view auto/cc/gcc @ 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 9eefb38f0005
children
line wrap: on
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


# gcc 2.7.2.3, 2.8.1, 2.95.4, egcs-1.1.2
#     3.0.4, 3.1.1, 3.2.3, 3.3.2, 3.3.3, 3.3.4, 3.4.0, 3.4.2
#     4.0.0, 4.0.1, 4.1.0


NGX_GCC_VER=`$CC -v 2>&1 | grep 'gcc version' 2>&1 \
                         | sed -e 's/^.* version \(.*\)/\1/'`

echo " + gcc version: $NGX_GCC_VER"

have=NGX_COMPILER value="\"gcc $NGX_GCC_VER\"" . auto/define


# Solaris 7's /usr/ccs/bin/as does not support "-pipe"

CC_TEST_FLAGS="-pipe"

ngx_feature="gcc -pipe switch"
ngx_feature_name=
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test=
. auto/feature

CC_TEST_FLAGS=

if [ $ngx_found = yes ]; then
    PIPE="-pipe"
fi


case "$NGX_MACHINE" in

    sun4u | sun4v | sparc | sparc64 )
        # "-mcpu=v9" enables the "casa" assembler instruction
        CFLAGS="$CFLAGS -mcpu=v9"
    ;;

esac


# optimizations

#NGX_GCC_OPT="-O2"
#NGX_GCC_OPT="-Os"
NGX_GCC_OPT="-O"

#CFLAGS="$CFLAGS -fomit-frame-pointer"

case $CPU in
    pentium)
        # optimize for Pentium and Athlon
        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, gcc 3.x
        CPU_OPT="-march=pentium4"
        NGX_CPU_CACHE_LINE=128
    ;;

    athlon)
        # optimize for Athlon, gcc 3.x
        CPU_OPT="-march=athlon"
        NGX_CPU_CACHE_LINE=64
    ;;

    opteron)
        # optimize for Opteron, gcc 3.x
        CPU_OPT="-march=opteron"
        NGX_CPU_CACHE_LINE=64
    ;;

    sparc32)
        # build 32-bit UltraSparc binary
        CPU_OPT="-m32"
        CORE_LINK="$CORE_LINK -m32"
        NGX_CPU_CACHE_LINE=64
    ;;

    sparc64)
        # build 64-bit UltraSparc binary
        CPU_OPT="-m64"
        CORE_LINK="$CORE_LINK -m64"
        NGX_CPU_CACHE_LINE=64
    ;;

    ppc64)
        # build 64-bit PowerPC binary
        CPU_OPT="-m64"
        CPU_OPT="$CPU_OPT -falign-functions=32 -falign-labels=32"
        CPU_OPT="$CPU_OPT -falign-loops=32 -falign-jumps=32"
        CORE_LINK="$CORE_LINK -m64"
        NGX_CPU_CACHE_LINE=128
    ;;

esac

CC_AUX_FLAGS="$CC_AUX_FLAGS $CPU_OPT"

case "$NGX_GCC_VER" in
    2.7*)
        # batch build
        CPU_OPT=
    ;;
esac


CFLAGS="$CFLAGS $PIPE $CPU_OPT"

if [ ".$PCRE_OPT" = "." ]; then
    PCRE_OPT="-O2 -fomit-frame-pointer $PIPE $CPU_OPT"
else
    PCRE_OPT="$PCRE_OPT $PIPE"
fi

if [ ".$ZLIB_OPT" = "." ]; then
    ZLIB_OPT="-O2 -fomit-frame-pointer $PIPE $CPU_OPT"
else
    ZLIB_OPT="$ZLIB_OPT $PIPE"
fi


# warnings

# -W requires at least -O
CFLAGS="$CFLAGS ${NGX_GCC_OPT:--O} -W"

CFLAGS="$CFLAGS -Wall -Wpointer-arith"
#CFLAGS="$CFLAGS -Wconversion"
#CFLAGS="$CFLAGS -Winline"
#CFLAGS="$CFLAGS -Wmissing-prototypes"

case "$NGX_GCC_VER" in
    2.*)
        # we have a lot of the unused function arguments
        CFLAGS="$CFLAGS -Wno-unused"
    ;;

    *)
        # we have a lot of the unused function arguments
        CFLAGS="$CFLAGS -Wno-unused-parameter"
        # 4.2.1 shows the warning in wrong places
        #CFLAGS="$CFLAGS -Wunreachable-code"

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


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

# debug
CFLAGS="$CFLAGS -g"

# DragonFly's gcc3 generates DWARF
#CFLAGS="$CFLAGS -g -gstabs"

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