On Mon, 14 Aug 2023 at 19:44, Dennis Clarke via Gcc-help <gcc-help@xxxxxxxxxxx> wrote: > > > > I think the subject line says it all. > > Looking at : > > https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Standards.html#C-Language > > I see : > > The original ANSI C standard (X3.159-1989) was ratified in 1989 and > published in 1990. This standard was ratified as an ISO standard > (ISO/IEC 9899:1990) later in 1990. There were no technical differences > between these publications, although the sections of the ANSI standard > were renumbered and became clauses in the ISO standard. The ANSI > standard, but not the ISO standard, also came with a Rationale > document. This standard, in both its forms, is commonly known as C89, > or occasionally as C90, from the dates of ratification. To select this > standard in GCC, use one of the options -ansi, -std=c90 or > -std=iso9899:1990; to obtain all the diagnostics required by the > standard, you should also specify -pedantic (or -pedantic-errors if > you want them to be errors rather than warnings). See Options > Controlling C Dialect. > > Errors in the 1990 ISO C standard were corrected in two Technical > Corrigenda published in 1994 and 1996. GCC does not support the > uncorrected version. > > An amendment to the 1990 standard was published in 1995. This > amendment added digraphs and __STDC_VERSION__ to the language, but > otherwise concerned the library. This amendment is commonly known > as AMD1; the amended standard is sometimes known as C94 or C95. To > select this standard in GCC, use the option -std=iso9899:199409 (with, > as for other standard versions, -pedantic to receive all required > diagnostics). > > A new edition of the ISO C standard was published in 1999 as > ISO/IEC 9899:1999, and is commonly known as C99. (While in > development, drafts of this standard version were referred to as C9X.) > GCC has substantially complete support for this standard version; see > https://gcc.gnu.org/c99status.html for details. To select this > standard, use -std=c99 or -std=iso9899:1999. > > Errors in the 1999 ISO C standard were corrected in three Technical > Corrigenda published in 2001, 2004 and 2007. GCC does not support the > uncorrected version. > > A fourth version of the C standard, known as C11, was published > in 2011 as ISO/IEC 9899:2011. (While in development, drafts of this > standard version were referred to as C1X.) GCC has substantially > complete support for this standard, enabled with -std=c11 or > -std=iso9899:2011. A version with corrections integrated was prepared > in 2017 and published in 2018 as ISO/IEC 9899:2018; it is known as C17 > and is supported with -std=c17 or -std=iso9899:2017; the corrections > are also applied with -std=c11, and the only difference between the > options is the value of __STDC_VERSION__. > > Looking also at : > > https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/C-Dialect-Options.html > > There I see : > > -std= > > Determine the language standard. See Language Standards Supported > by GCC, for details of these standard versions. This option is > currently only supported when compiling C or C++. > > With some adjustments or tuning flags such as "-Wpedantic" for some nice > warnings about GNU extensions. As it says at the link below, -pedantic is the same as -Wpedantic. > > HOWEVER I DO NOT see the flags "-pedantic" nor "-pedantic-errors" there. > I see some goodness documented at : > > https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Warning-Options.html > > However that page talks about ANSI C but no mention of something like > the C11 std or others. > > > So the question here is : > > Do the options -pedantic and -pedantic-errors mean anything to > the -std=iso9899:2011 C Language spec? Yes. There are loads of diagnostics which are not issued for C11 without pedantic, e.g. enum E { e = -1u }; This will not warn for C11 unless you use -pedantic e.c:1:14: warning: ISO C restricts enumerator values to range of ‘int’ [-Wpedantic] -pedantic-errors will make that an error.
