long)va_arg(args, void *), 16, props);
break;
case 's':
- print_str(&s, va_arg(va, const char *), props);
+ print_str(&s, va_arg(args, const char *), props);
break;
default:
addchar(&s, f);
break;
}
}
+ va_end(args);
*s.buffer = 0;
return s.added;
}
--
2.25.1
next prev parent reply other threads:[~2022-06-30 10:04 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-30 10:02 [kvm-unit-tests PATCH v3 00/27] EFI and ACPI support for arm64 Nikos Nikoleris
2022-06-30 10:02 ` [kvm-unit-tests PATCH v3 01/27] lib: Fix style for acpi.{c,h} Nikos Nikoleris
2022-07-01 9:27 ` Andrew Jones
2022-07-01 9:52 ` Nikos Nikoleris
2022-07-01 10:12 ` Andrew Jones
2022-06-30 10:02 ` [kvm-unit-tests PATCH v3 02/27] x86: Avoid references to fields of ACPI tables Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 03/27] lib: Ensure all struct definition for ACPI tables are packed Nikos Nikoleris
2022-07-01 9:35 ` Andrew Jones
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 04/27] lib: Add support for the XSDT ACPI table Nikos Nikoleris
2022-07-01 9:49 ` Andrew Jones
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 05/27] lib: Extend the definition of the ACPI table FADT Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 06/27] devicetree: Check if fdt is NULL before returning that a DT is available Nikos Nikoleris
2022-07-01 9:55 ` Andrew Jones
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 07/27] arm/arm64: Add support for setting up the PSCI conduit through ACPI Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 08/27] arm/arm64: Add support for discovering the UART " Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 09/27] arm/arm64: Add support for timer initialization " Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 10/27] arm/arm64: Add support for cpu " Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 11/27] arm/arm64: Add support for gic " Nikos Nikoleris
2022-06-30 10:03 ` Nikos Nikoleris [this message]
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 13/27] lib/printf: Add support for printing wide strings Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 14/27] lib/efi: Add support for getting the cmdline Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 15/27] arm/arm64: mmu_disable: Clean and invalidate before disabling Nikos Nikoleris
2022-06-30 10:20 ` Alexandru Elisei
2022-06-30 11:08 ` Nikos Nikoleris
2022-06-30 11:24 ` Alexandru Elisei
2022-06-30 15:16 ` Nikos Nikoleris
2022-06-30 15:57 ` Alexandru Elisei
2022-07-01 9:12 ` Andrew Jones
2022-07-01 10:24 ` Alexandru Elisei
2022-07-01 11:16 ` Andrew Jones
2022-07-11 14:23 ` Alexandru Elisei
2022-07-01 11:34 ` Nikos Nikoleris
2022-07-01 14:39 ` Alexandru Elisei
2022-07-01 10:36 ` Andrew Jones
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 16/27] arm/arm64: Rename etext to _etext Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 17/27] lib: Avoid ms_abi for calls related to EFI on arm64 Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 18/27] arm64: Add a new type of memory type flag MR_F_RESERVED Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 19/27] arm/arm64: Add a setup sequence for systems that boot through EFI Nikos Nikoleris
2022-06-30 10:54 ` Alexandru Elisei
2022-07-19 14:08 ` Alexandru Elisei
2022-08-12 14:34 ` Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 20/27] arm64: Copy code from GNU-EFI Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 21/27] arm64: Change GNU-EFI imported file to use defined types Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 22/27] arm64: Use code from the gnu-efi when booting with EFI Nikos Nikoleris
2022-07-01 0:43 ` Ricardo Koller
2022-07-04 9:18 ` Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 23/27] lib: Avoid external dependency in libelf Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 24/27] x86: Move x86_64-specific EFI CFLAGS to x86_64 Makefile Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 25/27] arm64: Add support for efi in Makefile Nikos Nikoleris
2022-07-12 13:39 ` Alexandru Elisei
2022-07-12 20:50 ` Nikos Nikoleris
2022-07-13 8:46 ` Alexandru Elisei
2022-07-13 9:17 ` Nikos Nikoleris
2022-07-15 13:59 ` Nikos Nikoleris
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 26/27] lib: arm: Print test exit status Nikos Nikoleris
2022-07-01 10:48 ` Andrew Jones
2022-06-30 10:03 ` [kvm-unit-tests PATCH v3 27/27] arm64: Add an efi/run script Nikos Nikoleris
2022-07-19 15:28 ` [kvm-unit-tests PATCH v3 00/27] EFI and ACPI support for arm64 Alexandru Elisei
2022-07-22 10:57 ` Nikos Nikoleris
2022-07-22 14:41 ` Alexandru Elisei
2022-08-01 18:23 ` Nikos Nikoleris
2022-08-02 10:19 ` Alexandru Elisei
2022-08-02 10:46 ` Andrew Jones
2022-08-03 12:51 ` Nikos Nikoleris
2022-08-09 11:16 ` Alexandru Elisei
2022-08-09 15:29 ` Sean Christopherson
2022-08-10 9:17 ` Alexandru Elisei
2022-08-10 14:58 ` Sean Christopherson
2022-08-10 15:04 ` Alexandru Elisei
2022-08-09 16:09 ` Nikos Nikoleris
2022-08-12 14:55 ` Alexandru Elisei
2022-08-12 15:49 ` Nikos Nikoleris
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