Gcc Error Preprocessor Directive
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-E option, nothing is done except preprocessing. Some of these options make sense only together with -E because they cause the preprocessor output to be unsuitable for actual compilation. -Wp,optionYou can use -Wp,option to bypass the compiler driver and #error c preprocessor pass option directly through to the preprocessor. If option contains commas, it is split
#warning Gcc
into multiple options at the commas. However, many options are modified, translated or interpreted by the compiler driver before being passed c preprocessor message to the preprocessor, and -Wp forcibly bypasses this phase. The preprocessor's direct interface is undocumented and subject to change, so whenever possible you should avoid using -Wp and let the driver handle the options instead. invalid preprocessor command 'warning' -Xpreprocessor optionPass option as an option to the preprocessor. You can use this to supply system-specific preprocessor options that GCC does not recognize. If you want to pass an option that takes an argument, you must use -Xpreprocessor twice, once for the option and once for the argument. -no-integrated-cppPerform preprocessing as a separate pass before compilation. By default, GCC performs preprocessing as an integrated part of input tokenization and parsing.
Gcc #message
If this option is provided, the appropriate language front end (cc1, cc1plus, or cc1obj for C, C++, and Objective-C, respectively) is instead invoked twice, once for preprocessing only and once for actual compilation of the preprocessed input. This option may be useful in conjunction with the -B or -wrapper options to specify an alternate preprocessor or perform additional processing of the program source between normal preprocessing and compilation. -D namePredefine name as a macro, with definition 1. -D name=definitionThe contents of definition are tokenized and processed as if they appeared during translation phase three in a ‘#define’ directive. In particular, the definition will be truncated by embedded newline characters. If you are invoking the preprocessor from a shell or shell-like program you may need to use the shell's quoting syntax to protect characters such as spaces that have a meaning in the shell syntax. If you wish to define a function-like macro on the command line, write its argument list with surrounding parentheses before the equals sign (if any). Parentheses are meaningful to most shells, so you will need to quote the option. With sh and csh, -D'name(args...)=definition' works. -D and -U options are processed in the order they are given on the command line. All -imacro
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#error In C Example
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 generate an error or warning in the C preprocessor? up https://gcc.gnu.org/onlinedocs/gcc/Preprocessor-Options.html vote 19 down vote favorite 1 I have a program that must be compiled only in DEBUG mode. (testing purpose) How can I have the preprocessor prevent compilation in RELEASE mode? c-preprocessor share|improve this question edited Jun 25 at 23:11 phs 7,05722761 asked Feb 8 '10 at 12:29 Eonil 31.1k43203377 add a comment| 7 Answers 7 active oldest votes up vote 34 down vote accepted Place anywhere: #ifndef DEBUG #error http://stackoverflow.com/questions/2221517/how-do-i-generate-an-error-or-warning-in-the-c-preprocessor Only Debug builds are supported #endif share|improve this answer answered Feb 8 '10 at 12:33 Hans Passant 655k819611605 add a comment| up vote 11 down vote C provide a #error statement, and most compilers add a #warning statement. The gcc documentation recommends to quote the message. share|improve this answer edited Nov 17 '15 at 17:28 answered Feb 8 '10 at 12:37 philant 22.9k94890 1 @Antonio Right, there is no [more] recommendation there. I replaced the link with one to gcc doc. –philant Nov 17 '15 at 17:29 add a comment| up vote 4 down vote You can use a error directive for that. The following code will throw an error at compile time if DEBUG is not defined: #ifndef DEBUG #error This is an error message #endif share|improve this answer edited Feb 8 '10 at 23:32 answered Feb 8 '10 at 12:34 Laurent Etiemble 21k44075 Sorry, I mix pragma and error while typing. Corrected in answer. –Laurent Etiemble Feb 8 '10 at 23:32 add a comment| up vote 4 down vote Maybe something more sofisticated, but it is only copy&paste of previous solutions. :-) #ifdef DEBUG #pragma message ( "Debug configuration - OK" ) #elif RELEASE #error "Release configuration - WRONG" #else #error "Unknown configuration
