GitHub Actions: Add libidn2 and tests

PiperOrigin-RevId: 454784764
Change-Id: Id8de7f34a0a5e0236f2fb92841e117cdcf386d2c

.github/workflows/ubuntu-cmake-contrib.yml

@@ -15,6 +15,7 @@ jobs:
           - brotli
           - c-blosc
           - jsonnet
+          - libidn2
           - libraw
           - libtiff
           - lodepng
@@ -63,6 +64,11 @@ jobs:
         echo "CXX=g++-${{matrix.compiler-version}}" >> $GITHUB_ENV
         echo "CC=gcc-${{matrix.compiler-version}}" >> $GITHUB_ENV
 
+    - name: Install extra dependencies for contrib
+      if: matrix.contrib == 'libidn2'
+      run: |
+        sudo apt-get install -qy libidn2-dev libunistring-dev
+
     - name: Create Build Environment
       run: |
         pip3 install absl-py clang

contrib/libidn2/CMakeLists.txt

@@ -16,6 +16,7 @@ cmake_minimum_required(VERSION 3.13..3.22)
 
 project(libidn2-sapi CXX C)
 include(CTest)
+include(GoogleTest)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
@@ -28,22 +29,33 @@ if(NOT TARGET sapi::sapi)
                    EXCLUDE_FROM_ALL)
 endif()
 
-find_package(PkgConfig REQUIRED)
-pkg_check_modules(LIBIDN2 REQUIRED IMPORTED_TARGET libidn2)
+# System libidn2 needs to have the libidn2-dev and libunistring-dev packages
+# installed. We cannot use pkg-config here, as libidn2's config file does not
+# support static linking.
+find_library(libidn2 NAMES libidn2.a idn2)
+find_library(libunistring NAMES libunistring.a unistring)
+
+# Combine libidn2 and its dependency into a single static library
+add_library(idn2_static STATIC
+  "${SAPI_BINARY_DIR}/sapi_force_cxx_linkage.cc"
+)
+target_link_libraries(idn2_static PUBLIC
+  "-Wl,--whole-archive,${libidn2},--no-whole-archive"
+  "-Wl,--whole-archive,${libunistring},--no-whole-archive"
+)
 
 add_sapi_library(libidn2_sapi
   FUNCTIONS idn2_lookup_u8 idn2_register_u8
             idn2_strerror idn2_strerror_name
             idn2_free idn2_to_ascii_8z
             idn2_to_unicode_8z8z
-  INPUTS "${LIBIDN2_INCLUDEDIR}/idn2.h"
-  LIBRARY idn2
+  INPUTS "${libidn2_INCLUDEDIR}/idn2.h"
+  LIBRARY idn2_static
   LIBRARY_NAME IDN2
   NAMESPACE ""
 )
 target_include_directories(libidn2_sapi INTERFACE
   "${PROJECT_BINARY_DIR}"
-  "${SAPI_SOURCE_DIR}"
 )
 
 add_library(libidn2_sapi_wrapper

contrib/libidn2/libidn2_sapi.h

@@ -22,6 +22,7 @@
 
 #include "libidn2_sapi.sapi.h"  // NOLINT(build/include)
 #include "sandboxed_api/util/fileops.h"
+
 class Idn2SapiSandbox : public IDN2Sandbox {
  public:
   std::unique_ptr<sandbox2::Policy> ModifyPolicy(
@@ -32,12 +33,13 @@ class Idn2SapiSandbox : public IDN2Sandbox {
         .AllowStat()
         .AllowWrite()
         .AllowExit()
+        .AllowGetPIDs()
         .AllowSyscalls({
             __NR_futex,
             __NR_close,
             __NR_lseek,
-            __NR_getpid,
         })
+        .BlockSyscallWithErrno(__NR_openat, ENOENT)
         .BuildOrDie();
   }
 };
@@ -62,4 +64,5 @@ class IDN2Lib {
   Idn2SapiSandbox* sandbox_;
   IDN2Api api_;
 };
+
 #endif  // CONTRIB_LIBIDN2_LIBIDN2_SAPI_H_