#!/bin/sh
#
# flintNullPointers-- look for misuses of null pointers, and
#	for variables assumed to be initialized to zero.
#	Common on Sequent and Vaxen.
#
#	Runs flint, looks for the following messages:
#	32    Field size (member 'Symbol') should not be zero  -- The
#	54    Division by 0  -- The constant 0 was used on the right
#	84    sizeof object is zero or object is undefined  -- A sizeof
#	85    Array 'Symbol' has dimension 0  -- An array (named Symbol)
#	413   Likely use of null pointer 'Symbol' in [left/right]
#	414   Possible division by 0  -- The second argument to either
#	415   access of out-of-bounds pointer ('Integer' beyond end of
#	416   creation of out-of-bounds pointer ('Integer' beyond end of
#	418   Passing null pointer to function 'Symbol', Context
#	419   Apparent data overrun for function 'Symbol', argument
#	420   Apparent access beyond array for function 'Symbol',
#	423   Creation of memory leak in assignment to variable 'Symbol'
#	530   Symbol 'Symbol' (Location) not initialized  -- An auto
#	553   Undefined preprocessor variable 'Name', assumed 0  -- The
#	564   variable 'Symbol' depends on order of evaluation  -- The
#	603   Symbol 'Symbol' (Location) not initialized  -- The address
#	613   Possible use of null pointer 'Symbol' in [left/right]
#	644   Variable 'Symbol' (Location) may not have been initialized
#	645   Symbol 'Symbol' (Location) may not have been initialized
#	661   possible access of out-of-bounds pointer ('Integer' beyond
#	662   possible creation of out-of-bounds pointer ('Integer'
#	668   Possibly passing a null pointer to function 'Symbol',
#	669   Possible data overrun for function 'Symbol', argument
#	670   Possible access beyond array for function 'Symbol',
#	671   Possibly passing to function 'Symbol' a negative value
#	672   Possible memory leak in assignment to pointer 'Symbol'  --
#	673   Possibly inappropriate deallocation (Name1) for 'Name2'
#	727   Symbol 'Symbol' (Location) not explicitly initialized  --
#	728   Symbol 'Symbol' (Location) not explicitly initialized  --
#	729   Symbol 'Symbol' (Location) not explicitly initialized  --
#	738   Symbol 'Symbol' (Location) not explicitly initialized  --
#	771   Symbol 'Symbol' (Location) conceivably not initialized  --
#	772   Symbol 'Symbol' (Location) conceivably not initialized  --
#	778   Constant expression evaluates to 0 in operation: String
#	780   Vacuous array element  -- A declaration of an array looks
#	784   Nul character truncated from string  -- During
#	794   Conceivable use of null pointer 'Symbol' in [left/right]
#	795   Conceivable division by 0  -- In a division or modulus
#	796   Conceivable access of out-of-bounds pointer ('Integer'
#	797   Conceivable creation of out-of-bounds pointer ('Integer'
#	802   Conceivably passing a null pointer to function 'Symbol',
#	803   Conceivable data overrun for function 'Symbol', argument
#	804   Conceivable access beyond array for function 'Symbol',
#	941   Result 0 due to operand(s) equaling 0 in operation
#	1008  Expected '0' to follow '=', text ignored  -- Some
#	1401  member symbol 'Symbol' (Location) not initialized by
#	1402  member 'Symbol' (Location) not initialized  -- The
#	1403  member 'Symbol' (Location) not initialized  -- The
#	1501  data member 'Symbol' has zero size  -- A data member had
#	1532  Symbol 'Symbol' not checking argument for NULL  -- This
#	1541  member 'Symbol' (Location) possibly not initialized by
#	1542  member 'Symbol' (Location) possibly not initialized  --
#	1543  member 'Symbol' (Location) possibly not initialized  --
#	1741  member 'Symbol' (Location) conceivably not initialized by
#	1742  member 'Symbol' (Location) conceivably not initialized  --
#	1743  member 'Symbol' (Location) conceivably not initialized  --
#	1744  member 'Symbol' (Location) possibly not initialized by
#
set -x	
ProgName=`basename $0`
Verbose=1

# Turn on filename/linenumbers, use one-line errors for greping.
FLINTOPTS='-hF1 -b'

main() {
	if [ $# -lt 1 ]; then
		say "$ProgName error: you must supply at least one c or c++ file"
		say "Usage: $0 [-v] file"
		exit 1
	fi
	if [ "$1" = "-v" ]; then
		Verbose=1
		shift
	fi
	name=$1


	flint $FLINTOPTS "$@" 2>&1 |\
	if [ $Verbose -eq 1 ]; then
		cat
	else
		postprocess 
	fi

}

#
# postprocess -- filter for interesting lines.
#
# Inputs are of the form:
# imaVax.c  22  Error 322: Unable to open 
#      include file 'stdio.h'
#
postprocess() {

	egrep -v -e '^---' |\
	nawk '
	BEGIN { prev = ""; }
	/^[ \t]+/ {
		# A second line.
		print prev " " $0;
		prev = "";
		next;
	}
	/.*/ {
		# A first line.
		if (prev == "") {
			prev = $0
		}
		else {
			print prev
		}
	}
	END { print prev; }
' | nawk '
	$4 ~ /^32:|^54:|^84:|^85:|^413:|^414:|^415:|^416:|^418:|^419:|^420:/ \
	|| $4 ~ /^423:|^530:|^553:|^564:|^603:|^613:|^644:|^645:|^661:|^662:/ \
	|| $4 ~ /^668:|^669:|^670:|^671:|^672:|^673:|^727:|^728:|^729:/ \
	|| $4 ~ /^738:|^771:|^772:|^778:|^780:|^784:|^794:|^795:|^796:/ \
	|| $4 ~ /^797:|^802:|^803:|^804:|^941:|^1008:|^1401:|^1402:|^1403:/ \
	|| $4 ~ /^1501:|^1532:|^1541:|^1542:|^1543:|^1741:|^1742:|^1743:/ \
	|| $4 ~ /^1744:/ {
		print $0;
	}
'
}

say() {
	echo "$@" 1>&2
}

main "$@"