CI: Find protobuf and pass it to cmake on macOS (p4lang#3896)

* Find protbuf and pass it to cmake on macOS * CI: Don't allow static protobuf on macOS Co-developed-by: Vladimir Still <git@vstill.eu> Co-developed-by: David Bolvansky <david.bolvansky@intel.com> Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org> * Add note about Protobuf & CMake on macOS in README Co-developed-by: Vladimir Still <git@vstill.eu> Co-developed-by: David Bolvansky <david.bolvansky@intel.com> Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org> * Fix typo, add link to homebrew PR --------- Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org> Co-authored-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
kamleshbhalui · Feb 16, 2023 · 341079a · 341079a
1 parent daa55c8
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diff --git a/.github/workflows/ci-test.yml b/.github/workflows/ci-test.yml
@@ -140,7 +140,7 @@ jobs:
     - name: Run tests (Ubuntu 18.04)
       run: |
         sudo -E docker run --privileged -w /p4c/build -e $CTEST_PARALLEL_LEVEL p4c ctest --output-on-failure --schedule-random
-  
+
   # Build and test p4c on Fedora.
   test-fedora-linux:
     strategy:
@@ -205,8 +205,19 @@ jobs:
            echo "/usr/local/opt/bison/bin" >> $GITHUB_PATH
 
     - name: Build (MacOS)
+      # for some reason, brew does not install protobuf in a way cmake would be
+      # able to find it. Also, the library needs to be specified manually in
+      # order for the compiler to be correctly linked with protobuf.
+      # Also, there are no static protobuf libs in homebrew.
+      # See also https://github.com/Homebrew/homebrew-core/pull/122277
       run: |
-          ./bootstrap.sh -DENABLE_GC=ON -DCMAKE_BUILD_TYPE=RELEASE -DENABLE_UNIFIED_COMPILATION=ON && cd build && make -j2
+          PROTOBUF=`brew --prefix --installed protobuf`
+          ./bootstrap.sh -DENABLE_GC=ON -DCMAKE_BUILD_TYPE=RELEASE \
+              -DENABLE_UNIFIED_COMPILATION=ON \
+              -DProtobuf_INCLUDE_DIR=$PROTOBUF/include \
+              -DProtobuf_LIBRARY=$PROTOBUF/lib/libprotobuf.dylib \
+              -DENABLE_PROTOBUF_STATIC=OFF
+          make -Cbuild -j2
 
     - name: Run tests (MacOS)
       # TODO: Renable gtest. Unit tests currently fail on MacOS.

diff --git a/README.md b/README.md
@@ -24,7 +24,7 @@ The code contains seven sample backends:
   https://doc.dpdk.org/guides/rel_notes/release_20_11.html,
 * p4c-ebpf: can be used to generate C code which can be compiled to [eBPF](https://en.wikipedia.org/wiki/Berkeley_Packet_Filter)
   and then loaded in the Linux kernel. The eBPF backend currently implements two architecture models:
-  [ebpf_model.p4 for packet filtering](./backends/ebpf/README.md) and [the fully-featured PSA (Portable Switch Architecture) model](./backends/ebpf/psa/README.md). 
+  [ebpf_model.p4 for packet filtering](./backends/ebpf/README.md) and [the fully-featured PSA (Portable Switch Architecture) model](./backends/ebpf/psa/README.md).
 * p4test: a source-to-source P4 translator which can be used for
   testing, learning compiler internals and debugging,
 * p4c-graphs: can be used to generate visual representations of a P4 program;
@@ -346,6 +346,18 @@ Installing on macOS:
   out the newest tag in the 3.0 series (`v3.0.2` as of this writing) before you
   build.
 
+  The `protobuf` formula requires the following CMake variables to be set,
+  otherwise CMake does not find the libraries or fails in linking. It is likely
+  that manually installed Protobuf will require similar treatment.
+
+  ```
+  PB_PREFIX="$(brew --prefix --installed protobuf)"
+  ./bootstrap.sh \
+    -DProtobuf_INCLUDE_DIR="${PB_PREFIX}/include/" \
+    -DProtobuf_LIBRARY="${PB_PREFIX}/lib/libprotobuf.dylib" \
+    -DENABLE_PROTOBUF_STATIC=OFF
+  ```
+
 ## Garbage collector
 
 P4c relies on [BDW garbage collector](https://github.com/ivmai/bdwgc)