Tune up new Makefile syntax

.github/workflows/wide_integer.yml

@@ -148,12 +148,12 @@ jobs:
       - name: gcc-clang-native
         run: |
           grep BOOST_VERSION ../boost-root/boost/version.hpp
-          echo "compile ./wide_integer.exe"
+          echo "compile and link to ./wide_integer via Makefile"
           ${{ matrix.compiler }} -v
-          ${{ matrix.compiler }} -finline-functions -m64 -O3 -Werror -Wall -Wextra -Wpedantic -Wconversion -Wsign-conversion -Wshadow -Wundef -Wunused-parameter -Wuninitialized -Wunreachable-code -Winit-self -Wzero-as-null-pointer-constant -std=${{ matrix.standard }} -DWIDE_INTEGER_HAS_LIMB_TYPE_UINT64 -I. -I../boost-root -pthread -lpthread  test/test.cpp test/test_uintwide_t_boost_backend.cpp test/test_uintwide_t_edge_cases.cpp test/test_uintwide_t_examples.cpp test/test_uintwide_t_float_convert.cpp test/test_uintwide_t_int_convert.cpp test/test_uintwide_t_n_base.cpp test/test_uintwide_t_n_binary_ops_base.cpp test/test_uintwide_t_spot_values.cpp examples/example000_numeric_limits.cpp examples/example000a_builtin_convert.cpp examples/example001_mul_div.cpp examples/example001a_div_mod.cpp examples/example002_shl_shr.cpp examples/example003_sqrt.cpp examples/example003a_cbrt.cpp examples/example004_rootk_pow.cpp examples/example005_powm.cpp examples/example005a_pow_factors_of_p99.cpp examples/example006_gcd.cpp examples/example007_random_generator.cpp examples/example008_miller_rabin_prime.cpp examples/example008a_miller_rabin_prime.cpp examples/example009_timed_mul.cpp examples/example009a_timed_mul_4_by_4.cpp examples/example009b_timed_mul_8_by_8.cpp examples/example010_uint48_t.cpp examples/example011_uint24_t.cpp examples/example012_rsa_crypto.cpp examples/example013_ecdsa_sign_verify.cpp examples/example014_pi_spigot_wide.cpp -o wide_integer.exe
-          echo "ls ./wide_integer.exe"
-          ls -la ./wide_integer.exe
-          ./wide_integer.exe
+          make MY_STD=${{ matrix.standard }} MY_CC=${{ matrix.compiler }} MY_BOOST_ROOT=../boost-root all
+          echo "ls ./wide_integer"
+          ls -la ./wide_integer
+          ./wide_integer
   gcc-clang-native-limb_type_uint64_t:
     runs-on: ubuntu-latest
     defaults:

Makefile

@@ -111,7 +111,7 @@ endif
 
 
 compile_and_link :
-	$(ECHO) +++ compiling and linking to wide_integer
-	$(ECHO)
-	$(CC) $(CPPFLAGS) $(C_INCLUDES) $(LDFLAGS) $(FILES_SRC) -o wide_integer
-	$(ECHO)
+	@-$(ECHO) +++ compiling and linking to wide_integer
+	@-$(ECHO)
+	@-$(CC) $(CPPFLAGS) $(C_INCLUDES) $(LDFLAGS) $(FILES_SRC) -o wide_integer
+	@-$(ECHO)

README.md

@@ -313,6 +313,19 @@ examples/example014_pi_spigot_wide.cpp      \
 -o wide_integer.exe
 ```
 
+### Build on the *nix command line via GNUmake
+
+There is straightforward GNUmake support via [Makefile](./Makefile).
+The Makefile supports various command-line options that allow tuning the compiler,
+language standard, Boost's root directory, etc.
+
+A sample command line for building the executable `wide_integer`
+with the Makefile is shown below.
+
+```sh
+make MY_CC=clang++ MY_STD=c++23 MY_BOOST_ROOT=../boost-root all
+```
+
 ## Testing, CI and Quality Checks
 
 ### Testing