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Re: Build issue with postgresql 17 undefined reference to `pg_encoding_to_char' and `pg_char_to_encoding' - Mailing list pgsql-hackers

From Mikael Sand
Subject Re: Build issue with postgresql 17 undefined reference to `pg_encoding_to_char' and `pg_char_to_encoding'
Date
Msg-id CAAwAxZeLAAjs69jP0ECqe-EFwmvBsi61QJQFXtWKvSBBr-UGmw@mail.gmail.com
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In response to Re: Build issue with postgresql 17 undefined reference to `pg_encoding_to_char' and `pg_char_to_encoding'  (Mikael Sand <msand@seaber.io>)
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Tom

Would this be an acceptable patch?

Subject: [PATCH] Fix static build
---
Index: src/Makefile.shlib
<+>UTF-8
===================================================================
diff --git a/src/Makefile.shlib b/src/Makefile.shlib
--- a/src/Makefile.shlib (revision fd64ed60b62697984bb69a09a3ae19fbe2905eb6)
+++ b/src/Makefile.shlib (date 1728590127913)
@@ -354,7 +354,7 @@
 # those that point inside the build or source tree.  Use sort to
 # remove duplicates.  Also record the -l flags necessary for static
 # linking, but not those already covered by Requires.private.
- echo 'Libs.private: $(sort $(filter-out -L.% -L$(top_srcdir)/%,$(filter -L%,$(LDFLAGS) $(SHLIB_LINK)))) $(filter-out $(PKG_CONFIG_REQUIRES_PRIVATE:lib%=-l%),$(filter -l%,$(SHLIB_LINK_INTERNAL:%_shlib=%) $(SHLIB_LINK)))' >>$@
+ echo 'Libs.private: $(sort $(filter-out -L.% -L$(top_srcdir)/%,$(filter -L%,$(LDFLAGS) $(SHLIB_LINK)))) $(filter-out $(PKG_CONFIG_REQUIRES_PRIVATE:lib%=-l%),$(filter -l%,$(SHLIB_LINK_INTERNAL) $(SHLIB_LINK)))' >>$@
 
 
 ##

Br Mikael

On Thu, Oct 10, 2024 at 9:08 PM Mikael Sand <msand@seaber.io> wrote:
Aleksander, do you have something against static linking or am I reading you wrong?
I've seen this sentiment in several places but never understood why anyone would hold this position. Could you elaborate?

At least for executables intended to be run in production inside containers, they usually run in isolation, what other executables could they share libraries with?
Should we leave performance on the table, given the energy and resource requirements it implies?

Certainly, for libraries intended to be distributed in e.g. Linux distributions and be depended on in end-user executables, it makes sense to have shared libraries and simplify mitigating security issues.

It appears to me that there are many cases where static linking and link time optimization would be more appropriate than dynamic.
When the executables never have a chance to share libraries with any other process and are rebuilt whenever a new version is deployed what benefits does dynamic linking provide over static + lto?

I expect I'm missing something crucial, but I have spent some time trying to understand this issue deeper, and still find myself mystified.
Please enlighten me.

Br Mikael

On Thu, Oct 10, 2024 at 8:29 PM Mikael Sand <msand@seaber.io> wrote:
Just for reference in case anyone else who utilizes static linking for any reason hits upon this issue, here is a working Dockerfile for libpq / postgresql 17

FROM postgres:17.0-alpine3.20 AS builder
USER root
WORKDIR /app
RUN apk update && apk add --no-cache --update-cache \
    openssl-libs-static \
    libevent-static \
    libxml2-static \
    libedit-static \
    libxslt-static \
    sqlite-static \
    openldap-dev \
    libxslt-dev \
    libxml2-dev \
    libedit-dev \
    openssl-dev \
    zstd-static \
    zlib-static \
    lz4-static \
    e2fsprogs \
    keyutils \
    zstd-dev \
    zlib-dev \
    gdbm-dev \
    clang17 \
    lz4-dev \
    libldap \
    bison \
    curl \
    perl \
    make

COPY <<EOF ./main.cpp
#include<libpq-fe.h>
int main(){return PQconnectdb("")==NULL;}
EOF

ARG KRB5=1.21.3
ARG KRB5MAJMIN=1.21
RUN curl -L https://kerberos.org/dist/krb5/$KRB5MAJMIN/krb5-$KRB5.tar.gz | tar xzf -
RUN cd krb5-$KRB5/src && \
    ./configure && make && make install && \
    ./configure --disable-shared --enable-static && make && make install

ARG SASL=2.1.28
RUN curl -L https://github.com/cyrusimap/cyrus-sasl/releases/download/cyrus-sasl-$SASL/cyrus-sasl-$SASL.tar.gz | tar xzf -
RUN cd cyrus-sasl-$SASL && ./configure --enable-static && make && make install

RUN clang++ -static -o main main.cpp \
    -L/usr/local/lib -lpq -lpgcommon_shlib -lpgport_shlib \
    -lldap -lsasl2 -lssl -lcrypto -llber \
    -lgssapi_krb5 \
    -lkrb5 -lk5crypto -lcom_err -lkrb5support \
    -lgdbm

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