Introduce ZLIBNG_ENABLE_TESTS

This patch adds the ability to run zlib-ng test suite against the
original zlib as follows:

    cmake -DZLIB_COMPAT=ON -DZLIBNG_ENABLE_TESTS=OFF .
    make
    LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu make test

The benefit of this is that modifications to the original zlib can be
tested with a more extensive zlib-ng's testsuite, and the assumptions
that the zlib-ng tests make can be validated against the original zlib.

In addition to a number of tests that exercise purely zlib-ng specific
API, there are a few that expect zlib-ng specific behavior from the
original zlib API:

- deflate() (obviously) emits different streams
- zlib-ng's deflatePrime() can take more than 16 bits
- zVersion() returns a different string

Adjust or disable the respective tests for ZLIBNG_ENABLE_TESTS=OFF.

CMakeLists.txt

@@ -76,6 +76,7 @@ endif()
 option(WITH_GZFILEOP "Compile with support for gzFile related functions" ON)
 option(ZLIB_COMPAT "Compile with zlib compatible API" OFF)
 option(ZLIB_ENABLE_TESTS "Build test binaries" ON)
+option(ZLIBNG_ENABLE_TESTS "Test zlib-ng specific API" ON)
 option(WITH_FUZZERS "Build test/fuzz" OFF)
 option(WITH_BENCHMARKS "Build test/benchmarks" OFF)
 option(WITH_BENCHMARK_APPS "Build application benchmarks" OFF)
@@ -1178,6 +1179,7 @@ endif()
 add_feature_info(WITH_GZFILEOP WITH_GZFILEOP "Compile with support for gzFile related functions")
 add_feature_info(ZLIB_COMPAT ZLIB_COMPAT "Compile with zlib compatible API")
 add_feature_info(ZLIB_ENABLE_TESTS ZLIB_ENABLE_TESTS "Build test binaries")
+add_feature_info(ZLIBNG_ENABLE_TESTS ZLIBNG_ENABLE_TESTS "Test zlib-ng specific API")
 add_feature_info(WITH_SANITIZER WITH_SANITIZER "Enable sanitizer support")
 add_feature_info(WITH_FUZZERS WITH_FUZZERS "Build test/fuzz")
 add_feature_info(WITH_BENCHMARKS WITH_BENCHMARKS "Build test/benchmarks")

README.md

@@ -228,6 +228,7 @@ Advanced Build Options
 | WITH_INFLATE_STRICT             |                       | Build with strict inflate distance checking                         | OFF                    |
 | WITH_INFLATE_ALLOW_INVALID_DIST |                       | Build with zero fill for inflate invalid distances                  | OFF                    |
 | INSTALL_UTILS                   |                       | Copy minigzip and minideflate during install                        | OFF                    |
+| ZLIBNG_ENABLE_TESTS             |                       | Test zlib-ng specific API                                           | ON                     |
 
 
 Related Projects

test/CMakeLists.txt

@@ -9,6 +9,10 @@ macro(configure_test_executable target)
     endif()
 endmacro()
 
+if(ZLIBNG_ENABLE_TESTS)
+    add_definitions(-DZLIBNG_ENABLE_TESTS)
+endif()
+
 add_executable(example example.c)
 configure_test_executable(example)
 target_link_libraries(example zlib)
@@ -51,7 +55,10 @@ target_link_libraries(infcover zlib)
 if(NOT DEFINED BUILD_SHARED_LIBS OR BUILD_SHARED_LIBS)
     target_sources(infcover PRIVATE ${PROJECT_SOURCE_DIR}/inftrees.c)
 endif()
-add_test(NAME infcover COMMAND ${CMAKE_CROSSCOMPILING_EMULATOR} $<TARGET_FILE:infcover>)
+# infcover references zng_inflate_table() and struct inflate_state, which are internal to zlib-ng.
+if(ZLIBNG_ENABLE_TESTS)
+    add_test(NAME infcover COMMAND ${CMAKE_CROSSCOMPILING_EMULATOR} $<TARGET_FILE:infcover>)
+endif()
 
