Linux-Sparse Archive on lore.kernel.org
 help / color / Atom feed
From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: linux-sparse@vger.kernel.org
Cc: Ben Dooks <ben.dooks@codethink.co.uk>,
	Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [PATCH 11/13] format-check: add a function to check the type of integers
Date: Wed, 14 Oct 2020 01:22:29 +0200
Message-ID: <20201013232231.10349-12-luc.vanoostenryck@gmail.com> (raw)
In-Reply-To: <20201013232231.10349-1-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


  parent reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-13 23:22 [PATCH 00/13] format-check: add specific type checking Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 01/13] format-check: void * is not OK for strings, fix the test Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 02/13] format-check: more complete parsing of the length & type modifiers Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 03/13] format-check: add helper type_class() Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 04/13] format-check: merge 'fmt_string' & 'string' Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 05/13] format-check: remove unneeded member: target Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 06/13] format-check: add a function to check to type of strings Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 07/13] format-check: add a function to check to type of 'n' arguments Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 08/13] format-check: add a function to check to type of pointers Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 09/13] format-check: remove printf_fmt_print_pointer() Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 10/13] format-check: add a function to check the type of floats Luc Van Oostenryck
2020-10-13 23:22 ` Luc Van Oostenryck [this message]
2020-10-13 23:22 ` [PATCH 12/13] format-check: remove wrappers around type checking methods Luc Van Oostenryck
2020-10-13 23:22 ` [PATCH 13/13] format-check: simplify calling of parse_printf_get_fmt() Luc Van Oostenryck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201013232231.10349-12-luc.vanoostenryck@gmail.com \
    --to=luc.vanoostenryck@gmail.com \
    --cc=ben.dooks@codethink.co.uk \
    --cc=linux-sparse@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Sparse Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-sparse/0 linux-sparse/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-sparse linux-sparse/ https://lore.kernel.org/linux-sparse \
		linux-sparse@vger.kernel.org
	public-inbox-index linux-sparse

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-sparse


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git