Bash cpuflags (#108)

* added bash-only script to detect cpuid flags based on g++ and/or clang

* wip bash script

* unified arch detection

* wip arch detection

* dynamic executable detection

* removed old regex

* added lscpu detection as first-choice

detect_flags.py

@@ -31,7 +31,6 @@ def get_compile_info_from_compiler(compiler: str, arch_string: str):
         return(re.findall(r' -m((?!no-)[^\s]+)', info))
 
 def get_compile_info_from_lscpu():
-
     if which("lscpu"):
         my_env = os.environ.copy()
         my_env["LANG"] = "en"
@@ -70,16 +69,16 @@ def get_platform():
 if which("lscpu"):
     flags = get_compile_info_from_lscpu()
 else:
-
     arch_string = ""
     if "Apple" in get_platform() or "aarch" in arch:
         arch_string = "-mcpu=native"
     else:
         arch_string = "-march=native"
-    
+
     print("Debug:", arch, get_platform())
     gcc_flags = get_compile_info_from_compiler("g++", "-march=native") if which("g++") else set()
     clang_flags = get_compile_info_from_compiler("clang", arch_string) if which("clang") else set()
-    flags = gcc_flags + clang_flags
-
+    flags.update(gcc_flags)
+    flags.update(clang_flags)
+
 print(' '.join(sorted(flags)))

detect_flags.sh

@@ -0,0 +1,103 @@
+#!/bin/bash
+
+function parse_flags {
+    compiler=$1
+    compilerinfo=$2
+
+    if [ $compiler = "clang" ]; then
+        regex='"-target-feature" "\+([^\"]+)"'
+        if [[ $compilerinfo =~ $regex ]] ; then
+            flag="${BASH_REMATCH[1]}"
+            printf "$flag "
+            # Remove the first regex match and parse recursively
+            parse_flags "$compiler" "${compilerinfo/${BASH_REMATCH[0]}/}"
+        fi
+    elif [ $compiler = "gcc" ]; then
+        regex=' -m([^ ]+)'
+        if [[ $compilerinfo =~ $regex ]] ; then
+            flag="${BASH_REMATCH[1]}"
+            # only print flags that do not start with "no-", since g++ explicitly emits unsupported flags this way.
+            if [[ $flag != no-* ]]; then
+                printf "$flag "
+            fi
+            # Remove the first regex match and parse recursively
+            parse_flags "$compiler" "${compilerinfo/${BASH_REMATCH[0]}/}"
+        fi
+    else
+        echo "Unknown compiler."
+        exit -1
+    fi
+}
+
+lscpu_exe=$(which lscpu)
+if [[ ! -z ${lscpu_exe} && -f $lscpu_exe && -x $lscpu_exe ]]; then 
+    flags=$(eval LANG=en;lscpu|grep -i flags | tr ' ' '\n' | grep -v -E '^Flags:|^$' | sort -d | tr '\n' ' ')
+    echo "$flags"
+else
+    flag_set=()
+
+    gcc_exe=$(which g++)
+    clang_exe=$(which clang)
+
+    if [[ -f $gcc_exe && -x $gcc_exe ]]; then
+        gcc_output=$(eval $gcc_exe -E - -march=native -### 2>&1)
+        parsed_flags=$(parse_flags "gcc" "$gcc_output")
+
+        # Parse whitespace-separated string into an array
+        IFS=' ' read -r -a parsed_array <<< "$parsed_flags"
+        unset IFS
+
+        # Check for every flag if it is already contained in the flag array
+        for flag in "${parsed_array[@]}"
+        do
+            if [[ ! " ${flag_set[*]} " =~ [[:space:]]${flag}[[:space:]] ]]; then
+                flag_set+=("$flag")
+            fi
+        done
+    fi
+
+    if [[ -f $clang_exe && -x $clang_exe ]]; then
+        if [[ "$OSTYPE" == "linux-gnu"* ]];  then
+            if [[ $(uname -i) != aarch* && $(uname -i) != arm*  ]]; then
+                arch_string="-march=native"
+            else
+                arch_string="-mcpu=native"
+            fi
+        elif [[ "$OSTYPE" == "darwin"* ]]; then
+            if [[ $(uname -m) != aarch* && $(uname -m) != arm*  ]]; then
+                arch_string="-march=native"
+            else
+                arch_string="-mcpu=native"
+            fi
+        elif [[ "$OSTYPE" == "cygwin" ]]; then
+            # POSIX compatibility layer and Linux environment emulation for Windows
+            continue
+        elif [[ "$OSTYPE" == "msys" ]]; then
+            # Lightweight shell and GNU utilities compiled for Windows (part of MinGW)
+            continue
+        else
+            echo "Could not detect the current operating system. Aborting."
+            exit 1
+        fi
+
+        clang_output=$(eval $clang_exe -E - $arch_string -### 2>&1)
+        parsed_flags=$(parse_flags "clang" "$clang_output")
+
+        # Parse whitespace-separated string into an array
+        IFS=' ' read -r -a parsed_array <<< "$parsed_flags"
+        unset IFS
+
+        # Check for every flag if it is already contained in the flag array
+        for flag in "${parsed_array[@]}"
+        do
+            if [[ ! " ${flag_set[*]} " =~ [[:space:]]${flag}[[:space:]] ]]; then
+                flag_set+=("$flag")
+            fi
+        done
+    fi
+
+    IFS=$'\n' sorted=($(sort <<<"${flag_set[*]}"))
+    unset IFS
+    printf "%s " "${sorted[@]}"
+    printf "\n"
+fi