os: support pnprintf length modifiers for integers

Mainly for %ld, smaller than int is propagated anyway, and %lld isn't really
used.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>

1 files changed, 86 insertions, 4 deletions

diff --git a/os/log.c b/os/log.c
index dc6e2888b..df025fbca 100644
--- a/os/log.c
+++ b/os/log.c
@@ -279,6 +279,55 @@ LogSetParameter(LogParameter param, int value)
     }
 }
 
+enum {
+    LMOD_LONG     = 0x1,
+    LMOD_LONGLONG = 0x2,
+    LMOD_SHORT    = 0x4,
+    LMOD_SIZET    = 0x8,
+};
+
+/**
+ * Parse non-digit length modifiers and set the corresponding flag in
+ * flags_return.
+ *
+ * @return the number of bytes parsed
+ */
+static int parse_length_modifier(const char *format, size_t len, int *flags_return)
+{
+    int idx = 0;
+    int length_modifier = 0;
+
+    while (idx < len) {
+        switch (format[idx]) {
+            case 'l':
+                BUG_RETURN_VAL(length_modifier & LMOD_SHORT, 0);
+
+                if (length_modifier & LMOD_LONG)
+                    length_modifier |= LMOD_LONGLONG;
+                else
+                    length_modifier |= LMOD_LONG;
+                break;
+            case 'h':
+                BUG_RETURN_VAL(length_modifier & (LMOD_LONG|LMOD_LONGLONG), 0);
+                length_modifier |= LMOD_SHORT;
+                /* gcc says 'short int' is promoted to 'int' when
+                 * passed through '...', so ignored during
+                 * processing */
+                break;
+            case 'z':
+                length_modifier |= LMOD_SIZET;
+                break;
+            default:
+                goto out;
+        }
+        idx++;
+    }
+
+out:
+    *flags_return = length_modifier;
+    return idx;
+}
+
 /**
  * Signal-safe snprintf, with some limitations over snprintf. Be careful
  * which directives you use.
@@ -297,6 +346,7 @@ pnprintf(char *string, size_t size, const char *f, va_list args)
     int64_t si;
 
     for (; f_idx < f_len && s_idx < size - 1; f_idx++) {
+        int length_modifier = 0;
         if (f[f_idx] != '%') {
             string[s_idx++] = f[f_idx];
             continue;
@@ -304,10 +354,18 @@ pnprintf(char *string, size_t size, const char *f, va_list args)
 
         f_idx++;
 
-        /* silently swallow length modifiers */
+        /* silently swallow digit length modifiers */
         while (f_idx < f_len && ((f[f_idx] >= '0' && f[f_idx] <= '9') || f[f_idx] == '.'))
             f_idx++;
 
+        /* non-digit length modifiers */
+        if (f_idx < f_len) {
+            int parsed_bytes = parse_length_modifier(&f[f_idx], f_len - f_idx, &length_modifier);
+            if (parsed_bytes < 0)
+                return 0;
+            f_idx += parsed_bytes;
+        }
+
         if (f_idx >= f_len)
             break;
 
@@ -321,7 +379,15 @@ pnprintf(char *string, size_t size, const char *f, va_list args)
             break;
 
         case 'u':
-            ui = va_arg(args, unsigned);
+            if (length_modifier & LMOD_LONGLONG)
+                ui = va_arg(args, unsigned long long);
+            else if (length_modifier & LMOD_LONG)
+                ui = va_arg(args, unsigned long);
+            else if (length_modifier & LMOD_SIZET)
+                ui = va_arg(args, size_t);
+            else
+                ui = va_arg(args, unsigned);
+
             FormatUInt64(ui, number);
             p_len = strlen_sigsafe(number);
 
@@ -330,7 +396,15 @@ pnprintf(char *string, size_t size, const char *f, va_list args)
             break;
         case 'i':
         case 'd':
-            si = va_arg(args, int);
+            if (length_modifier & LMOD_LONGLONG)
+                si = va_arg(args, long long);
+            else if (length_modifier & LMOD_LONG)
+                si = va_arg(args, long);
+            else if (length_modifier & LMOD_SIZET)
+                si = va_arg(args, ssize_t);
+            else
+                si = va_arg(args, int);
+
             FormatInt64(si, number);
             p_len = strlen_sigsafe(number);
 
@@ -351,7 +425,15 @@ pnprintf(char *string, size_t size, const char *f, va_list args)
             break;
 
         case 'x':
-            ui = va_arg(args, unsigned);
+            if (length_modifier & LMOD_LONGLONG)
+                ui = va_arg(args, unsigned long long);
+            else if (length_modifier & LMOD_LONG)
+                ui = va_arg(args, unsigned long);
+            else if (length_modifier & LMOD_SIZET)
+                ui = va_arg(args, size_t);
+            else
+                ui = va_arg(args, unsigned);
+
             FormatUInt64Hex(ui, number);
             p_len = strlen_sigsafe(number);