resources Windows Server 2012 resources Programs MSDN subscriptions Overview Benefits Administrators Students Microsoft Imagine Microsoft Student Partners ISV Startups TechRewards Events Community Magazine https://msdn.microsoft.com/en-us/library/c8tk0xsk.aspx Forums Blogs Channel 9 Documentation APIs and reference Dev centers Retired http://www.atmel.com/webdoc/avrassembler/avrassembler.wb_preprocessor.error.html content Samples We’re sorry. The content you requested has been removed. You’ll be auto redirected in 1 second. C/C++ Preprocessor Reference Preprocessor Preprocessor Directives Preprocessor Directives #error Directive #error Directive #error Directive #define Directive #error Directive #if, #elif, #else, and #endif Directives #ifdef #error c and #ifndef Directives #import Directive #include Directive #line Directive Null Directive #undef Directive #using Directive TOC Collapse the table of content Expand the table of content This documentation is archived and is not being maintained. This documentation is archived and is not being maintained. #error Directive (C/C++) Visual Studio 2015 Other Versions Visual Studio gcc error preprocessor 2013 Visual Studio 2012 Visual Studio 2010 Visual Studio 2008 Visual Studio 2005 Visual Studio .NET 2003 The #error directive emits a user-specified error message at compile time and then terminates the compilation.Syntax Copy #errortoken-string RemarksThe error message that this directive emits includes the token-string parameter. The token-string parameter is not subject to macro expansion. This directive is most useful during preprocessing for notifying the developer of a program inconsistency or the violation of a constraint. The following example demonstrates error processing during preprocessing: Copy #if !defined(__cplusplus) #error C++ compiler required. #endif See AlsoPreprocessor Directives Show: Inherited Protected Print Export (0) Print Export (0) Share IN THIS ARTICLE Is this page helpful? Yes No Additional feedback? 1500 characters remaining Submit Skip this Thank you! We appreciate your feedback. Dev centers Windows Office Visual Studio Microsoft Azure More... Learning resources Microsoft Virtual Academy Channel 9 MSDN Magazine Community Forums Blogs Codeplex Support Self support Programs BizSpark (for startups) Microsoft Imagine (for stude
tokens Description #error emits tokens to standard error, and increments the assembler error counter, hereby preventing the program from being successfully assembled. #error is specified in the ANSI C standard. #warning emits tokens to standard error, and increments the assembler warning counter. #warning is not specified in the ANSI C standard, but is commonly implemented in preprocessors such as the GNU C preprocessor. #message emits tokens to standard output, and does not affect assembler error or warning counters. #message is not specified in the ANSI C standard.For all directives, the output will include file name and line number, like normal error and warning messages.tokens is a sequence of preprocessor tokens. Preprocessor macros are expanded except if appearing inside quoted strings (").Example #error "Unsupported part:" __PART_NAME__ PrevUpNextHomeContentsSearchDocumentation HomeAVR AssemblerPrefaceAVR Assembler Known IssuesAVR Assembler Command Line OptionsAssembler sourceAVR Assembler SyntaxAssembler directivesAVR Assembler PreprocessorIntroductionPreprocessor directives#define#undef#ifdef#ifndef#if and #elif#else#endif#error, #warning and #message#include#pragma, general purpose#pragma , AVR part related# (empty directive)OperatorsStringification (#)Concatenation (##)Pre-defined macrosExpressionsInstruction mnemonicsArithmetic and logic instructionsBranch InstructionsData Transfer InstructionsBit and Bit-test InstructionsI/O RegistersInstruction Set Nomenclature:Instructions ADC - Add with Carry ADD - Add without Carry ADIW - Add Immediate to Word AND - Logical AND ANDI - Logical AND with Immediateand ASR - Arithmetic Shift Right BCLR - Bit Clear in SREG BLD - Bit Load from the T Flag in SREG to a Bit in Register. BRBC - Branch if Bit in SREG is Cleared BRBS - Branch if Bit in SREG is Set BRCC - Branch if Carry Cleared BRCS -