Handle flawfinder severity level (#1400)

* Handle flawfinder severity level
* Reverted code allowing Flawfinder to piggyback off of gcc's format handler
* Gave Flawfinder its own format handler and made requested changes.

ale_linters/c/flawfinder.vim

@@ -4,6 +4,7 @@
 call ale#Set('c_flawfinder_executable', 'flawfinder')
 call ale#Set('c_flawfinder_options', '')
 call ale#Set('c_flawfinder_minlevel', 1)
+call ale#Set('c_flawfinder_error_severity', 6)
 
 function! ale_linters#c#flawfinder#GetExecutable(buffer) abort
    return ale#Var(a:buffer, 'c_flawfinder_executable')
@@ -26,5 +27,5 @@ call ale#linter#Define('c', {
 \  'output_stream': 'stdout',
 \  'executable_callback': 'ale_linters#c#flawfinder#GetExecutable',
 \  'command_callback': 'ale_linters#c#flawfinder#GetCommand',
-\  'callback': 'ale#handlers#gcc#HandleGCCFormat',
+\  'callback': 'ale#handlers#flawfinder#HandleFlawfinderFormat',
 \})

ale_linters/cpp/flawfinder.vim

@@ -26,5 +26,5 @@ call ale#linter#Define('cpp', {
 \  'output_stream': 'stdout',
 \  'executable_callback': 'ale_linters#cpp#flawfinder#GetExecutable',
 \  'command_callback': 'ale_linters#cpp#flawfinder#GetCommand',
-\  'callback': 'ale#handlers#gcc#HandleGCCFormat',
+\  'callback': 'ale#handlers#flawfinder#HandleFlawfinderFormat',
 \})

autoload/ale/handlers/flawfinder.vim

@@ -0,0 +1,47 @@
+" Author: Christian Gibbons <cgibbons@gmu.edu>
+" Description: This file defines a handler function that should work for the
+" flawfinder format with the -CDQS flags.
+
+" Swiped this function from the GCC handler. Not sure if needed, but doesn't
+" hurt to have it.
+function! s:RemoveUnicodeQuotes(text) abort
+    let l:text = a:text
+    let l:text = substitute(l:text, '[`´‘’]', '''', 'g')
+    let l:text = substitute(l:text, '\v\\u2018([^\\]+)\\u2019', '''\1''', 'g')
+    let l:text = substitute(l:text, '[“”]', '"', 'g')
+
+    return l:text
+endfunction
+
+function! ale#handlers#flawfinder#HandleFlawfinderFormat(buffer, lines) abort
+    " Look for lines like the following.
+    "
+    " <stdin>:12:4:  [2] (buffer) char:Statically-sized arrays can be improperly restricted, leading to potential overflows or other issues (CWE-119!/CWE-120).  Perform bounds checking, use functions that limit length, or ensure that the size is larger than the maximum possible length.
+    " <stdin>:31:4:  [1] (buffer) strncpy:Easily used incorrectly; doesn't always \0-terminate or check for invalid pointers [MS-banned] (CWE-120).
+    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):(\d+)?:? ( \[[0-5]\] [^:]+):(.+)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        " Use severity level to determine if it should be considered a warning
+        " or error.
+        let l:severity = str2nr(matchstr(split(l:match[4])[0], '[0-5]'))
+
+        let l:item = {
+        \   'lnum': str2nr(l:match[2]),
+        \   'col': str2nr(l:match[3]),
+        \   'type': (l:severity < ale#Var(a:buffer, 'c_flawfinder_error_severity'))
+            \   ? 'W' : 'E',
+        \   'text': s:RemoveUnicodeQuotes(join(split(l:match[4])[1:]) . ': ' . l:match[5]),
+        \}
+
+        " If the filename is something like <stdin>, <nofile> or -, then
+        " this is an error for the file we checked.
+        if l:match[1] isnot# '-' && l:match[1][0] isnot# '<'
+            let l:item['filename'] = l:match[1]
+        endif
+
+        call add(l:output, l:item)
+    endfor
+
+    return l:output
+endfunction

autoload/ale/handlers/gcc.vim

@@ -24,7 +24,7 @@ function! ale#handlers#gcc#HandleGCCFormat(buffer, lines) abort
     " <stdin>:8:5: warning: conversion lacks type at end of format [-Wformat=]
     " <stdin>:10:27: error: invalid operands to binary - (have ‘int’ and ‘char *’)
     " -:189:7: note: $/${} is unnecessary on arithmetic variables. [SC2004]
-    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):(\d+)?:? ([^:]+): ?(.+)$'
+    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):(\d+)?:? ([^:]+): (.+)$'
     let l:output = []
 
     for l:match in ale#util#GetMatches(a:lines, l:pattern)

doc/ale-c.txt

@@ -169,6 +169,14 @@ g:ale_c_flawfinder_options                                 *g:ale-c-flawfinder*
 
   This variable can be used to pass extra options into the flawfinder command.
 
+g:ale_c_flawfinder_error_severity           *g:ale_c_flawfinder_error_severity*
+                                            *b:ale_c_flawfinder_error_severity*
+  Type: |Number|
+  Default: `6`
+
+  This variable can be changed to set the minimum severity to be treated as an
+  error.  This setting also applies to flawfinder for c++.
+
 
 ===============================================================================
 gcc                                                                 *ale-c-gcc*

test/handler/test_flawfinder_handler.vader

@@ -0,0 +1,57 @@
+Before:
+  Save g:ale_c_flawfinder_error_severity
+
+  unlet! g:ale_c_flawfinder_error_severity
+  unlet! b:ale_c_flawfinder_error_severity
+
+  runtime ale_linters/c/flawfinder.vim
+
+After:
+  unlet! g:ale_c_flawfinder_error_severity
+  Restore
+
+Execute(The Flawfinder handler should ignore other lines of output):
+  AssertEqual
+  \ [],
+  \ ale#handlers#flawfinder#HandleFlawfinderFormat(347, [
+  \   'foo',
+  \   'bar',
+  \   'baz',
+  \ ])
+
+Execute(The Flawfinder handler should work):
+  AssertEqual
+  \ [
+    \   {
+  \     'lnum': 31,
+  \     'col': 4,
+  \     'type': 'W',
+  \     'text': "(buffer) strncpy: Easily used incorrectly",
+  \   },
+  \ ],
+  \ ale#handlers#flawfinder#HandleFlawfinderFormat(347, [
+  \ "<stdin>:31:4:  [1] (buffer) strncpy:Easily used incorrectly",
+  \ ])
+
+Execute(The Flawfinder error severity level should be configurable):
+  let b:ale_c_flawfinder_error_severity = 2
+
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 12,
+  \     'col': 4,
+  \     'type': 'E',
+  \     'text': "(buffer) char: Statically-sized arrays can be bad",
+  \   },
+  \   {
+  \     'lnum': 31,
+  \     'col': 4,
+  \     'type': 'W',
+  \     'text': "(buffer) strncpy: Easily used incorrectly",
+  \   },
+  \ ],
+  \ ale#handlers#flawfinder#HandleFlawfinderFormat(bufnr(''), [
+  \ "<stdin>:12:4:  [2] (buffer) char:Statically-sized arrays can be bad",
+  \ "<stdin>:31:4:  [1] (buffer) strncpy:Easily used incorrectly",
+  \ ])