Replaced regex for matching multi-line function calls

Instead use a more complex system that finds the matching closing
bracket and checks all the lines in between to check one parameter only
on each line.

It handles nested function calls by skipping over their whole parameter
list (since we don't require nested functions be separated onto
individual lines just because the outer call is. Instead these get
checked when we get to this function call separately.

Author: thk123

CODING_STANDARD

@@ -11,6 +11,8 @@ Whitespaces:
     - For brackets, break after the bracket
       - In the case of function calls, put each argument on a separate line if
         they do not fit after one line break
+      - Nested function calls do not need to be broken up into separate lines even
+        if the outer function call does.
 - If a method is bigger than 50 lines, break it into parts.
 - Put matching { } into the same column.
 - No spaces around operators (=, +, ==, ...)

regression/cpp-linter/multi-line-function-call1/main.cpp

@@ -0,0 +1,79 @@
+/*******************************************************************\
+
+Module: Lint Examples
+
+Author: Thomas Kiley, thomas@diffblue.com
+
+\*******************************************************************/
+
+/*******************************************************************\
+
+Function: fun
+
+ Inputs:
+
+ Outputs:
+
+ Purpose:
+
+\*******************************************************************/
+
+static void fun()
+{
+  // Correct
+  foo(
+    x,
+    y);
+
+  // Incorrect, x should be on the next line
+  foo(x,
+    y);
+
+  // Incorrect indent should be only 2
+  foo(
+      x,
+      y);
+
+  // Correct
+  int x=bar(
+    x,
+    y);
+
+  // Incorrect, x should be on the next line
+  int x=bar(x,
+    y);
+
+  // Incorrect indent should be only 2
+  int x=bar(
+      x,
+      y);
+
+  // Correct
+  *model=baz(
+    x,
+    y);
+
+  // Incorrect, x should be on the next line
+  *model=baz(x,
+    y);
+
+  // Incorrect indent should be only 2
+  *model=baz(
+      x,
+      y);
+
+  // Correct
+  var->fun(
+    x,
+    y);
+
+  // Incorrect, x should be on the next line
+  var->fun(x,
+    y);
+
+  // Incorrect indent should be only 2
+  var->fun(
+      x,
+      y);
+}
+

regression/cpp-linter/multi-line-function-call1/test.desc

@@ -0,0 +1,15 @@
+CORE
+main.cpp
+
+^main\.cpp:29:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:34:  Indent of wrapped parenthesized expression or parameter or argument list should be 2  \[whitespace/indent\] \[4\]
+^main\.cpp:43:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:48:  Indent of wrapped parenthesized expression or parameter or argument list should be 2  \[whitespace/indent\] \[4\]
+^main\.cpp:57:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:62:  Indent of wrapped parenthesized expression or parameter or argument list should be 2  \[whitespace/indent\] \[4\]
+^main\.cpp:71:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:76:  Indent of wrapped parenthesized expression or parameter or argument list should be 2  \[whitespace/indent\] \[4\]
+^Total errors found: 8$
+^EXIT=1$
+^SIGNAL=0$
+--

regression/cpp-linter/multi-line-function-call2/main.cpp

@@ -0,0 +1,67 @@
+/*******************************************************************\
+
+Module: Lint Examples
+
+Author: Thomas Kiley, thomas@diffblue.com
+
+\*******************************************************************/
+
+/*******************************************************************\
+
+Function: fun
+
+ Inputs:
+
+ Outputs:
+
+ Purpose:
+
+\*******************************************************************/
+
+static void fun()
+{
+  // Incorrect, call should be on a new line
+  nested(call(),
+    another_param);
+
+  // Incorrect - should be indented by 2
+  nested(
+         call(),
+         another_param);
+
+  // Correct
+  nested(
+    call(),
+    another_param);
+
+  // Correct
+  twice(
+    nested(
+      call(
+        param1),
+      param2),
+    param3)
+
+  // Correct
+  foo(
+    bar(x, y),
+    z);
+
+  // Correct
+  foo(
+    bar(
+      x,
+      y),
+    z);
+
+  // Incorrect, the bar arguments have been split up therefore
+  // they all should be split up
+  foo(
+    bar(x,
+      y),
+    z);
+
+  // Incorrect bar should be on the next line
+  foo(bar(x, y),
+    z);
+}

regression/cpp-linter/multi-line-function-call2/test.desc

@@ -0,0 +1,11 @@
+CORE
+main.cpp
+
+^main\.cpp:24:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:29:  Indent of wrapped parenthesized expression or parameter or argument list should be 2  \[whitespace/indent\] \[4\]
+^main\.cpp:60:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^main\.cpp:65:  If parameters or arguments require a line break, each parameter should be put on its own line\.  \[whitespace/indent\] \[4\]
+^Total errors found: 4$
+^EXIT=1$
+^SIGNAL=0$
+--

