C Error Redeclaration With No Linkage
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more redeclaration in c about Stack Overflow the company Business Learn more about hiring developers or posting ads for loop initial declarations are only allowed in c99 mode with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Error : Redeclaration with no linkage up vote 4 down vote favorite #include int x=13; // forcing space allocation int x; int main(){ printf("%d\n",x); } The code above compiles but the one below does not. why ? #include int main(){ int x=13; // forcing space allocation int x; printf("%d\n",x); } i was told that int x ; can be interpreted by the complier as a declaration or definition depending on the context . i can see that in the first case(global one) but what happens in the second. c share|improve this question edited Nov 14 '11 at 16:35 asked Nov 14 '11 at 16:25 Bazooka 6131818 add a comment| 3 Answers 3 active oldest votes up vote 4 down vote accepted Quoting: You can't have two global variables with the same name in C program. C might allow multiple definitions in the same file scope through the tentative definition rule, but in any case all definitions will refer to the same variable. share|improve this answer answered Nov 14 '11 at 16:36 Igor Oks 13k1761101 i agree with what you say. But why does not the same thing apply to the local variables. I thing i'm missing something very obvious. Please point in the right direction –Bazooka Nov 14 '11 at 16:41 you can have tentative definition only for variables that have file scope, and not for local variables. –Igor Oks Nov 14 '11 at 16:54 add a comment| up vote 0 down vote Because you can't declare twice a local variable with the same name. Simply don't do that. It works for the global one, as the compiler see that as a forward declaration, which of course cannot work with stack variable
question and get tips & solutions from a community of 418,461 IT Pros & Developers. It's quick & easy. redeclaration of 'p' with no linkage P: n/a Ravi #include int main(void) { int i, j, *p; i = 25; j = 100; int *p = &i; } When I compiled the above code with gcc I goth the message : "redeclaration of 'p' with no linkage" . What does this mean. Can You please explain? Aug 19 '07 #1 Post Reply Share this Question 6 Replies P: n/a pete Ravi wrote: > #include int main(void) { int i, j, *p; i = 25; j = 100; int *p = &i; } When I http://stackoverflow.com/questions/8124682/error-redeclaration-with-no-linkage compiled the above code with gcc I goth the message : "redeclaration of 'p' with no linkage" . What does this mean. It means that p has no linkage and that you declared p twice. Can You please explain? It's easier just to fix the code: #include int main(void) { int i, j, *p; i = 25; j = 100; p = &i; } -- pete Aug 19 '07 #2 P: n/a Mark McIntyre On Sun, 19 Aug https://bytes.com/topic/c/answers/695014-redeclaration-p-no-linkage 2007 14:43:13 -0000, in comp.lang.c , Ravi #include int main(void){ int i, j, *p; here you declared p as a pointr to an int. i = 25; j = 100; int *p = &i; here, you tried to declare it again. Both declarations don't specify the linkage - that is, they don't say that the object is extern (external linkage) or static (internal linkage) . Such objects have 'no linkage' and you can't have two of them in the same scope. See 6.2.2 of the Standard. -- Mark McIntyre "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." --Brian Kernighan Aug 19 '07 #3 P: n/a CBFalconer Ravi wrote: > #include int main(void) { int i, j, *p; i = 25; j = 100; int *p = &i; } When I compiled the above code with gcc I goth the message : "redeclaration of 'p' with no linkage" . What does this mean. Can You please explain? You already declared it in the first line. -- Chuck F (cbfalconer at maineline dot net) Available for consulting/temporary embedded and systems. -- Posted via a free Usenet account from http://www.teranews.com Aug 19 '07 #4 P: n/a Kenneth Brody Mark McIntyre wrote: > On Sun, 19 Aug 2007 14:43:13 -0000, i
