Refactor compiler macro detection into a function

Refactored the detection of compiler type and standard version
into a Bash function.

This function determines the compiler in use, extracts the
standard version, and constructs the necessary macro definitions
for static analysis tools. The detected macros are then passed
to cppcheck to ensure proper environment simulation.

- Improve code organization and clarity
- Ensure static analysis tools receive accurate macro definitions
- Support both GCC and Clang detection

Change-Id: I5e37ece6fddb27eeb2eff2dc582aa0f6949db945

Author: willy-liu

scripts/pre-commit.hook

@@ -68,23 +68,25 @@ cppcheck_suppressions() {
   printf "%s" "$out" | sed 's/[[:space:]]*$//'
 }
 
-# Check complier and __STDC_VERSION__
-EXTRA_DEFINES=""
-if command -v gcc >/dev/null 2>&1; then
-  STDC_VERSION=$(gcc -dM -E -xc /dev/null | awk '/__STDC_VERSION__/ {print $3}')
-  EXTRA_DEFINES="-D__GNUC__=1"
-elif command -v clang >/dev/null 2>&1; then
-  STDC_VERSION=$(clang -dM -E -xc /dev/null | awk '/__STDC_VERSION__/ {print $3}')
-  EXTRA_DEFINES="-D__clang__=1"
-else
-  STDC_VERSION=""
-fi
-if [ -n "$STDC_VERSION" ]; then
-  EXTRA_DEFINES+=" -D__STDC__=1 -D__STDC_VERSION__=${STDC_VERSION}"
-fi
+# Check compiler type and __STDC_VERSION__
+get_compiler_macros() {
+    local STDC_VERSION=""
+    local EXTRA_DEFINES=""
+    if command -v gcc >/dev/null 2>&1; then
+        STDC_VERSION=$(gcc -dM -E -xc /dev/null | awk '/__STDC_VERSION__/ {print $3}')
+        EXTRA_DEFINES="-D__GNUC__=1"
+    elif command -v clang >/dev/null 2>&1; then
+        STDC_VERSION=$(clang -dM -E -xc /dev/null | awk '/__STDC_VERSION__/ {print $3}')
+        EXTRA_DEFINES="-D__clang__=1"
+    fi
+    if [ -n "$STDC_VERSION" ]; then
+        EXTRA_DEFINES+=" -D__STDC__=1 -D__STDC_VERSION__=${STDC_VERSION}"
+    fi
+    echo "$EXTRA_DEFINES"
+}
 
 CPPCHECK_OPTS="-I. --enable=all --error-exitcode=1"
-CPPCHECK_OPTS+=" $EXTRA_DEFINES"
+CPPCHECK_OPTS+=" $(get_compiler_macros)"
 CPPCHECK_OPTS+=" --force $(cppcheck_suppressions) $(cppcheck_build_unmatched)"
 CPPCHECK_OPTS+=" --cppcheck-build-dir=.out ."