From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2059) id 2DE583858D38; Wed, 21 Feb 2024 08:36:13 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2DE583858D38 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1708504574; bh=2bE6QdN0ovR7OW8Blc/U1tAXWohmRt74rbEHEdHKCbE=; h=From:To:Subject:Date:From; b=iEe76CVgtXxFgMmkSRDW7v5g87kcQ9FNGBvPwXZYTdt/C7e6B8Ihon4Gozw16dZlu yMxbyH35yekjsgHoYloV32DCi99rejRAEBnJgliF8/yFIfV8l68Dwd9j0AnmiimAMT 4Kwf+1WocavZVLNDrRM3Wj9bj8HaQmivPyloHPJQ= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Dimitar Dimitrov To: gcc-cvs@gcc.gnu.org Subject: [gcc r14-9093] pru: Document that arguments are not passed to main with -minrt X-Act-Checkin: gcc X-Git-Author: Dimitar Dimitrov X-Git-Refname: refs/heads/master X-Git-Oldrev: c0a80af4a1d70562dd6671047fe6dd92dcc3f544 X-Git-Newrev: e3dfc150512c331805b8701e9117bd711025800a Message-Id: <20240221083614.2DE583858D38@sourceware.org> Date: Wed, 21 Feb 2024 08:36:13 +0000 (GMT) List-Id: https://gcc.gnu.org/g:e3dfc150512c331805b8701e9117bd711025800a commit r14-9093-ge3dfc150512c331805b8701e9117bd711025800a Author: Dimitar Dimitrov Date: Thu Feb 1 19:19:54 2024 +0200 pru: Document that arguments are not passed to main with -minrt The minimal runtime has been documented from the beginning to break some standard features in order to reduce code size, while keeping the features required by typical firmware programs. Document one more imposed restriction - the main() function must take no arguments. gcc/ChangeLog: * doc/invoke.texi (-minrt): Clarify that main must take no arguments. Signed-off-by: Dimitar Dimitrov Diff: --- gcc/doc/invoke.texi | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index e18886e0ac7b..69020245b256 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -30091,11 +30091,18 @@ These command-line options are defined for PRU target: @table @gcctabopt @opindex minrt @item -minrt -Link with a minimum runtime environment, with no support for static -initializers and constructors. Using this option can significantly reduce -the size of the final ELF binary. Beware that the compiler could still -generate code with static initializers and constructors. It is up to the -programmer to ensure that the source program will not use those features. +Link with a minimum runtime environment. This can significantly reduce +the size of the final ELF binary, but some standard C runtime features +are removed. + +This option disables support for static initializers and constructors. +Beware that the compiler could still generate code with static initializers +and constructors. It is up to the programmer to ensure that the source +program will not use those features. + +The minimal startup code would not pass @code{argc} and @code{argv} arguments +to @code{main}, so the latter must be declared as @code{int main (void)}. +This is already the norm for most firmware projects. @opindex mmcu @item -mmcu=@var{mcu}