Merge pull request #181 from VectorCamp/bugfix/fix-clang15-compilation-errors

Fix clang 15,16 compilation errors on all platforms, refactor CMake build system

Author: markos

CMakeLists.txt

@@ -29,22 +29,6 @@ matching of regular expressions across streams of data.
 
 Vectorscan is typically used in a DPI library stack, just like Hyperscan.
 
-# Cross Compiling for AArch64
-
-- To cross compile for AArch64, first adjust the variables set in cmake/setenv-arm64-cross.sh.
-  - `export CROSS=<arm-cross-compiler-dir>/bin/aarch64-linux-gnu-`
-  - `export CROSS_SYS=<arm-cross-compiler-system-dir>`
-  - `export BOOST_PATH=<boost-source-dir>`
-- Set the environment variables:
-  - `source cmake/setenv-arm64-cross.sh`
-- Configure Vectorscan:
-  - `mkdir <build-dir-name>`
-  - `cd <build-dir>`
-  - `cmake -DCROSS_COMPILE_AARCH64=1 <hyperscan-source-dir> -DCMAKE_TOOLCHAIN_FILE=<hyperscan-source-dir>/cmake/arm64-cross.cmake`
-- Build Vectorscan:
-  - `make -jT` where T is the number of threads used to compile.
-  - `cmake --build . -- -j T` can also be used instead of make.
-
 # Compiling for SVE
 
 The following cmake variables can be set in order to target Arm's Scalable

README.md

@@ -0,0 +1,91 @@
+if (USE_CPU_NATIVE)
+    # Detect best GNUCC_ARCH to tune for
+    if (CMAKE_COMPILER_IS_GNUCC)
+        message(STATUS "gcc version ${CMAKE_C_COMPILER_VERSION}")
+
+        # If gcc doesn't recognise the host cpu, then mtune=native becomes
+        # generic, which isn't very good in some cases. march=native looks at
+        # cpuid info and then chooses the best microarch it can (and replaces
+        # the flag), so use that for tune.
+
+        set(TUNE_FLAG "mtune")
+        set(GNUCC_TUNE "")
+        message(STATUS "ARCH_FLAG '${ARCH_FLAG}' '${GNUCC_ARCH}', TUNE_FLAG '${TUNE_FLAG}' '${GNUCC_TUNE}' ")
+
+        # arg1 might exist if using ccache
+        string (STRIP "${CMAKE_C_COMPILER_ARG1}" CC_ARG1)
+        set (EXEC_ARGS ${CC_ARG1} -c -Q --help=target -${ARCH_FLAG}=native -${TUNE_FLAG}=native)
+        execute_process(COMMAND ${CMAKE_C_COMPILER} ${EXEC_ARGS}
+            OUTPUT_VARIABLE _GCC_OUTPUT)
+        set(_GCC_OUTPUT_TUNE ${_GCC_OUTPUT})
+        string(FIND "${_GCC_OUTPUT}" "${ARCH_FLAG}=" POS)
+        string(SUBSTRING "${_GCC_OUTPUT}" ${POS} -1 _GCC_OUTPUT)
+        string(REGEX REPLACE "${ARCH_FLAG}=[ \t]*([^ \n]*)[ \n].*" "\\1" GNUCC_ARCH "${_GCC_OUTPUT}")
+
+        string(FIND "${_GCC_OUTPUT_TUNE}" "${TUNE_FLAG}=" POS_TUNE)
+        string(SUBSTRING "${_GCC_OUTPUT_TUNE}" ${POS_TUNE} -1 _GCC_OUTPUT_TUNE)
+        string(REGEX REPLACE "${TUNE_FLAG}=[ \t]*([^ \n]*)[ \n].*" "\\1" GNUCC_TUNE "${_GCC_OUTPUT_TUNE}")
+
+        message(STATUS "ARCH_FLAG '${ARCH_FLAG}' '${GNUCC_ARCH}', TUNE_FLAG '${TUNE_FLAG}' '${GNUCC_TUNE}' ")
+
+        # test the parsed flag
+        set (EXEC_ARGS ${CC_ARG1} -E - -${ARCH_FLAG}=${GNUCC_ARCH} -${TUNE_FLAG}=${GNUCC_TUNE})
+        execute_process(COMMAND ${CMAKE_C_COMPILER} ${EXEC_ARGS}
+            OUTPUT_QUIET ERROR_QUIET
+            INPUT_FILE /dev/null
+            RESULT_VARIABLE GNUCC_TUNE_TEST)
+
+        if (NOT GNUCC_TUNE_TEST EQUAL 0)
+            message(WARNING "Something went wrong determining gcc tune: -mtune=${GNUCC_TUNE} not valid, falling back to -mtune=native")
+            set(GNUCC_TUNE native)
+        else()
+            set(GNUCC_TUNE ${GNUCC_TUNE})
+            message(STATUS "gcc will tune for ${GNUCC_ARCH}, ${GNUCC_TUNE}")
+        endif()
+    elseif (CMAKE_COMPILER_IS_CLANG)
+        if (ARCH_IA32 OR ARCH_X86_64)
+            set(GNUCC_ARCH x86_64_v2)
+            set(TUNE_FLAG generic)
+        elseif(ARCH_AARCH64)
+            if (BUILD_SVE2_BITPERM)
+                set(GNUCC_ARCH ${SVE2_BITPERM_ARCH})
+            elseif (BUILD_SVE2)
+                set(GNUCC_ARCH ${SVE2_ARCH})
+            elseif (BUILD_SVE)
+                set(GNUCC_ARCH ${SVE_ARCH})
+            else ()
+                set(GNUCC_ARCH ${ARMV8_ARCH})
+            endif()
+            set(TUNE_FLAG generic)
+        elseif(ARCH_ARM32)
+            set(GNUCC_ARCH armv7a)
+            set(TUNE_FLAG generic)
+        else()
+            set(GNUCC_ARCH native)
+            set(TUNE_FLAG generic)
+        endif()
+        message(STATUS "clang will tune for ${GNUCC_ARCH}, ${TUNE_FLAG}")
+    endif()
+else()
+    if (ARCH_IA32 OR ARCH_X86_64)
+        set(GNUCC_ARCH native)
+        set(TUNE_FLAG generic)
+    elseif(ARCH_AARCH64)
+        if (BUILD_SVE2_BITPERM)
+            set(GNUCC_ARCH ${SVE2_BITPERM_ARCH})
+        elseif (BUILD_SVE2)
+            set(GNUCC_ARCH ${SVE2_ARCH})
+        elseif (BUILD_SVE)
+            set(GNUCC_ARCH ${SVE_ARCH})
+        else ()
+            set(GNUCC_ARCH ${ARMV8_ARCH})
+        endif()
+        set(TUNE_FLAG generic)
+    elseif(ARCH_ARM32)
+       set(GNUCC_ARCH armv7a)
+       set(TUNE_FLAG generic)
+    else()
+       set(GNUCC_ARCH power9)
+       set(TUNE_FLAG power9)
+    endif()
+endif()