Fix -Wmisleading-indentation false-positive

gcc/c-family/ChangeLog:

	* c-indentation.c (should_warn_for_misleading_indentation):
	Float out and consolidate the calls to get_visual_column that
	are passed guard_exploc as an argument.  Compare
	next_stmt_vis_column with guard_line_first_nws instead of with
	body_line_first_nws.

gcc/testsuite/ChangeLog:

	* c-c++-common/Wmisleading-indentation.c: Augment test.

From-SVN: r228027

gcc/c-family/ChangeLog

+2015-09-22  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	* c-indentation.c (should_warn_for_misleading_indentation):
+	Float out and consolidate the calls to get_visual_column that
+	are passed guard_exploc as an argument.  Compare
+	next_stmt_vis_column with guard_line_first_nws instead of with
+	body_line_first_nws.
+
 2015-09-22  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* c.opt (Wmultiple-inheritance, Wvirtual-inheritance, Wtemplates,

gcc/c-family/c-indentation.c

@@ -341,6 +341,8 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
       unsigned int next_stmt_vis_column;
       unsigned int body_vis_column;
       unsigned int body_line_first_nws;
+      unsigned int guard_vis_column;
+      unsigned int guard_line_first_nws;
       /* If we can't determine it, don't issue a warning.  This is sometimes
 	 the case for input files containing #line directives, and these
 	 are often for autogenerated sources (e.g. from .md files), where
@@ -351,6 +353,11 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
 			      &body_vis_column,
 			      &body_line_first_nws))
 	return false;
+      if (!get_visual_column (guard_exploc,
+			      &guard_vis_column,
+			      &guard_line_first_nws))
+	return false;
+
       if ((body_type != CPP_SEMICOLON
 	   && next_stmt_vis_column == body_vis_column)
 	  /* As a special case handle the case where the body is a semicolon
@@ -365,7 +372,7 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
 	  || (body_type == CPP_SEMICOLON
 	      && body_exploc.line > guard_exploc.line
 	      && body_line_first_nws != body_vis_column
-	      && next_stmt_vis_column == body_line_first_nws))
+	      && next_stmt_vis_column > guard_line_first_nws))
 	{
           /* Don't warn if they are aligned on the same column
 	     as the guard itself (suggesting autogenerated code that doesn't
@@ -395,13 +402,6 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
 	     indentation is misleading).  Using the column of the first
 	     non-whitespace character on the guard line makes that
 	     happen.  */
-	  unsigned int guard_vis_column;
-	  unsigned int guard_line_first_nws;
-	  if (!get_visual_column (guard_exploc,
-				  &guard_vis_column,
-				  &guard_line_first_nws))
-	    return false;
-
 	  if (guard_line_first_nws == body_vis_column)
 	    return false;
 
@@ -462,13 +462,6 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
 	  {
 	    if (body_exploc.line == guard_exploc.line)
 	      {
-		unsigned int guard_vis_column;
-		unsigned int guard_line_first_nws;
-		if (!get_visual_column (guard_exploc,
-					&guard_vis_column,
-					&guard_line_first_nws))
-		  return false;
-
 		if (next_stmt_vis_column > guard_line_first_nws
 		    || (next_tok_type == CPP_OPEN_BRACE
 			&& next_stmt_vis_column == guard_vis_column))

gcc/testsuite/ChangeLog

+2015-09-22  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	* c-c++-common/Wmisleading-indentation.c: Augment test.
+
 2015-09-22  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.dg/diagostic/disable.C: New.

gcc/testsuite/c-c++-common/Wmisleading-indentation.c

@@ -732,6 +732,13 @@ fn_37 (void)
       foo (0);
     }
 
+  if (flagB) /* { dg-message "3: ...this 'if' clause" } */
+    /* blah */;
+   { /* { dg-warning "statement is indented as if" } */
+     foo (0);
+   }
+
+
   if (flagB)
     ;
   else; foo (0); /* { dg-warning "statement is indented as if" } */
@@ -785,6 +792,11 @@ fn_37 (void)
   else if (flagB); /* { dg-message "8: ...this 'if' clause" } */
     foo (2); /* { dg-warning "statement is indented as if" } */
 
+  for (i = 0; /* { dg-message "3: ...this 'for' clause" } */
+       i < 10;
+       i++);
+    foo (i); /* { dg-warning "statement is indented as if" } */
+
 #undef EMPTY
 #undef FOR_EACH
 }
@@ -836,6 +848,12 @@ fn_38 (void)
   if (flagB)
     foo (2);
   foo (3);
+
+  for (i = 0;
+       i < 10;
+       i++
+  );
+  foo (i);
 }
 
 /* The following function contains good indentation which we definitely should
@@ -844,6 +862,8 @@ fn_38 (void)
 void
 fn_39 (void)
 {
+  int i;
+
   if (flagA)
     ;
   if (flagB)
@@ -856,4 +876,9 @@ fn_39 (void)
       foo (1);
   else
     foo (2);
+
+  for (i = 0;
+       i < 10;
+       i++);
+  foo (i);
 }