checkpatch: check for common memset parameter issues against statments
[linux-2.6.git] / scripts / checkpatch.pl
index e94626c..8199d59 100755 (executable)
@@ -676,6 +676,10 @@ sub ctx_statement_block {
                        if ($off >= $len) {
                                last;
                        }
+                       if ($level == 0 && substr($blk, $off) =~ /^.\s*#\s*define/) {
+                               $level++;
+                               $type = '#';
+                       }
                }
                $p = $c;
                $c = substr($blk, $off, 1);
@@ -738,6 +742,13 @@ sub ctx_statement_block {
                                last;
                        }
                }
+               # Preprocessor commands end at the newline unless escaped.
+               if ($type eq '#' && $c eq "\n" && $p ne "\\") {
+                       $level--;
+                       $type = '';
+                       $off++;
+                       last;
+               }
                $off++;
        }
        # We are truly at the end, so shuffle to the next line.
@@ -1801,6 +1812,8 @@ sub process {
                        $stat =~ s/\n./\n /g;
                        $cond =~ s/\n./\n /g;
 
+#print "stat<$stat>\n";
+
                        # Find the real next line.
                        $realline_next = $line_nr_next;
                        if (defined $realline_next &&
@@ -2781,47 +2794,13 @@ sub process {
                        my $cnt = $realcnt;
                        my ($off, $dstat, $dcond, $rest);
                        my $ctx = '';
-
-                       my $args = defined($1);
-
-                       # Find the end of the macro and limit our statement
-                       # search to that.
-                       while ($cnt > 0 && defined $lines[$ln - 1] &&
-                               $lines[$ln - 1] =~ /^(?:-|..*\\$)/)
-                       {
-                               $ctx .= $rawlines[$ln - 1] . "\n";
-                               $cnt-- if ($lines[$ln - 1] !~ /^-/);
-                               $ln++;
-                       }
-                       $ctx .= $rawlines[$ln - 1];
-
                        ($dstat, $dcond, $ln, $cnt, $off) =
-                               ctx_statement_block($linenr, $ln - $linenr + 1, 0);
+                               ctx_statement_block($linenr, $realcnt, 0);
+                       $ctx = $dstat;
                        #print "dstat<$dstat> dcond<$dcond> cnt<$cnt> off<$off>\n";
                        #print "LINE<$lines[$ln-1]> len<" . length($lines[$ln-1]) . "\n";
 
-                       # Extract the remainder of the define (if any) and
-                       # rip off surrounding spaces, and trailing \'s.
-                       $rest = '';
-                       while ($off != 0 || ($cnt > 0 && $rest =~ /\\\s*$/)) {
-                               #print "ADDING cnt<$cnt> $off <" . substr($lines[$ln - 1], $off) . "> rest<$rest>\n";
-                               if ($off != 0 || $lines[$ln - 1] !~ /^-/) {
-                                       $rest .= substr($lines[$ln - 1], $off) . "\n";
-                                       $cnt--;
-                               }
-                               $ln++;
-                               $off = 0;
-                       }
-                       $rest =~ s/\\\n.//g;
-                       $rest =~ s/^\s*//s;
-                       $rest =~ s/\s*$//s;
-
-                       # Clean up the original statement.
-                       if ($args) {
-                               substr($dstat, 0, length($dcond), '');
-                       } else {
-                               $dstat =~ s/^.\s*\#\s*define\s+$Ident\s*//;
-                       }
+                       $dstat =~ s/^.\s*\#\s*define\s+$Ident(?:\([^\)]*\))?\s*//;
                        $dstat =~ s/$;//g;
                        $dstat =~ s/\\\n.//g;
                        $dstat =~ s/^\s*//s;
@@ -2847,23 +2826,32 @@ sub process {
                                ^\"|\"$
                        }x;
                        #print "REST<$rest> dstat<$dstat> ctx<$ctx>\n";
-                       if ($rest ne '' && $rest ne ',') {
-                               if ($rest !~ /while\s*\(/ &&
-                                   $dstat !~ /$exceptions/)
-                               {
-                                       ERROR("MULTISTATEMENT_MACRO_USE_DO_WHILE",
-                                             "Macros with multiple statements should be enclosed in a do - while loop\n" . "$here\n$ctx\n");
+                       if ($dstat ne '' &&
+                           $dstat !~ /^(?:$Ident|-?$Constant),$/ &&                    # 10, // foo(),
+                           $dstat !~ /^(?:$Ident|-?$Constant);$/ &&                    # foo();
+                           $dstat !~ /^(?:$Ident|-?$Constant)$/ &&                     # 10 // foo()
+                           $dstat !~ /$exceptions/ &&
+                           $dstat !~ /^\.$Ident\s*=/ &&                                # .foo =
+                           $dstat !~ /^do\s*$Constant\s*while\s*$Constant;$/ &&        # do {...} while (...);
+                           $dstat !~ /^for\s*$Constant$/ &&                            # for (...)
+                           $dstat !~ /^for\s*$Constant\s+(?:$Ident|-?$Constant)$/ &&   # for (...) bar()
+                           $dstat !~ /^do\s*{/ &&                                      # do {...
+                           $dstat !~ /^\({/)                                           # ({...
+                       {
+                               $ctx =~ s/\n*$//;
+                               my $herectx = $here . "\n";
+                               my $cnt = statement_rawlines($ctx);
+
+                               for (my $n = 0; $n < $cnt; $n++) {
+                                       $herectx .= raw_line($linenr, $n) . "\n";
                                }
 
