foo

Author: jemarch

HACKING

@@ -200,5 +200,10 @@ contains a list of suppresions.
 Invoke valgrind with --suppressions=etc/boehm-gc.suppressions
 
 If despite using the suppressions file you see some spurious warning,
-please use --gen-suppressions=yes and add the new suppessions to
-boehm-gc.suppressions.
+please use:
+
+$ valgrind --tool=memcheck --gen-suppressions=all --log-file=raw.log
+
+Then process raw.log with the etc/parse-valgrind-suppressions.sh
+script, wilcard the result as much as you can, and append the results
+to etc/boehm-gc.suppressions.

etc/parse-valgrind-suppressions.sh

@@ -0,0 +1,78 @@
+#! /usr/bin/awk -f
+
+# A script to extract the actual suppression info from the output of
+# (for example) valgrind --leak-check=full --show-reachable=yes
+# --error-limit=no --gen-suppressions=all ./minimal The desired bits
+# are between ^{ and ^} (including the braces themselves).  The
+# combined output should either be appended to
+# /usr/lib/valgrind/default.supp, or placed in a .supp of its own If
+# the latter, either tell valgrind about it each time with
+# --suppressions=<filename>, or add that line to ~/.valgrindrc
+
+# NB This script uses the |& operator, which I believe is
+# gawk-specific. In case of failure, check that you're using gawk
+# rather than some other awk
+
+# The script looks for suppressions. When it finds one it stores it
+# temporarily in an array, and also feeds it line by line to the
+# external app 'md5sum' which generates a unique checksum for it.  The
+# checksum is used as an index in a different array. If an item with
+# that index already exists the suppression must be a duplicate and is
+# discarded.
+
+BEGIN { suppression=0; md5sum = "md5sum" }
+# If the line begins with '{', it's the start of a supression; so
+# set the var and initialise things
+/^{/  {
+       suppression=1;  i=0; next 
+   }
+   # If the line begins with '}' its the end of a suppression
+   /^}/  {
+    if (suppression)
+       { suppression=0;
+         close(md5sum, "to")  # We've finished sending data to
+         # md5sum, so close that part of the
+         # pipe
+         ProcessInput()       # Do the slightly-complicated stuff in functions
+         delete supparray     # We don't want subsequent suppressions to append to it!
+       }
+}
+# Otherwise, it's a normal line. If we're inside a supression, store
+# it, and pipe it to md5sum. Otherwise it's cruft, so ignore it
+{ if (suppression)
+     { 
+         supparray[++i] = $0
+         print |& md5sum
+     }
+}
+
+function ProcessInput()
+{
+    # Pipe the result from md5sum, then close it     
+    md5sum |& getline result
+    close(md5sum)
+    # gawk can't cope with enormous ints like $result would be, so
+    # stringify it first by prefixing a definite string
+    resultstring = "prefix"result
+    
+    if (! (resultstring in chksum_array) )
+        {
+            chksum_array[resultstring] = 0;  # This checksum hasn't been
+                                             # seen before, so add it to
+                                             # the array
+            OutputSuppression()              # and output the contents
+                                             # of the suppression
+        }
+}
+       
+function OutputSuppression()
+{
+    # A suppression is surrounded by '{' and '}'. Its data was stored
+    # line by line in the array
+    print "{"  
+    for (n=1; n <= i; ++n)
+        {
+            { print supparray[n] }
+            print "}" 
+        }
+}