Merge pull request #104 from mkinney/add_cppcheck

* Add cppcheck as a github action,
* Some CPP syntax improvements.

Author: mathertel

.github/workflows/cppcheck.yml

@@ -0,0 +1,18 @@
+name: cppcheck-action-test
+on: [push]
+
+jobs:
+  build:
+    name: cppcheck-test
+    runs-on: ubuntu-latest
+    steps:
+
+      - uses: actions/checkout@v2
+
+      - name: Install cppcheck
+        run: |
+          sudo apt-get install cppcheck
+
+      - name: Run cppcheck
+        run: |
+          ./run_cppcheck.sh

run_cppcheck.sh

@@ -0,0 +1 @@
+cppcheck --enable=all --suppressions-list=suppressions.txt --language=c++ -I./src --error-exitcode=2 ./src/*

src/OneButton.h

@@ -46,7 +46,7 @@ class OneButton
    * @param activeLow Set to true when the input level is LOW when the button is pressed, Default is true.
    * @param pullupActive Activate the internal pullup when available. Default is true.
    */
-  OneButton(const int pin, const boolean activeLow = true, const bool pullupActive = true);
+  explicit OneButton(const int pin, const boolean activeLow = true, const bool pullupActive = true);
 
   // ----- Set runtime parameters -----
 
@@ -149,12 +149,12 @@ class OneButton
 
 
 private:
-  int _pin;                         // hardware pin number.
+  int _pin = 0;                     // hardware pin number.
   unsigned int _debounceTicks = 50; // number of ticks for debounce times.
   unsigned int _clickTicks = 400;   // number of msecs before a click is detected.
   unsigned int _pressTicks = 800;   // number of msecs before a long button press is detected
 
-  int _buttonPressed;
+  int _buttonPressed = 0;
 
   // These variables will hold functions acting as event source.
   callbackFunction _clickFunc = NULL;
@@ -175,7 +175,7 @@ class OneButton
 
   callbackFunction _longPressStopFunc = NULL;
   parameterizedCallbackFunction _paramLongPressStopFunc = NULL;
-  void *_longPressStopFuncParam;
+  void *_longPressStopFuncParam = NULL;
 
   callbackFunction _duringLongPressFunc = NULL;
   parameterizedCallbackFunction _paramDuringLongPressFunc = NULL;
@@ -204,9 +204,9 @@ class OneButton
   stateMachine_t _state = OCS_INIT;
   stateMachine_t _lastState = OCS_INIT; // used for debouncing
 
-  unsigned long _startTime; // start of current input change to checking debouncing
-  int _nClicks;             // count the number of clicks with this variable
-  int _maxClicks = 1;       // max number (1, 2, multi=3) of clicks of interest by registration of event functions.
+  unsigned long _startTime = 0; // start of current input change to checking debouncing
+  int _nClicks = 0;             // count the number of clicks with this variable
+  int _maxClicks = 1;           // max number (1, 2, multi=3) of clicks of interest by registration of event functions.
 };
 
 #endif

suppressions.txt

@@ -0,0 +1,6 @@
+// cppcheck suppressions
+unusedFunction
+missingInclude
+
+// this one might be something to look into
+knownConditionTrueFalse