-                       } elsif ($ctx !~ /;/) {
-                               if ($dstat ne '' &&
-                                   $dstat !~ /^(?:$Ident|-?$Constant)$/ &&
-                                   $dstat !~ /$exceptions/ &&
-                                   $dstat !~ /^\.$Ident\s*=/ &&
-                                   $dstat =~ /$Operators/)
-                               {
+                               if ($dstat =~ /;/) {
+                                       ERROR("MULTISTATEMENT_MACRO_USE_DO_WHILE",
+                                             "Macros with multiple statements should be enclosed in a do - while loop\n" . "$herectx");
+                               } else {
                                        ERROR("COMPLEX_MACRO",
-                                             "Macros with complex values should be enclosed in parenthesis\n" . "$here\n$ctx\n");
+                                             "Macros with complex values should be enclosed in parenthesis\n" . "$herectx");
                                }
                        }
                }
@@ -3132,6 +3120,28 @@ sub process {
                             "Avoid line continuations in quoted strings\n" . $herecurr);
                }
 
+# Check for misused memsets
+               if (defined $stat && $stat =~ /\bmemset\s*\((.*)\)/s) {
+                       my $args = $1;
+
+                       # Flatten any parentheses and braces
+                       while ($args =~ s/\([^\(\)]*\)/10/s ||
+                              $args =~ s/\{[^\{\}]*\}/10/s ||
+                              $args =~ s/\[[^\[\]]*\]/10/s)
+                       {
+                       }
+                       # Extract the simplified arguments.
+                       my ($ms_addr, $ms_val, $ms_size) =
+                                               split(/\s*,\s*/, $args);
+                       if ($ms_size =~ /^(0x|)0$/i) {
+                               ERROR("MEMSET",
+                                     "memset size is 3rd argument, not the second.\n" . $herecurr);
+                       } elsif ($ms_size =~ /^(0x|)1$/i) {
+                               WARN("MEMSET",
+                                    "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . $herecurr);
+                       }
+               }
+
 # check for new externs in .c files.
                if ($realfile =~ /\.c$/ && defined $stat &&
                    $stat =~ /^.\s*(?:extern\s+)?$Type\s+($Ident)(\s*)\(/s)
@@ -3303,12 +3313,6 @@ sub process {
                        WARN("EXPORTED_WORLD_WRITABLE",
                             "Exporting world writable files is usually an error. Consider more restrictive permissions.\n" . $herecurr);
                }
-
-               # Check for memset with swapped arguments
-               if ($line =~ /memset.*\,(\ |)(0x|)0(\ |0|)\);/) {
-                       ERROR("MEMSET",
-                             "memset size is 3rd argument, not the second.\n" . $herecurr);
-               }
        }
 
        # If we have no input at all, then there is nothing to report on