[PATCH 11/13] format-check: add a function to check the type of integers

[Luc Van Oostenryck <luc.vanoostenryck@gmail.com>]

This checking is currently done by check_assignment_types()
for all numeric types but this is not adequate because we
want to have a better control over what is allowed or not

So, add a custom checking function:
*) checking if the argument is one of the integer types.
*) currently accepting bitwise types too
*) easily extended to handle -Wformat-signedness

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 verify-format.c | 74 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 69 insertions(+), 5 deletions(-)

diff --git a/verify-format.c b/verify-format.c
index 6bcbfdfef1b4..fdfe9c22e858 100644
--- a/verify-format.c
+++ b/verify-format.c
@@ -98,12 +98,76 @@ static inline int type_class(struct symbol *type, struct symbol **base)
 	return CLASS_OTHER;
 }
 
-static int printf_fmt_numtype(struct format_type *fmt,
+static struct symbol *normalize_sint(struct symbol *s)
+{
+	if (s == &sint_ctype)
+		return &int_ctype;
+	if (s == &slong_ctype)
+		return &long_ctype;
+	if (s == &sllong_ctype)
+		return &llong_ctype;
+	if (s == &sint128_ctype)
+		return &int128_ctype;
+	return s;
+}
+
+static struct symbol *normalize_uint(struct symbol *s)
+{
+	if (s == &uint_ctype)
+		return &int_ctype;
+	if (s == &ulong_ctype)
+		return &long_ctype;
+	if (s == &ullong_ctype)
+		return &llong_ctype;
+	if (s == &uint128_ctype)
+		return &int128_ctype;
+	return s;
+}
+
+static const char *check_printf_int(struct format_type *fmt, struct symbol *source, int sign)
+{
+	const char *typediff = "different base types";
+	struct symbol *target = fmt->type;
+	int class = type_class(source, &source);
+
+	if (class == CLASS_BITWISE)
+		class = type_class(source->ctype.base_type, &source);
+	if (class != CLASS_INT)
+		return typediff;
+
+	// For now, ignore the signedness
+	target = normalize_uint(target);
+	source = normalize_uint(source);
+	source = normalize_sint(source);
+	if (source == target)
+		return NULL;
+	return typediff;
+}
+
+static const char *check_printf_sint(struct format_type *fmt, struct symbol *source)
+{
+	return check_printf_int(fmt, source, 1);
+}
+
+static int printf_fmt_sint(struct format_type *fmt,
+			      struct expression **expr,
+			      struct symbol *ctype,
+			      const char **typediff)
+{
+	return !(*typediff = check_printf_sint(fmt, ctype));
+}
+
+static const char *check_printf_uint(struct format_type *fmt, struct symbol *source)
+{
+	return check_printf_int(fmt, source, 0);
+}
+
+static int printf_fmt_uint(struct format_type *fmt,
 			      struct expression **expr,
 			      struct symbol *ctype,
 			      const char **typediff)
 {
-	return check_assignment_types(fmt->type, expr, typediff);
+	return !(*typediff = check_printf_uint(fmt, ctype));
 }
 
 static const char *check_printf_float(struct format_type *fmt, struct symbol *source)
@@ -274,7 +338,7 @@ static struct format_type *parse_printf_get_fmt(struct format_type *type,
 
 	switch (*ptr++) {
 	case 'd': case 'i':
-		type->test = printf_fmt_numtype;
+		type->test = printf_fmt_sint;
 		switch (szmod) {
 		case LEN_hh:
 		case LEN_h:
@@ -302,7 +366,7 @@ static struct format_type *parse_printf_get_fmt(struct format_type *type,
 		}
 		break;
 	case 'u': case 'o': case 'x': case 'X':
-		type->test = printf_fmt_numtype;
+		type->test = printf_fmt_uint;
 		switch (szmod) {
 		case LEN_hh:
 		case LEN_h:
@@ -344,7 +408,7 @@ static struct format_type *parse_printf_get_fmt(struct format_type *type,
 		}
 		break;
 	case 'c':
-		type->test = printf_fmt_numtype;
+		type->test = printf_fmt_sint;	// FIXME: need its own check?
 		switch (szmod) {
 		case LEN_none:
 			type->type = &int_ctype;
-- 
2.28.0