i = 25; j = 100; int *p = &i; } When I compiled the above code with gcc I goth the message : "redeclaration of 'p' with no linkage" . What does this mean. Can You please explain? http://www.thecodingforums.com/threads/redeclaration-of-p-with-no-linkage.530309/ Ravi, Aug 19, 2007 #1 Advertisements pete Guest Ravi wrote: > > #include > int main(void) http://www.jmodelica.org/5073 > { > int i, j, *p; > i = 25; > j = 100; > int *p = &i; > } > > When I compiled the above code with gcc I goth the message : > "redeclaration of 'p' with no linkage" . > What does this mean. It means that p has no linkage and that you declared p twice. > Can in c You please explain? It's easier just to fix the code: #include int main(void) { int i, j, *p; i = 25; j = 100; p = &i; } -- pete pete, Aug 19, 2007 #2 Advertisements CBFalconer Guest Ravi wrote: > > #include > int main(void) { > int i, j, *p; > i = 25; > j = 100; > int *p = &i; > } > > When I compiled the above code with gcc I goth the c error redeclaration message : > "redeclaration of 'p' with no linkage" . > What does this mean. Can You please explain? You already declared it in the first line. -- Chuck F (cbfalconer at maineline dot net) Available for consulting/temporary embedded and systems. -- Posted via a free Usenet account from http://www.teranews.com CBFalconer, Aug 19, 2007 #3 Mark McIntyre Guest On Sun, 19 Aug 2007 14:43:13 -0000, in comp.lang.c , Ravi <> wrote: >#include >int main(void) >{ > int i, j, *p; here you declared p as a pointr to an int. > i = 25; > j = 100; > int *p = &i; here, you tried to declare it again. Both declarations don't specify the linkage - that is, they don't say that the object is extern (external linkage) or static (internal linkage) . Such objects have 'no linkage' and you can't have two of them in the same scope. See 6.2.2 of the Standard. -- Mark McIntyre "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." --Brian Kernighan Mark McIntyre, Aug 19, 2007 #4 Kenneth Brody Guest Mark McIntyre wrote: > > On Sun, 19 Aug 2007 14:43:13 -0000, in comp.lang.c , Ravi > <> wrote: > > >#include > >int main(void) > >{ > > int i, j, *p; > > here you dec
API Docs Optimica Compiler API Docs JMI API Docs Python API Docs Software Development Kit Test server DownloadJModelica.org platform JModelica.org SDK About Assimulo PyFMI FMI Library Log in Home » Forums » JModelica.org Development » Software Development Kit Error in C code generation 4 posts / 0 new Login or register to post comments Last post Fri, 2012-02-17 16:32 #1 esallberg Offline Joined: 2012-02-17 Error in C code generation When compiling a modelica model withFMU we get the following error in C code generation: --------------------------------- sources/BoilerJMWS3_Test_Modul1Simulation.c: In function 'model_ode_derivatives': sources/BoilerJMWS3_Test_Modul1Simulation.c:5096: warning: ISO C90 forbids mixed declarations and code sources/BoilerJMWS3_Test_Modul1Simulation.c:5101: error: redeclaration of 'tmp_var_17' with no linkage sources/BoilerJMWS3_Test_Modul1Simulation.c:5096: error: previous declaration of 'tmp_var_17' was here sources/BoilerJMWS3_Test_Modul1Simulation.c:5101: warning: ISO C90 forbids mixed declarations and code sources/BoilerJMWS3_Test_Modul1Simulation.c:5102: error: redeclaration of 'tmp_var_18' with no linkage sources/BoilerJMWS3_Test_Modul1Simulation.c:5097: error: previous declaration of 'tmp_var_18' was here sources/BoilerJMWS3_Test_Modul1Simulation.c:5108: error: redeclaration of 'tmp_var_17' with no linkage sources/BoilerJMWS3_Test_Modul1Simulation.c:5101: error: previous declaration of 'tmp_var_17' was here sources/BoilerJMWS3_Test_Modul1Simulation.c:5108: warning: ISO C90 forbids mixed declarations and code sources/BoilerJMWS3_Test_Modul1Simulation.c:5109: error: redeclaration of 'tmp_var_18' with no linkage sources/BoilerJMWS3_Test_Modul1Simulation.c:5102: error: previous declaration of 'tmp_var_18' was here sources/BoilerJMWS3_Test_Modul1Simulation.c:5216: warning: ISO C90 forbids mixed declarations and code sources/BoilerJMWS3_Test_Modul1Simulation.c: In function 'model_ode_initialize': sources/BoilerJMWS3_Test_Modul1Simulation.c:5966: warning: ISO C90 forbids mixed declarations and code sources/BoilerJMWS3_Test_Modul1Simulation.c:5971: error: redeclaration of 'tmp_var_15' with no linkage sources/BoilerJMWS3_Test_Modul1Simulation.c:5966: error: previous declaration of 'tmp_var_15' was here sources/BoilerJMWS3_Test_Modul1Simul