regression/cpp-linter/multi-line-function-call3/main.cpp

@@ -0,0 +1,47 @@
+/*******************************************************************\
+
+Module: Lint Examples
+
+Author: Thomas Kiley, thomas@diffblue.com
+
+\*******************************************************************/
+
+/*******************************************************************\
+
+Function: fun
+
+ Inputs:
+
+ Outputs:
+
+ Purpose:
+
+\*******************************************************************/
+
+static void fun()
+{
+  // Correct as for loop not function
+  for(int x=0;
+    x<10;
+    ++x)
+  {}
+
+  // Correct as an if statement not a function
+  if(a==b ||
+    c==d)
+  {
+    do_something();
+  }
+
+  // Correct as ranged based for loop not function
+  for(x:
+    list)
+  {}
+
+  // Correct since if statement
+  if(some_check(with, params)==
+    some_value)
+  {
+    do_something();
+  }
+}

regression/cpp-linter/multi-line-function-call3/test.desc

@@ -0,0 +1,7 @@
+CORE
+main.cpp
+
+^Total errors found: 0$
+^EXIT=0$
+^SIGNAL=0$
+--

scripts/cpplint.py

@@ -4686,9 +4686,75 @@ def CheckStyle(filename, clean_lines, linenum, file_extension, nesting_state,
   if linenum>0:
     while prev_initial_spaces < len(prev) and prev[prev_initial_spaces] == ' ':
       prev_initial_spaces += 1
-  if Search(r'\([^\)]*,$', elided_line) or Search(r'\(\[^\)]*, $', elided_line):
-    error(filename, linenum, 'whitespace/indent', 4,
-          'If parameters or arguments require a line break, each parameter should be put on its own line.')
+  # here a regex isn't sufficent we need a stack to match brackets
+  # because even an open bracket and a , at the end might just be function call
+  # as a parameter.
+  # Instead the rule we try to apply here is:
+  #  - if we find an opening bracket, we find the matching closing bracket
+  #  - if the bracket is on a different line we require all of the parameters to be on a separate line
+  #  - if there is another opening bracket Skip to the closing bracket as will be checked in a subsequent line check
+  #  - ignore the line if it is a for/if etc since rules are different
+
+  # Look for an opening bracket that doesn't have a semi-colon on the same line
+  bracket_search = Search(r'(?P<bracket>\()[^;]*,[^;]*$', elided_line)
+
+  # Exclude the check if any of these keywords are present
+  # They could trip us up as they have different formatting rules to functions
+  keyword_search = Search(r'\b(if|for|while|catch|switch)\b', elided_line)
+
+  if bracket_search and not keyword_search:
+    open_bracket_pos = bracket_search.start('bracket')
+    close_line, close_linenum, close_pos = CloseExpression(clean_lines, linenum, open_bracket_pos)
+    if close_pos != -1:
+      # If the closing line is different from the opening line we need to
+      # verify that each of the parameters are on separate lines
+      if close_linenum != linenum:
+        # The first line needs to have no parameters on it
+        if(Search(r'\(.+', elided_line)):
+          error(filename, linenum, 'whitespace/indent', 4,
+                'If parameters or arguments require a line break, each parameter should be put on its own line.')
+
+        # For each line afer we need to verify it consists of exactly one parameter
+        # Except if we find an opening bracket - in this case we ignore everything until the closing
+        # bracket (any errors within these brackets will be picked up when we check this line)
+        start_linenum = linenum + 1
+        while(start_linenum < close_linenum):
+          arg_line = clean_lines.elided[start_linenum]
+          nested_bracket_search = Search('\(', arg_line)
+          if nested_bracket_search:
+            nested_open_bracket_pos = nested_bracket_search.start()
+            # Just because we are calling a nested function doesn't mean
+            # we allow multiple parameters on the line
+            if(Search(',', arg_line[:nested_open_bracket_pos])):
+              error(filename, start_linenum, 'whitespace/indent', 4,
+                    'If parameters or arguments require a line break, each parameter should be put on its own line.')
+
+            nested_close_line, nested_close_linenum, _ = CloseExpression(clean_lines, start_linenum, nested_open_bracket_pos)
+
+            # If anything other closing statements or commas appear there is another parameter after the nested call
+            if not Search(r'\)(,|\)|;)*', nested_close_line):
+              error(filename, start_linenum, 'whitespace/indent', 4,
+                    'If parameters or arguments require a line break, each parameter should be put on its own line.')
+            # Skip to the end of the bracket
+            start_linenum = nested_close_linenum
+
+          start_linenum+=1
+        # For the final line we also need to check one parameter on it
+        # e.g. we require bracket on same line as last parameter
+        # foo(
+        #   x);
+        if not Search(r'^\s*[^,]+\)', close_line):
+          # If this is true, the we failed because we just had the close bracket
+          if Search(r'[^,]*\)', close_line):
+            error(filename, close_linenum, 'whitespace/indent', 4,
+                  'If parameters or arguments require a line break, the closing bracket should be on the same line as the final parameter')
+          else:
+            # In this case the problem is we had a bracket
+            # i.e. more than one parameter on the last line
+            error(filename, close_linenum, 'whitespace/indent', 4,
+                  'If parameters or arguments require a line break, each parameter should be put on its own line.')
+
+
   if (Search(r'\([^\)]*$', elided_prev) and initial_spaces-2 != prev_initial_spaces) and not Search(r'for|while|if|;', elided_prev):
     error(filename, linenum, 'whitespace/indent', 4,
           'Indent of wrapped parenthesized expression or parameter or argument list should be 2')