3 files changed, 103 insertions, 15 deletions
diff --git a/doc/src/sgml/Makefile b/doc/src/sgml/Makefile
index b53b2694a6b..4d45b805da2 100644
--- a/doc/src/sgml/Makefile
+++ b/doc/src/sgml/Makefile
@@ -124,7 +124,7 @@ ifeq ($(STYLE),website)
 XSLTPROC_HTML_FLAGS += --param website.stylesheet 1
 endif
 
-html: html-stamp
+html: check html-stamp
 
 html-stamp: stylesheet.xsl postgres-full.xml $(ALL_IMAGES)
 	$(XSLTPROC) $(XMLINCLUDE) $(XSLTPROCFLAGS) $(XSLTPROC_HTML_FLAGS) $(wordlist 1,2,$^)
@@ -200,8 +200,8 @@ MAKEINFO = makeinfo
 ##
 
 # Quick syntax check without style processing
-check: postgres.sgml $(ALL_SGML) check-tabs check-nbsp
-	$(XMLLINT) $(XMLINCLUDE) --noout --valid $<
+check: postgres.sgml $(ALL_SGML)
+	$(PERL) $(srcdir)/sgml_syntax_check.pl --xmllint "$(XMLLINT)" --srcdir $(srcdir)
 
 
 ##
@@ -261,18 +261,6 @@ clean-man:
 
 endif # sqlmansectnum != 7
 
-# tabs are harmless, but it is best to avoid them in SGML files
-check-tabs:
-	@( ! grep '	' $(wildcard $(srcdir)/*.sgml $(srcdir)/func/*.sgml $(srcdir)/ref/*.sgml $(srcdir)/*.xsl) ) || \
-	(echo "Tabs appear in SGML/XML files" 1>&2;  exit 1)
-
-# Non-breaking spaces are harmless, but it is best to avoid them in SGML files.
-# Use perl command because non-GNU grep or sed could not have hex escape sequence.
-check-nbsp:
-	@ ( $(PERL) -ne '/\xC2\xA0/ and print("$$ARGV:$$_"),$$n++; END {exit($$n>0)}' \
-	  $(wildcard $(srcdir)/*.sgml $(srcdir)/func/*.sgml $(srcdir)/ref/*.sgml $(srcdir)/*.xsl $(srcdir)/images/*.xsl) ) || \
-	(echo "Non-breaking spaces appear in SGML/XML files" 1>&2;  exit 1)
-
 ##
 ## Clean
 ##
diff --git a/doc/src/sgml/meson.build b/doc/src/sgml/meson.build
index 6ae192eac68..ce0dea587cd 100644
--- a/doc/src/sgml/meson.build
+++ b/doc/src/sgml/meson.build
@@ -306,3 +306,26 @@ endif
 if alldocs.length() != 0
   alias_target('alldocs', alldocs)
 endif
+
+sgml_syntax_check = files(
+  'sgml_syntax_check.pl'
+)
+
+test(
+  'sgml_syntax_check',
+  perl,
+  protocol: 'exitcode',
+  suite: 'doc',
+  args: [
+    sgml_syntax_check,
+    '--xmllint',
+      '@0@ --nonet'.format(xmllint_bin.full_path()),
+    '--srcdir',
+      meson.current_source_dir(),
+    '--builddir',
+      meson.current_build_dir(),
+  ],
+  depends: doc_generated
+)
+
+testprep_targets += doc_generated
diff --git a/doc/src/sgml/sgml_syntax_check.pl b/doc/src/sgml/sgml_syntax_check.pl
new file mode 100755
index 00000000000..2264700a453
--- /dev/null
+++ b/doc/src/sgml/sgml_syntax_check.pl
@@ -0,0 +1,77 @@
+# /usr/bin/perl
+
+# Copyright (c) 2025, PostgreSQL Global Development Group
+
+# doc/src/sgml/sgml_syntax_check.pl
+
+use strict;
+use warnings FATAL => 'all';
+use Getopt::Long;
+
+use File::Find;
+
+my $xmllint;
+my $srcdir;
+my $builddir;
+
+GetOptions(
+	'xmllint:s' => \$xmllint,
+	'srcdir:s' => \$srcdir,
+	'builddir:s' => \$builddir) or die "$0: wrong arguments";
+
+die "$0: --srcdir must be specified\n" unless defined $srcdir;
+
+my $xmlinclude = "--path . --path $srcdir";
+$xmlinclude .= " --path $builddir" if defined $builddir;
+
+# find files to process - all the sgml and xsl files (including in subdirectories)
+my @files_to_process;
+my @dirs_to_search = ($srcdir);
+push @dirs_to_search, $builddir if defined $builddir;
+find(
+	sub {
+		return unless -f $_;
+		return if $_ !~ /\.(sgml|xsl)$/;
+		push @files_to_process, $File::Find::name;
+	},
+	@dirs_to_search,);
+
+# tabs and non-breaking spaces are harmless, but it is best to avoid them in SGML files
+sub check_tabs_and_nbsp
+{
+	my $errors = 0;
+	for my $f (@files_to_process)
+	{
+		open my $fh, "<:encoding(UTF-8)", $f or die "Can't open $f: $!";
+		my $line_no = 0;
+		while (<$fh>)
+		{
+			$line_no++;
+			if (/\t/)
+			{
+				print STDERR "Tab found in $f:$line_no\n";
+				$errors++;
+			}
+			if (/\xC2\xA0/)
+			{
+				print STDERR "$f:$line_no: contains non-breaking space\n";
+				$errors++;
+			}
+		}
+		close($fh);
+	}
+
+	if ($errors)
+	{
+		die "Tabs and/or non-breaking spaces appear in SGML/XML files\n";
+	}
+}
+
+sub run_xmllint
+{
+	my $cmd = "$xmllint $xmlinclude --noout --valid postgres.sgml";
+	system($cmd) == 0 or die "xmllint validation failed\n";
+}
+
+run_xmllint();
+check_tabs_and_nbsp();