From 2d11d26113dd88072e09f92ad3f2032a27e4d8ce Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 15 Jul 2006 03:27:42 +0000
Subject: [PATCH] Create a tool to catch #include omissions that might not
result in any compiler warning, specifically #ifdef or #if defined tests on
symbols that are defined in a file not included. The results are a bit noisy
and require care to interpret, but it's a lot better than no tool at all.
---
src/tools/pginclude/README | 6 +
src/tools/pginclude/pgcheckdefines | 240 +++++++++++++++++++++++++++++
2 files changed, 246 insertions(+)
create mode 100755 src/tools/pginclude/pgcheckdefines
diff --git a/src/tools/pginclude/README b/src/tools/pginclude/README
index 0100562cfed..ac6cd7edfe2 100644
--- a/src/tools/pginclude/README
+++ b/src/tools/pginclude/README
@@ -10,6 +10,11 @@ pgcompinclude [-v]
pgrminclude [-v]
remove extra #include's
+pgcheckdefines
+ check for #ifdef tests on symbols defined in files that
+ weren't included --- this is a necessary sanity check on
+ pgrminclude!
+
pgdefine create macro calls for all defines in the file (used by
the above routines)
@@ -22,3 +27,4 @@ order would be:
pgrminclude /src/include
pgcompinclude
pgrminclude /
+ pgcheckdefines
diff --git a/src/tools/pginclude/pgcheckdefines b/src/tools/pginclude/pgcheckdefines
new file mode 100755
index 00000000000..07ae7b5d675
--- /dev/null
+++ b/src/tools/pginclude/pgcheckdefines
@@ -0,0 +1,240 @@
+#! /usr/bin/perl -w
+
+#
+# This script looks for symbols that are referenced in #ifdef or defined()
+# tests without having #include'd the file that defines them. Since this
+# situation won't necessarily lead to any compiler message, it seems worth
+# having an automated check for it. In particular, use this to audit the
+# results of pgrminclude!
+#
+# Usage: configure and build a PG source tree (non-VPATH), then start this
+# script at the top level. It's best to enable as many configure options
+# as you can, especially --enable-cassert which is known to affect include
+# requirements. NB: you MUST use gcc, unless you have another compiler that
+# can be persuaded to spit out the names of referenced include files.
+#
+# The results are necessarily platform-dependent, so use care in interpreting
+# them. We try to process all .c files, even those not intended for the
+# current platform, so there will be some phony failures.
+#
+# $PostgreSQL: pgsql/src/tools/pginclude/pgcheckdefines,v 1.1 2006/07/15 03:27:42 tgl Exp $
+#
+
+use Cwd;
+use File::Basename;
+
+$topdir = cwd();
+
+# Programs to use
+$FIND = "find";
+$MAKE = "make";
+
+#
+# Build arrays of all the .c and .h files in the tree
+#
+# We ignore .h files under src/include/port/, since only the one exposed as
+# src/include/port.h is interesting. (XXX Windows ports have additional
+# files there?) Ditto for .h files in src/backend/port/ subdirectories.
+# Including these .h files would clutter the list of define'd symbols and
+# cause a lot of false-positive results.
+#
+open PIPE, "$FIND * -type f -name '*.c' |"
+ or die "can't fork: $!";
+while (<PIPE>) {
+ chomp;
+ push @cfiles, $_;
+}
+close PIPE or die "$FIND failed: $!";
+
+open PIPE, "$FIND * -type f -name '*.h' |"
+ or die "can't fork: $!";
+while (<PIPE>) {
+ chomp;
+ push @hfiles, $_ unless
+ m|^src/include/port/| ||
+ m|^src/backend/port/\w+/|;
+}
+close PIPE or die "$FIND failed: $!";
+
+#
+# For each .h file, extract all the symbols it #define's, and add them to
+# a hash table. To cover the possibility of multiple .h files defining
+# the same symbol, we make each hash entry a hash of filenames.
+#
+foreach $hfile (@hfiles) {
+ open HFILE, $hfile
+ or die "can't open $hfile: $!";
+ while (<HFILE>) {
+ if (m/^\s*#\s*define\s+(\w+)/) {
+ $defines{$1}{$hfile} = 1;
+ }
+ }
+ close HFILE;
+}
+
+#
+# For each file (both .h and .c), run the compiler to get a list of what
+# files it #include's. Then extract all the symbols it tests for defined-ness,
+# and check each one against the previously built hashtable.
+#
+foreach $file (@hfiles, @cfiles) {
+ ($fname, $fpath) = fileparse($file);
+ chdir $fpath or die "can't chdir to $fpath: $!";
+ #
+ # Ask 'make' to parse the makefile so we can get the correct flags to
+ # use. CPPFLAGS in particular varies for each subdirectory. If we are
+ # processing a .h file, we might be in a subdirectory that has no
+ # Makefile, in which case we have to fake it. Note that there seems
+ # no easy way to prevent make from recursing into subdirectories and
+ # hence printing multiple definitions --- we keep the last one, which
+ # should come from the current Makefile.
