Why does GCC not complain about _Bool in c89 mode? -


why following command produce no warnings or errors, though _bool not part of c89?

  $ echo "_bool x;" | gcc -x c -c -std=c89 -pedantic -wall -wextra -

for comparison, changing _bool bool results in error:

  $ echo "bool x;" | gcc -x c -c -std=c89 -pedantic -wall -wextra -   <stdin>:1:6: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘x’

this happens on cygwin [gcc (gcc) 4.5.3] , linux [gcc (gcc) 4.1.2 20080704 (red hat 4.1.2-54)].

using _bool in c89 compiler invokes undefined behavior because use identifier starting underscore , upper case letter. don't have paper copy of c89 handy, expect same c99 7.1.3:

— identifiers begin underscore , either uppercase letter or underscore reserved use.

one permissible undefined behavior accepting _bool without diagnostic. gnu extension.

of course, bool doesn't fall implementation namespace, must diagnosed unless declared.


Comments

Post a Comment

Popular posts from this blog

Change php variable from jquery value using ajax (same page) -

what i'm trying this: i've php global variable $currentid , simple jquery script check if there "id" (page) in hash of url , if yes wanted give value $currentid . i've been reading lot , notice shall use ajax i'm not managing it. my code is: <script type="text/javascript"> $(document).ready(function(){ if (parent.location.hash != '' ) { var thecurrentid = parent.location.hash.split('#')[1]; $.ajax({ url: 'my.php', //current page type: 'post', data: {theid: thecurrentid }, datatype: 'json', success: function () { } }); } // code here }); </script> could me please? thank in advance. php server side language, meaning once has sent data browser, php variables , data cannot changed... however, using ajax, can send request php page , change data in dom based on result. consider th...
Read more

How can I fetch data from a web server in an android application? -

i want retrieve data web server in android application, , don't know begin. should use web services? i recommend these tutorials: connect android php , mysql , json in android , php , mysqli i used these tutorials , managed trying working without difficulty. between them describe each step in how attempting @ each stage, android application, database , web server side , has information included can process , use received information the thing add connect android php , mysql tutorial makes use of mysql_ in php deprecated. better use mysqli why included third link. the basic outline of want this: 1) in android app make request server php script using class this: import java.io.bufferedreader; import java.io.ioexception; import java.io.inputstream; import java.io.inputstreamreader; import java.io.unsupportedencodingexception; import java.util.list; import org.apache.http.httpentity; import org.apache.http.httpresponse; import org.apache.http.namevaluepair...
Read more

jquery - How can I dynamically add a browser tab? -

since using iframes house external pages are, accounts "not preferred method" , disallowed sites (flickr, one), want dynamically generate browser tabs. e.g., when user submits form, want dynamically generate tab on browser in response submitted. e.g., might want add new tab url like: http://www.bigsurgarrapata.com/contact how in jquery? you want form target attribute action attribute. http://www.w3schools.com/tags/att_form_target.asp browsers have ultimate control on result of target attribute open new tab value of _blank. <form action="contact_submit.php" target="_blank" method="post">
Read more