protocolbuffers/protobuf

Define cmake target as PIC if BUILD_SHARED_LIBS

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#10,828 opened on Oct 27, 2022

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c++cmakehelp wanted

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Description

What language does this apply to? Generated C/C++ code and the specific cmake target.

Describe the problem you are trying to solve. When I link to the generated cmake target and set the BUILD_SHARED_LIBS variable globally I get linker errors because the protobuf created code is not relocateable.

Describe the solution you'd like In my user code I use something like the following:

# ensure relocateable code
if (BUILD_SHARED_LIBS)
  set_property(TARGET ${PROTO_TARGET} PROPERTY POSITION_INDEPENDENT_CODE TRUE)
endif ()

But this could be integrated in the cmake part of this project directly.

Describe alternatives you've considered It's not a big problem. But may be helpful for people that do not have that much cmake experience.

Additional context Nothing.

Contributor guide

Research direction
Locate the cmake targets that define the protobuf generated library and add a property setting for POSITION INDEPENDENT CODE when BUILD SHARED LIBS is true. This is typically done in the CMakeLists.txt files in the `src` or `cmake` directories.
Tech stack
cpp
Domain
build system
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
1
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
cmake
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
80