 add_executable(makefixed ${PROJECT_SOURCE_DIR}/tools/makefixed.c ${PROJECT_SOURCE_DIR}/inftrees.c)
 configure_test_executable(makefixed)
@@ -135,15 +142,12 @@ else()
             add_subdirectory(${googletest_SOURCE_DIR} ${googletest_BINARY_DIR} EXCLUDE_FROM_ALL)
         endif()
         add_library(GTest::GTest ALIAS gtest)
+        add_library(GTest::Main ALIAS gtest_main)
     endif()
 
     set(TEST_SRCS
-        test_adler32.cc
-        test_aligned_alloc.cc
-        test_compare256.cc
         test_compress.cc
         test_compress_bound.cc
-        test_crc32.cc
         test_cve-2003-0107.cc
         test_deflate_bound.cc
         test_deflate_copy.cc
@@ -158,17 +162,27 @@ else()
         test_deflate_tune.cc
         test_dict.cc
         test_inflate_adler32.cc
-        test_inflate_sync.cc
         test_large_buffers.cc
         test_small_buffers.cc
-        test_version.cc
         )
 
     if(WITH_GZFILEOP)
         list(APPEND TEST_SRCS test_gzio.cc)
     endif()
 
-    add_executable(gtest_zlib test_main.cc ${TEST_SRCS})
+    if(ZLIBNG_ENABLE_TESTS)
+        list(APPEND TEST_SRCS
+             test_adler32.cc             # adler32_neon(), etc
+             test_aligned_alloc.cc       # zng_alloc_aligned()
+             test_compare256.cc          # compare256_neon(), etc
+             test_crc32.cc               # crc32_acle(), etc
+             test_inflate_sync.cc        # expects a certain compressed block layout
+             test_main.cc                # cpu_check_features()
+             test_version.cc             # expects a fixed version string
+             )
+    endif()
+
+    add_executable(gtest_zlib ${TEST_SRCS})
     configure_test_executable(gtest_zlib)
 
     if(WITH_SANITIZER STREQUAL "Memory")
@@ -200,7 +214,14 @@ else()
         target_link_libraries(gtest_zlib external_zlib)
     endif()
 
-    target_link_libraries(gtest_zlib zlibstatic GTest::GTest)
+    if((NOT ZLIBNG_ENABLE_TESTS) AND ZLIB_COMPAT AND (NOT DEFINED BUILD_SHARED_LIBS OR BUILD_SHARED_LIBS))
+        # Link dynamically in order to be able to substitute zlib-ng with zlib.
+        target_link_libraries(gtest_zlib zlib GTest::Main)
+    else()
+        # Link statically in order to test internal zlib-ng functions.
+        target_link_libraries(gtest_zlib zlibstatic)
+    endif()
+    target_link_libraries(gtest_zlib GTest::GTest)
 
     find_package(Threads)
     if(Threads_FOUND)

test/example.c

@@ -15,12 +15,9 @@
 #include <stdarg.h>
 #include <inttypes.h>
 
-#define TESTFILE "foo.gz"
+#include "test_shared_ng.h"
 
-static const char hello[] = "hello, hello!";
+#define TESTFILE "foo.gz"
-/* "hello world" would be more standard, but the repeated "hello"
- * stresses the compression code better, sorry...
- */
 
 static const char dictionary[] = "hello";
 static unsigned long dictId = 0; /* Adler32 value of the dictionary */
@@ -437,8 +434,10 @@ void test_flush(unsigned char *compr, z_size_t *comprLen) {
     *comprLen = (z_size_t)c_stream.total_out;
 }
 
+#ifdef ZLIBNG_ENABLE_TESTS
 /* ===========================================================================
  * Test inflateSync()
+ * We expect a certain compressed block layout, so skip this with the original zlib.
  */
 void test_sync(unsigned char *compr, size_t comprLen, unsigned char *uncompr, size_t uncomprLen) {
     int err;
@@ -474,6 +473,7 @@ void test_sync(unsigned char *compr, size_t comprLen, unsigned char *uncompr, si
 
     printf("after inflateSync(): hel%s\n", (char *)uncompr);
 }
+#endif
 
 /* ===========================================================================
  * Test deflate() with preset dictionary
@@ -785,7 +785,7 @@ void test_deflate_prime(unsigned char *compr, size_t comprLen, unsigned char *un
     err = PREFIX(deflatePrime)(&c_stream, 5, 0x0);
     CHECK_ERR(err, "deflatePrime");
     /* Gzip modified time */
-    err = PREFIX(deflatePrime)(&c_stream, 32, 0x0);
+    err = deflate_prime_32(&c_stream, 0);
     CHECK_ERR(err, "deflatePrime");
     /* Gzip extra flags */
     err = PREFIX(deflatePrime)(&c_stream, 8, 0x0);
@@ -805,10 +805,10 @@ void test_deflate_prime(unsigned char *compr, size_t comprLen, unsigned char *un
 
