add make targets to lint the code

Fixes #2818

CONTRIBUTING.md

@@ -1,15 +1,50 @@
-# Style guide
+# Guidelines For Developers
 
-This is style guide for fish contributors. You should use it for any new code
-that you would add to this project and try to format existing code to use this
-style.
+## Lint Free Code
 
-## Formatting
+Automated analysis tools like cppcheck and oclint can help identify bugs. They also help ensure the code has a consistent style and avoids patterns that tend to confuse people.
+
+Ultimately we want lint free code. However, at the moment a lot of cleanup is required to reach that goal. For now simply try to avoid introducing new lint.
+
+To make linting the code easy there are two make targets: `lint` and `lint-all`. The latter does just what the name implies. The former will lint any modified but not committed `*.cpp` files. If there is no uncommitted work it will lint the files in the most recent commit.
+
+To install the lint checkers on Mac OS X using HomeBrew:
+
+```
+brew tap oclint/formulae
+brew install oclint
+brew install cppcheck
+```
+
+To install the lint checkers on Linux distros that use Apt:
+
+```
+sudo apt-get install clang
+sudo apt-get install oclint
+sudo apt-get install cppcheck
+```
+
+## Fish Script Style Guide
+
+Fish scripts such as those in the *share/functions* and *tests* directories should be formatted using the `fish_indent` command.
+
+Function names should be all lowercase with undescores separating words. Private functions should begin with an underscore. The first word should be `fish` if the function is unique to fish.
+
+The first word of global variable names should generally be `fish` for public vars or `_fish` for private vars to minimize the possibility of name clashes with user defined vars.
+
+## C++ Style Guide
+
+1. The `clang-format` command is authoritative with respect to indentation, whitespace around operators, etc. **Note**: this rule should be ignored at this time. A subsequent commit will add the necessary config file and make targets. After the happens the code will be cleaned up and this rule will become mandatory.
+
+1. All names in code should be `small_snake_case`. No Hungarian notation is used. Classes and structs names should be followed by `_t`.
 
 1. fish uses the Allman/BSD style of indentation.
-2. Indent with spaces, not tabs.
-3. Use 4 spaces per indent (unless needed like `Makefile`).
-4. Opening curly bracket is on the following line:
+
+1. Indent with spaces, not tabs.
+
+1. Use 4 spaces per indent.
+
+1. Opening curly bracket is on the following line:
 
         // ✔:
         struct name
@@ -32,7 +67,7 @@ style.
           // code
         }
 
-5. Put space after `if`, `while` and `for` before conditions.
+1. Put space after `if`, `while` and `for` before conditions.
 
         // ✔:
         if () {}
@@ -40,7 +75,7 @@ style.
         // ✗:
         if() {}
 
-6. Put spaces before and after operators excluding increment and decrement;
+1. Put spaces before and after operators excluding increment and decrement;
 
         // ✔:
         int a = 1 + 2 * 3;
@@ -50,7 +85,7 @@ style.
         int a=1+2*3;
         a ++;
 
-7. Never put spaces between function name and parameters list.
+1. Never put spaces between function name and parameters list.
 
         // ✔:
         func(args);
@@ -58,8 +93,9 @@ style.
         // ✗:
         func (args);
 
-8. Never put spaces after `(` and before `)`.
-9. Always put space after comma and semicolon.
+1. Never put spaces after `(` and before `)`.
+
+1. Always put space after comma and semicolon.
 
         // ✔:
         func(arg1, arg2);
@@ -70,36 +106,3 @@ style.
         func(arg1,arg2);
 
         for (int i = 0;i<LENGTH;i++) {}
-
-## Documentation
-
-Document your code using [Doxygen][dox].
-
-1. Documentation comment should use double star notation or tripple slash:
-
-        // ✔:
-        /// Some var
-        int var;
-
-        /**
-         * Some func
-         */
-        void func();
-
-2. Use slash as tag mark:
-
-        // ✔:
-
-        /**
-         * \param a an integer argument.
-         * \param s a constant character pointer.
-         * \return The results
-         */
-        int foo(int a, const char *s);
-
-## Naming
-
-All names in code should be `small_snake_case`. No Hungarian notation is used.
-Classes and structs names should be followed by `_t`.
-
-[dox]: http://www.stack.nl/~dimitri/doxygen/ "Doxygen homepage"