view auto/cc/clang @ 9300:5be23505292b

SSI: fixed incorrect or duplicate stub output. Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set if there are data in the first buffer sent in the subrequest. As a result, following the change mentioned this flag cannot be used to prevent duplicate ngx_http_ssi_stub_output() calls, since it is not set if there was already some output, but the first buffer was empty. Still, when there are multiple subrequests, even an empty subrequest response might be delayed by the postpone filter, leading to a second call of ngx_http_ssi_stub_output() during finalization from ngx_http_writer() the subreqest buffers are released by the postpone filter. Since r->request_output is not set after the first call, this resulted in duplicate stub output. Additionally, checking only the first buffer might be wrong in some unusual cases. For example, the first buffer might be empty if $r->flush() is called before printing any data in the embedded Perl module. Depending on the postpone_output value and corresponding sizes, this issue can result in either duplicate or unexpected stub output, or "zero size buf in writer" alerts. Following 8124:f5515e727656 (1.23.4), it became slightly easier to reproduce the issue, as empty static files and empty cache items now result in a response with an empty buffer. Before the change, an empty proxied response can be used to reproduce the issue. Fix is check all buffers and set r->request_output if any non-empty buffers are sent. This ensures that all unusual cases of non-empty responses are covered, and also that r->request_output will be set after the first stub output, preventing duplicate output. Reported by Jan Gassen.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 04 Jul 2024 17:41:28 +0300
parents ceab908790c4
children
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# Copyright (C) Nginx, Inc.


# clang


NGX_CLANG_VER=`$CC -v 2>&1 | grep 'version' 2>&1 \
                           | sed -n -e 's/^.*clang version \(.*\)/\1/p' \
                                    -e 's/^.*LLVM version \(.*\)/\1/p'`

echo " + clang version: $NGX_CLANG_VER"

have=NGX_COMPILER value="\"clang $NGX_CLANG_VER\"" . auto/define


CC_TEST_FLAGS="-pipe"


# optimizations

#NGX_CLANG_OPT="-O2"
#NGX_CLANG_OPT="-Oz"
NGX_CLANG_OPT="-O"

case $CPU in
    pentium)
        # optimize for Pentium
        CPU_OPT="-march=pentium"
        NGX_CPU_CACHE_LINE=32
    ;;

    pentiumpro | pentium3)
        # optimize for Pentium Pro, Pentium II and Pentium III
        CPU_OPT="-march=pentiumpro"
        NGX_CPU_CACHE_LINE=32
    ;;

    pentium4)
        # optimize for Pentium 4
        CPU_OPT="-march=pentium4"
        NGX_CPU_CACHE_LINE=128
    ;;

    athlon)
        # optimize for Athlon
        CPU_OPT="-march=athlon"
        NGX_CPU_CACHE_LINE=64
    ;;

    opteron)
        # optimize for Opteron
        CPU_OPT="-march=opteron"
        NGX_CPU_CACHE_LINE=64
    ;;

esac

CC_AUX_FLAGS="$CC_AUX_FLAGS $CPU_OPT"


CFLAGS="$CFLAGS -pipe $CPU_OPT"

if [ ".$PCRE_OPT" = "." ]; then
    PCRE_OPT="-O2 -pipe $CPU_OPT"
else
    PCRE_OPT="$PCRE_OPT -pipe"
fi

if [ ".$ZLIB_OPT" = "." ]; then
    ZLIB_OPT="-O2 -pipe $CPU_OPT"
else
    ZLIB_OPT="$ZLIB_OPT -pipe"
fi


# warnings

CFLAGS="$CFLAGS $NGX_CLANG_OPT -Wall -Wextra -Wpointer-arith"
CFLAGS="$CFLAGS -Wconditional-uninitialized"
#CFLAGS="$CFLAGS -Wmissing-prototypes"

# we have a lot of unused function arguments
CFLAGS="$CFLAGS -Wno-unused-parameter"

# deprecated system OpenSSL library on OS X
if [ "$NGX_SYSTEM" = "Darwin" ]; then
    CFLAGS="$CFLAGS -Wno-deprecated-declarations"
fi

# stop on warning
CFLAGS="$CFLAGS -Werror"

# debug
CFLAGS="$CFLAGS -g"

if [ ".$CPP" = "." ]; then
    CPP="$CC -E"
fi