     /* Gzip uncompressed data crc32 */
     crc = PREFIX(crc32)(0, (const uint8_t *)hello, (uint32_t)len);
-    err = PREFIX(deflatePrime)(&c_stream, 32, crc);
+    err = deflate_prime_32(&c_stream, crc);
     CHECK_ERR(err, "deflatePrime");
     /* Gzip uncompressed data length */
-    err = PREFIX(deflatePrime)(&c_stream, 32, (uint32_t)len);
+    err = deflate_prime_32(&c_stream, (uint32_t)len);
     CHECK_ERR(err, "deflatePrime");
 
     err = PREFIX(deflateEnd)(&c_stream);
@@ -993,7 +993,9 @@ int main(int argc, char *argv[]) {
 #endif
 
     test_flush(compr, &comprLen);
+#ifdef ZLIBNG_ENABLE_TESTS
     test_sync(compr, comprLen, uncompr, uncomprLen);
+#endif
     comprLen = uncomprLen;
 
     test_dict_deflate(compr, comprLen);

test/test_deflate_prime.cc

@@ -12,7 +12,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "test_shared.h"
+#include "test_shared_ng.h"
 
 #include <gtest/gtest.h>
 
@@ -42,7 +42,7 @@ TEST(deflate, prime) {
     err = PREFIX(deflatePrime)(&c_stream, 5, 0x0);
     EXPECT_EQ(err, Z_OK);
     /* Gzip modified time */
-    err = PREFIX(deflatePrime)(&c_stream, 32, 0x0);
+    err = deflate_prime_32(&c_stream, 0x0);
     EXPECT_EQ(err, Z_OK);
     /* Gzip extra flags */
     err = PREFIX(deflatePrime)(&c_stream, 8, 0x0);
@@ -61,10 +61,10 @@ TEST(deflate, prime) {
 
     /* Gzip uncompressed data crc32 */
     crc = PREFIX(crc32)(0, (const uint8_t *)hello, (uint32_t)hello_len);
-    err = PREFIX(deflatePrime)(&c_stream, 32, crc);
+    err = deflate_prime_32(&c_stream, crc);
     EXPECT_EQ(err, Z_OK);
     /* Gzip uncompressed data length */
-    err = PREFIX(deflatePrime)(&c_stream, 32, (uint32_t)hello_len);
+    err = deflate_prime_32(&c_stream, (uint32_t)hello_len);
     EXPECT_EQ(err, Z_OK);
 
     err = PREFIX(deflateEnd)(&c_stream);

test/test_shared.h

@@ -1,2 +1,12 @@
+#ifndef TEST_SHARED_H
+#define TEST_SHARED_H
+
+/* Test definitions that can be used in the original zlib build environment. */
+
+/* "hello world" would be more standard, but the repeated "hello"
+ * stresses the compression code better, sorry...
+ */
 static const char hello[] = "hello, hello!";
 static const int hello_len = sizeof(hello);
+
+#endif

test/test_shared_ng.h

@@ -0,0 +1,23 @@
+#ifndef TEST_SHARED_NG_H
+#define TEST_SHARED_NG_H
+
+#include "test_shared.h"
+
+/* Test definitions that can only be used in the zlib-ng build environment. */
+
+static inline int deflate_prime_32(PREFIX3(stream) *stream, uint32_t value) {
+    int err;
+
+#ifdef ZLIBNG_ENABLE_TESTS
+    err = PREFIX(deflatePrime)(stream, 32, value);
+#else
+    /* zlib's deflatePrime() takes at most 16 bits */
+    err = PREFIX(deflatePrime)(stream, 16, value & 0xffff);
+    if (err != Z_OK) return err;
+    err = PREFIX(deflatePrime)(stream, 16, value >> 16);
+#endif
+
+    return err;
+}
+
+#endif