test: cover CMake subdirectory consumers

.github/workflows/cmake-tests.yml

@@ -84,6 +84,13 @@ jobs:
         cmake -S "${{ env.SRC_DIR }}/build/cmake" -B build -DBUILD_TESTING=ON -G "${{ matrix.generator }}" -DCMAKE_BUILD_TYPE=Release --install-prefix "${{ runner.temp }}/install"
         cmake --build build --config Release
         cmake --install build --config Release
+    - name: Configure subdirectory consumers
+      run: |
+        cmake -S "${{ env.SRC_DIR }}/build/cmake/tests/consumer" -B consumer-build -G "${{ matrix.generator }}" -DCMAKE_BUILD_TYPE=Release -DCMAKE_COMPILE_WARNING_AS_ERROR=ON
+    - name: Build subdirectory consumers
+      run: cmake --build consumer-build --config Release
+    - name: Test subdirectory consumers
+      run: ctest --test-dir consumer-build -C Release --output-on-failure
 
   # Windows-specific cmake testing with Visual Studio 2022
   # Tests multiple generators and toolchains to ensure broad Windows compatibility

build/cmake/tests/consumer/CMakeLists.txt

@@ -0,0 +1,29 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# You may select, at your option, one of the above-listed licenses.
+
+cmake_minimum_required(VERSION 3.10)
+project(zstd_consumer C CXX)
+
+set(ZSTD_BUILD_PROGRAMS OFF CACHE BOOL "Build command-line programs")
+set(ZSTD_BUILD_TESTS OFF CACHE BOOL "Build zstd's test suite")
+add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/../.." zstd)
+
+enable_testing()
+foreach(kind IN ITEMS static shared)
+    add_executable(consumer_${kind} main.cpp)
+    # Consumers must receive the public headers through the linked target,
+    # without inheriting zstd's directory-scoped include paths.
+    target_link_libraries(consumer_${kind} PRIVATE libzstd_${kind})
+    set_target_properties(consumer_${kind} PROPERTIES CXX_STANDARD 98 CXX_STANDARD_REQUIRED ON)
+    add_test(NAME consumer_${kind} COMMAND consumer_${kind})
+endforeach()
+
+if(WIN32)
+    add_custom_command(TARGET consumer_shared POST_BUILD
+        COMMAND "${CMAKE_COMMAND}" -E copy_if_different
+            "$<TARGET_FILE:libzstd_shared>" "$<TARGET_FILE_DIR:consumer_shared>"
+        VERBATIM)
+endif()

build/cmake/tests/consumer/main.cpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include <zstd.h>
+#include <zstd_errors.h>
+#include <zdict.h>
+#include <string.h>
+
+int main()
+{
+    const char input[] = "CMake subdirectory consumer round trip";
+    char compressed[128];
+    char decompressed[sizeof(input)];
+    const size_t compressedSize = ZSTD_compress(compressed, sizeof(compressed), input, sizeof(input), 1);
+    if (ZSTD_isError(compressedSize)) return 1;
+
+    const size_t decompressedSize = ZSTD_decompress(decompressed, sizeof(decompressed), compressed, compressedSize);
+    if (ZSTD_isError(decompressedSize) || decompressedSize != sizeof(input)) return 1;
+    if (memcmp(input, decompressed, sizeof(input)) != 0) return 1;
+
+    if (ZSTD_getErrorCode(decompressedSize) != ZSTD_error_no_error) return 1;
+    if (ZDICT_getDictID(input, sizeof(input)) != 0) return 1;
+    return 0;
+}