From 7c0eb3c622eb0882f460805109f244679b340964 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 14 Jul 2022 09:04:23 -0400 Subject: [PATCH] Tighten up parsing logic in gen_node_support.pl. Teach this script to handle function pointer fields honestly. Previously they were just silently ignored, but that's not likely to be a behavior we can accept indefinitely. This mostly entails fixing it so that a field declaration spanning multiple lines can be parsed, because we have a bunch of such fields that're laid out that way. But that's a good improvement in its own right. With that change and a minor regex adjustment, the only struct it fails to parse in the node-defining headers is A_Const, because of the embedded union. The path of least resistance is to move that union declaration outside the struct. Having done those things, we can make it error out if it finds any within-struct syntax it doesn't understand, which seems like a pretty important property for robustness. This commit doesn't change the output files at all; it's just in the way of future-proofing. Discussion: https://postgr.es/m/2593369.1657759779@sss.pgh.pa.us --- src/backend/nodes/gen_node_support.pl | 77 +++++++++++++++++++++++++-- src/include/nodes/parsenodes.h | 28 +++++----- src/include/nodes/pathnodes.h | 5 +- 3 files changed, 90 insertions(+), 20 deletions(-) diff --git a/src/backend/nodes/gen_node_support.pl b/src/backend/nodes/gen_node_support.pl index 96af17516a..975e456ee2 100644 --- a/src/backend/nodes/gen_node_support.pl +++ b/src/backend/nodes/gen_node_support.pl @@ -213,15 +213,39 @@ foreach my $infile (@ARGV) } $file_content .= $raw_file_content; - my $lineno = 0; + my $lineno = 0; + my $prevline = ''; foreach my $line (split /\n/, $file_content) { + # per-physical-line processing $lineno++; chomp $line; $line =~ s/\s*$//; next if $line eq ''; next if $line =~ /^#(define|ifdef|endif)/; + # within a struct, don't process until we have whole logical line + if ($in_struct && $subline > 0) + { + if ($line =~ /;$/) + { + # found the end, re-attach any previous line(s) + $line = $prevline . $line; + $prevline = ''; + } + elsif ($prevline eq '' + && $line =~ /^\s*pg_node_attr\(([\w(), ]*)\)$/) + { + # special case: node-attributes line doesn't end with semi + } + else + { + # set it aside for a moment + $prevline .= $line . ' '; + next; + } + } + # we are analyzing a struct definition if ($in_struct) { @@ -394,7 +418,7 @@ foreach my $infile (@ARGV) } # normal struct field elsif ($line =~ - /^\s*(.+)\s*\b(\w+)(\[\w+\])?\s*(?:pg_node_attr\(([\w(), ]*)\))?;/ + /^\s*(.+)\s*\b(\w+)(\[[\w\s+]+\])?\s*(?:pg_node_attr\(([\w(), ]*)\))?;/ ) { if ($is_node_struct) @@ -441,13 +465,46 @@ foreach my $infile (@ARGV) $my_field_attrs{$name} = \@attrs; } } - else + # function pointer field + elsif ($line =~ + /^\s*([\w\s*]+)\s*\(\*(\w+)\)\s*\((.*)\)\s*(?:pg_node_attr\(([\w(), ]*)\))?;/ + ) { if ($is_node_struct) { - #warn "$infile:$lineno: could not parse \"$line\"\n"; + my $type = $1; + my $name = $2; + my $args = $3; + my $attrs = $4; + + my @attrs; + if ($attrs) + { + @attrs = split /,\s*/, $attrs; + foreach my $attr (@attrs) + { + if ( $attr !~ /^copy_as\(\w+\)$/ + && $attr !~ /^read_as\(\w+\)$/ + && !elem $attr, + qw(equal_ignore read_write_ignore)) + { + die + "$infile:$lineno: unrecognized attribute \"$attr\"\n"; + } + } + } + + push @my_fields, $name; + $my_field_types{$name} = 'function pointer'; + $my_field_attrs{$name} = \@attrs; } } + else + { + # We're not too picky about what's outside structs, + # but we'd better understand everything inside. + die "$infile:$lineno: could not parse \"$line\"\n"; + } } # not in a struct else @@ -709,6 +766,12 @@ _equal${n}(const $n *a, const $n *b) unless $equal_ignore; } } + elsif ($t eq 'function pointer') + { + # we can copy and compare as a scalar + print $cff "\tCOPY_SCALAR_FIELD($f);\n" unless $copy_ignore; + print $eff "\tCOMPARE_SCALAR_FIELD($f);\n" unless $equal_ignore; + } # node type elsif ($t =~ /(\w+)\*/ and elem $1, @node_types) { @@ -980,6 +1043,12 @@ _read${n}(void) unless $no_read; } } + elsif ($t eq 'function pointer') + { + # We don't print these, and we can't read them either + die "cannot read function pointer in struct \"$n\" field \"$f\"\n" + unless $no_read; + } # Special treatments of several Path node fields elsif ($t eq 'RelOptInfo*' && elem 'write_only_relids', @a) { diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index b0c9c5f2ef..98fe1abaa2 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -303,26 +303,26 @@ typedef struct A_Expr /* * A_Const - a literal constant + * + * Value nodes are inline for performance. You can treat 'val' as a node, + * as in IsA(&val, Integer). 'val' is not valid if isnull is true. */ +union ValUnion +{ + Node node; + Integer ival; + Float fval; + Boolean boolval; + String sval; + BitString bsval; +}; + typedef struct A_Const { pg_node_attr(custom_copy_equal, custom_read_write, no_read) NodeTag type; - - /* - * Value nodes are inline for performance. You can treat 'val' as a node, - * as in IsA(&val, Integer). 'val' is not valid if isnull is true. - */ - union ValUnion - { - Node node; - Integer ival; - Float fval; - Boolean boolval; - String sval; - BitString bsval; - } val; + union ValUnion val; bool isnull; /* SQL NULL constant */ int location; /* token location, or -1 if unknown */ } A_Const; diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index 44ffc73f15..69ba254372 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -1098,7 +1098,7 @@ struct IndexOptInfo /* * Remaining fields are copied from the index AM's API struct - * (IndexAmRoutine) + * (IndexAmRoutine). We don't bother to dump them. */ bool amcanorderbyop pg_node_attr(read_write_ignore); bool amoptionalkey pg_node_attr(read_write_ignore); @@ -1111,8 +1111,9 @@ struct IndexOptInfo bool amcanparallel pg_node_attr(read_write_ignore); /* does AM have ammarkpos interface? */ bool amcanmarkpos pg_node_attr(read_write_ignore); + /* AM's cost estimator */ /* Rather than include amapi.h here, we declare amcostestimate like this */ - void (*amcostestimate) (); /* AM's cost estimator */ + void (*amcostestimate) () pg_node_attr(read_write_ignore); }; /*