C Error Missing Prototype
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 about Stack Overflow the company Business Learn more about hiring developers or posting ads 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 Explanation of missing prototype error message for custom getln function in C up vote 2 down vote favorite #include
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 about Stack Overflow the company Business Learn more about hiring developers or posting ads 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 How do I get missing prototype warnings http://stackoverflow.com/questions/31209591/explanation-of-missing-prototype-error-message-for-custom-getln-function-in-c from g++? up vote 6 down vote favorite I currently have a project that uses g++ to compile it's code. I'm in the process of cleaning up the code, and I'd like to ensure that all functions have prototypes, to ensure things like const char * are correctly handled. Unfortunately, g++ complains when I try to specify -Wmissing-prototypes: g++ -Wmissing-prototypes -Wall -Werror -c foo.cpp cc1plus: warning: http://stackoverflow.com/questions/2389169/how-do-i-get-missing-prototype-warnings-from-g command line option "-Wmissing-prototypes" is valid for Ada/C/ObjC but not for C++ Can someone tell me: 1) Why does gcc this isn't valid? Is this a bug in gcc? 2) Is there a way to turn on this warning? EDIT: Here's a cut and paste example: cat > foo.cpp < 30 Days In the Last 90 Days In the Last 6 Months Technical Support Overview Search Contact Assistance Request Feedback Support Resources Support Knowledgebase Article Index Top 10 http://www.keil.com/support/docs/884.htm Articles Product Manuals Application Notes Downloads Product Updates Discussion Forum Books Product Information Software https://bytes.com/topic/c/answers/695019-missing-prototype & Hardware Products ARM Development ToolsC166 Development ToolsC51 Development ToolsC251 Development ToolsDebug AdaptersEvaluation Boards Product Brochures Newsletters Home/Technical Support C51: WARNING 206 (MISSING FUNCTION PROTOTYPE) Information in this article applies to: C51 Version 5.50 QUESTION While compiling my C source file, the compiler reported the following diagnostic: WARNING 206: MISSING FUNCTION PROTOTYPE ANSWER The c error called function is unknown because no prototype declaration exists. Calls to unknown functions risk that the number of parameters may not correspond to the actual requirements. If this is the case, the function is called incorrectly. The compiler has no way to check for missing or excessive parameters and their types. Include prototypes of the functions used in your program. Prototypes must be specified before the functions are actually c error missing called. The definition of a function automatically produces a prototype. MORE INFORMATION Refer to Warning C206 in the Cx51 User's Guide. Last Reviewed: Friday, July 15, 2005 Did this article provide the answer you needed? 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Accept and hide this message Acquisition of ARM Holdings plc. by SoftBank Group Corp. We are pleased to inform you that on 5 tips & solutions from a community of 418,461 IT Pros & Developers. It's quick & easy. Missing Prototype 100+ P: 153 kreagan I am out of ideas for this problem. I have a .c file name AAT which includes TestUtilities.h. Within TestUtilities, I have a method named measureResistance() that AAT calls throught the code. TestUtilities also has other functions which AAT calls too. However, I get the error "Missing Prototype" for only measureResistance() calls. Yes, I checked the the spelling in the AAT.c, TestUtilities.h, and TestUtilities.c files. The spelling and parameters are correct throught the three files. Yes, I did include the .h file in the project. Again, there are no other functions which generate this error within TestUtilities. ~Kat Aug 19 '07 #1 Post Reply Share this Question 6 Replies Expert Mod 5K+ P: 8,904 weaknessforcats Locate the function definition for measureResistance and copy the first line to the prototype in TestUtilities.h. Add a semi-colon and rebuild. Often this error occurs not becuse the function name was incorrect but that the arguments or return type didn't match. If that doesn't do it, post that section of TestUtilities.h and AAT.c where a call is made and I'll look at it. Aug 19 '07 #2 reply 100+ P: 153 kreagan Thanks for the help and quick response. FYI, This is C, not C++. If I had different number of arguements, the compiler would state: "Insufficient number of arguement ...." or if the arguements were of the wrong type, the error would say, "Expecting TYPE A found TYPE B". From my understanding, method overloading doesn't exist in C. AAT.C #include "TestUtilities.h" ... // Measure Resistance. Result should be 1700 ohms +/- 10% status = measureResistance(); if ( status == 0 ){ status = testResistance( test_resistance, percent_error); } .... TestUtilities.C int measureResistance(){ status = 0; status = APP_DMM_Measure("resistance", &resistance ); if (status !=0){ EL_logErrorData(status, "Error Measuring Resistance"); } return status; } TestUtilities.h .... int measureResistance(); int testResistance( int test_resistance, double percent_error); .... Aug 19 '07 #3 reply Expert Mod 5K+ P: 8,904 weaknessforcats This compiles as C using Visual Studio.NET 2005. I only had to change