{"id":59,"date":"2010-11-02T18:15:43","date_gmt":"2010-11-02T12:45:43","guid":{"rendered":"http:\/\/compilerart.org\/?p=59"},"modified":"2010-11-02T18:15:43","modified_gmt":"2010-11-02T12:45:43","slug":"gcc-limits-and","status":"publish","type":"post","link":"https:\/\/www.trueangle.org\/index.php\/2010\/11\/02\/gcc-limits-and\/","title":{"rendered":"gcc limits and -Wformat"},"content":{"rendered":"
\n\"\"<\/a>
\n
\n#include <stdio.h>
\n#include <limits.h>
\nint main (void)
\n{
\n unsigned long ul = LONG_MAX;
\n short int si = SHRT_MIN;
\n printf (\"%d\\n\", ul);
\n printf (\"%s\\n\", si);
\n return 0;
\n}
\n<\/code>\n<\/div>\n


\n$gcc printme.c
\n$.\/a.out
\n-1
\nSegmentation fault
\n$gcc printme.c -Wformat
\nprintme.c: In function \u2018main\u2019:
\nprintme.c:7: warning: format \u2018%d\u2019 expects type \u2018int\u2019, but argument 2 has type \u2018long unsigned int\u2019
\nprintme.c:8: warning: format \u2018%s\u2019 expects type \u2018char *\u2019, but argument 2 has type \u2018int\u2019
\n $
\n<\/code><\/p>\n

\nThe <limits.h> header shall define various symbolic names.\nThe names represent various limits on resources that the\nimplementation imposes on applications.\n\nabout \"-Wformat\"\nCheck calls to printf and scanf, etc., to make sure that the\narguments supplied have types appropriate to the format\nstring specified, and that the conversions specified in the\nformat string make sense\n <\/pre>\n
\nReference\/Source:\nThe Definitive Guide to GCC Second Edition\nWilliam von Hagen\nhttp:\/\/www.opengroup.org\/onlinepubs\/009695399\/basedefs\/limits.h.html\nhttp:\/\/gcc.gnu.org\/onlinedocs\/gcc\/Warning-Options.html\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
#include <stdio.h> #include <limits.h> int main (void) { unsigned long ul = LONG_MAX; short int si = SHRT_MIN; printf (“%d\\n”, ul); printf (“%s\\n”, si); return 0; } $gcc printme.c $.\/a.out -1 Segmentation fault $gcc printme.c -Wformat printme.c: In function \u2018main\u2019: printme.c:7: warning: format \u2018%d\u2019 expects type \u2018int\u2019, but argument 2 has type \u2018long unsigned int\u2019 … <\/p>\n
Continue reading “gcc limits and -Wformat”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/59"}],"collection":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/comments?post=59"}],"version-history":[{"count":0,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/59\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/media?parent=59"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/categories?post=59"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/tags?post=59"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}