+ #
+ if (-f "Makefile" || -f "GNUmakefile") {
+ $MAKECMD = "$MAKE -qp";
+ } else {
+ $subdir = $fpath;
+ chop $subdir;
+ $top_builddir = "..";
+ $tmp = $fpath;
+ while (($tmp = dirname($tmp)) ne '.') {
+ $top_builddir = $top_builddir . "/..";
+ }
+ $MAKECMD = "$MAKE -qp 'subdir=$subdir' 'top_builddir=$top_builddir' -f '$top_builddir/src/Makefile.global'";
+ }
+ open PIPE, "$MAKECMD |"
+ or die "can't fork: $!";
+ while (<PIPE>) {
+ if (m/^CPPFLAGS :?= (.*)/) {
+ $CPPFLAGS = $1;
+ } elsif (m/^CFLAGS :?= (.*)/) {
+ $CFLAGS = $1;
+ } elsif (m/^CFLAGS_SL :?= (.*)/) {
+ $CFLAGS_SL = $1;
+ } elsif (m/^PTHREAD_CFLAGS :?= (.*)/) {
+ $PTHREAD_CFLAGS = $1;
+ } elsif (m/^CC :?= (.*)/) {
+ $CC = $1;
+ }
+ }
+ # If make exits with status 1, it's not an error, it just means make
+ # thinks some files may not be up-to-date. Only complain on status 2.
+ close PIPE;
+ die "$MAKE failed in $fpath\n" if $? != 0 && $? != 256;
+
+ # Expand out stuff that might be referenced in CFLAGS
+ $CFLAGS =~ s/\$\(CFLAGS_SL\)/$CFLAGS_SL/;
+ $CFLAGS =~ s/\$\(PTHREAD_CFLAGS\)/$PTHREAD_CFLAGS/;
+
+ #
+ # Run the compiler (which had better be gcc) to get the inclusions.
+ # "gcc -H" reports inclusions on stderr as "... filename" where the
+ # number of dots varies according to nesting depth.
+ #
+ @includes = ();
+ $COMPILE = "$CC $CPPFLAGS $CFLAGS -H -E $fname";
+ open PIPE, "$COMPILE 2>&1 >/dev/null |"
+ or die "can't fork: $!";
+ while (<PIPE>) {
+ if (m/^\.+ (.*)/) {
+ $include = $1;
+ # Ignore system headers (absolute paths); but complain if a
+ # .c file includes a system header before any PG header.
+ if ($include =~ m|^/|) {
+ warn "$file includes $include before any Postgres inclusion\n"
+ if $#includes == -1 && $file =~ m/\.c$/;
+ next;
+ }
+ # Strip any "./" (assume this appears only at front)
+ $include =~ s|^\./||;
+ # Make path relative to top of tree
+ $ipath = $fpath;
+ while ($include =~ s|^\.\./||) {
+ $ipath = dirname($ipath) . "/";
+ }
+ $ipath =~ s|^\./||;
+ push @includes, $ipath . $include;
+ } else {
+ warn "$CC: $_";
+ }
+ }
+ # The compiler might fail, particularly if we are checking a file that's
+ # not supposed to be compiled at all on the current platform, so don't
+ # quit on nonzero status.
+ close PIPE or warn "$COMPILE failed in $fpath\n";
+
+ #
+ # Scan the file to find #ifdef, #ifndef, and #if defined() constructs
+ # We assume #ifdef isn't continued across lines, and that defined(foo)
+ # isn't split across lines either
+ #
+ open FILE, $fname
+ or die "can't open $file: $!";
+ $inif = 0;
+ while (<FILE>) {
+ $line = $_;
+ if ($line =~ m/^\s*#\s*ifdef\s+(\w+)/) {
+ $symbol = $1;
+ &checkit;
+ }
+ if ($line =~ m/^\s*#\s*ifndef\s+(\w+)/) {
+ $symbol = $1;
+ &checkit;
+ }
+ if ($line =~ m/^\s*#\s*if\s+/) {
+ $inif = 1;
+ }
+ if ($inif) {
+ while ($line =~ s/\bdefined(\s+|\s*\(\s*)(\w+)//) {
+ $symbol = $2;
+ &checkit;
+ }
+ if (!($line =~ m/\\$/)) {
+ $inif = 0;
+ }
+ }
+ }
+ close FILE;
+
+ chdir $topdir or die "can't chdir to $topdir: $!";
+}
+
+exit 0;
+
+# Check an is-defined reference
+sub checkit {
+ # Ignore if symbol isn't defined in any PG include files
+ if (! defined $defines{$symbol}) {
+ return;
+ }
+ #
+ # Try to match source(s) of symbol to the inclusions of the current file
+ # (including itself). We consider it OK if any one matches.
+ #
+ # Note: these tests aren't bulletproof; in theory the inclusion might
+ # occur after the use of the symbol. Given our normal file layout,
+ # however, the risk is minimal.
+ #
+ foreach $deffile (keys %{ $defines{$symbol} }) {
+ return if $deffile eq $file;
+ foreach $reffile (@includes) {
+ return if $deffile eq $reffile;
+ }
+ }
+ #
+ # If current file is a .h file, it's OK for it to assume that one of the
+ # base headers (postgres.h or postgres_fe.h) has been included.
+ #
+ if ($file =~ m/\.h$/) {
+ foreach $deffile (keys %{ $defines{$symbol} }) {
+ return if $deffile eq 'src/include/c.h';
+ return if $deffile eq 'src/include/postgres.h';
+ return if $deffile eq 'src/include/postgres_fe.h';
+ return if $deffile eq 'src/include/pg_config.h';
+ return if $deffile eq 'src/include/pg_config_manual.h';
+ }
+ }
+ #
+ @places = keys %{ $defines{$symbol} };
+ print "$file references $symbol, defined in @places\n";
+ # print "includes: @includes\n";
+}
--
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