6.8 #error, #warning, and #message
Syntax
#error tokens
#warning tokens
#message 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__