X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=format_check.c;h=5580d9173039bbcfd4e4aa3eb923da8cce9ad37a;hb=b892fe35993bac602948920d326522068b7d1bfe;hp=9e991d8823ae6ce8e081a0ba9e55da987ea69ff4;hpb=54307704f0f38bba488540836a0c1893302a591b;p=cparser

diff --git a/format_check.c b/format_check.c
index 9e991d8..5580d91 100644
--- a/format_check.c
+++ b/format_check.c
@@ -21,12 +21,14 @@
 
 #include <ctype.h>
 
+#include "adt/strutil.h"
 #include "adt/util.h"
 #include "format_check.h"
 #include "symbol_t.h"
 #include "ast_t.h"
 #include "entity_t.h"
 #include "diagnostic.h"
+#include "parser.h"
 #include "types.h"
 #include "type_t.h"
 #include "warning.h"
@@ -107,7 +109,7 @@ static int internal_check_printf_format(const expression_t *fmt_expr,
                                         const call_argument_t *arg,
                                         const format_spec_t *spec)
 {
-	while (fmt_expr->kind == EXPR_UNARY_CAST_IMPLICIT) {
+	while (fmt_expr->kind == EXPR_UNARY_CAST) {
 		fmt_expr = fmt_expr->unary.value;
 	}
 
@@ -520,7 +522,7 @@ too_few_args:
 				}
 			} else if (get_unqualified_type(arg_skip) == expected_type_skip) {
 				goto next_arg;
-			} else if (arg->expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
+			} else if (arg->expression->kind == EXPR_UNARY_CAST) {
 				expression_t const *const expr        = arg->expression->unary.value;
 				type_t             *const unprom_type = skip_typeref(expr->base.type);
 				if (get_unqualified_type(unprom_type) == expected_type_skip) {
@@ -594,7 +596,7 @@ static void check_scanf_format(const call_argument_t *arg,
 	}
 
 	const expression_t *fmt_expr = arg->expression;
-	if (fmt_expr->kind == EXPR_UNARY_CAST_IMPLICIT) {
+	if (fmt_expr->kind == EXPR_UNARY_CAST) {
 		fmt_expr = fmt_expr->unary.value;
 	}
 
@@ -622,6 +624,23 @@ static void check_scanf_format(const call_argument_t *arg,
 
 		++num_fmt;
 
+		bool suppress_assignment = false;
+		if (fmt == '*') {
+			fmt = *++c;
+			suppress_assignment = true;
+		}
+
+		size_t width = 0;
+		if ('0' <= fmt && fmt <= '9') {
+			do {
+				width = width * 10 + (fmt - '0');
+				fmt   = *++c;
+			} while ('0' <= fmt && fmt <= '9');
+			if (width == 0) {
+				warningf(WARN_FORMAT, pos, "field width is zero at format %u", num_fmt);
+			}
+		}
+
 		/* look for length modifiers */
 		format_length_modifier_t fmt_mod = FMT_MOD_NONE;
 		switch (fmt) {
@@ -759,20 +778,32 @@ static void check_scanf_format(const call_argument_t *arg,
 				goto next_arg;
 			}
 			expected_type = type_wchar_t;
-			break;
+			goto check_c_width;
 
-		case 'c':
-			expected_type = type_int;
+		case 'c': {
 			switch (fmt_mod) {
-			case FMT_MOD_NONE: expected_type = type_int;     break; /* TODO promoted char */
-			case FMT_MOD_l:    expected_type = type_wint_t;  break;
+			case FMT_MOD_NONE: expected_type = type_char;    break;
+			case FMT_MOD_l:    expected_type = type_wchar_t; break;
 			case FMT_MOD_w:    expected_type = type_wchar_t; break;
 
 			default:
 				warn_invalid_length_modifier(pos, fmt_mod, fmt);
 				goto next_arg;
 			}
+
+check_c_width:
+			if (width == 0)
+				width = 1;
+			if (!suppress_assignment && arg != NULL) {
+				type_t *const type = skip_typeref(revert_automatic_type_conversion(arg->expression));
+				if (is_type_array(type)       &&
+				    type->array.size_constant &&
+				    width > type->array.size) {
+					warningf(WARN_FORMAT, pos, "target buffer '%T' is too small for %u characters at format %u", type, width, num_fmt);
+				}
+			}
 			break;
+		}
 
 		case 'S':
 			if (fmt_mod != FMT_MOD_NONE) {
@@ -783,7 +814,7 @@ static void check_scanf_format(const call_argument_t *arg,
 			break;
 
 		case 's':
-		case '[':
+		case '[': {
 			switch (fmt_mod) {
 				case FMT_MOD_NONE: expected_type = type_char;    break;
 				case FMT_MOD_l:    expected_type = type_wchar_t; break;
@@ -793,7 +824,19 @@ static void check_scanf_format(const call_argument_t *arg,
 					warn_invalid_length_modifier(pos, fmt_mod, fmt);
 					goto next_arg;
 			}
+
+			if (!suppress_assignment &&
+			    width != 0           &&
+			    arg   != NULL) {
+				type_t *const type = skip_typeref(revert_automatic_type_conversion(arg->expression));
+				if (is_type_array(type)       &&
+				    type->array.size_constant &&
+				    width >= type->array.size) {
+					warningf(WARN_FORMAT, pos, "target buffer '%T' is too small for %u characters and \\0 at format %u", type, width, num_fmt);
+				}
+			}
 			break;
+		}
 
 		case 'p':
 			if (fmt_mod != FMT_MOD_NONE) {
@@ -803,7 +846,11 @@ static void check_scanf_format(const call_argument_t *arg,
 			expected_type = type_void_ptr;
 			break;
 
-		case 'n':
+		case 'n': {
+			if (suppress_assignment) {
+				warningf(WARN_FORMAT, pos, "conversion '%n' cannot be suppressed with '*' at format %u", num_fmt);
+			}
+
 			switch (fmt_mod) {
 			case FMT_MOD_NONE: expected_type = type_int;         break;
 			case FMT_MOD_hh:   expected_type = type_signed_char; break;
@@ -819,14 +866,20 @@ static void check_scanf_format(const call_argument_t *arg,
 				goto next_arg;
 			}
 			break;
+		}
 
 		default:
 			warningf(WARN_FORMAT, pos, "encountered unknown conversion specifier '%%%c' at format %u", fmt, num_fmt);
+			if (suppress_assignment)
+				continue;
 			if (arg == NULL)
 				goto too_few_args;
 			goto next_arg;
 		}
 
+		if (suppress_assignment)
+			continue;
+
 		if (arg == NULL) {
 too_few_args:
 			warningf(WARN_FORMAT, pos, "too few arguments for format string");
@@ -951,7 +1004,7 @@ void check_format(const call_expression_t *const call)
 	 */
 	const char *const name = entity->base.symbol->string;
 	for (size_t i = 0; i < lengthof(builtin_table); ++i) {
-		if (strcmp(name, builtin_table[i].name) == 0) {
+		if (streq(name, builtin_table[i].name)) {
 			switch (builtin_table[i].fmt_kind) {
 			case FORMAT_PRINTF:
 				check_printf_format(arg, &builtin_table[i]);