Add the .namedref() method; currently a lot of duplication with .backref().

README.rst

@@ -72,6 +72,15 @@ regex.backref
 
 	STRING regex.backref(INT ref, STRING fallback="**BACKREF METHOD FAILED**")
 
+.. _func_regex.namedref:
+
+regex.namedref
+--------------
+
+::
+
+	STRING regex.namedref(STRING name, STRING fallback="**NAMEDREF METHOD FAILED**")
+
 .. _func_config_bool:
 
 config_bool

src/tests/namedref.vtc

+# looks like -*- vcl -*-
+
+varnishtest "namedref()"
+
+varnish v1 -vcl {
+	import pcre2 from "${vmod_topbuild}/src/.libs/libvmod_pcre2.so";
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new barbaz = pcre2.regex("(?<bar>bar)(?<baz>baz)");
+		new bazplus = pcre2.regex("(?<baz>baz)(?<dots>.+)");
+	}
+
+	sub vcl_recv {
+		return(synth(200));
+	}
+
+	sub vcl_synth {
+		# Tests task scopes for two different objects.
+		# Numbered backrefs also work with named groups.
+		if (barbaz.match("barbaz") && bazplus.match("bazquux")) {
+			set resp.http.bar-bar
+			    = barbaz.namedref("bar", "err_bar");
+			set resp.http.bar-baz
+			    = barbaz.namedref("baz", "err_baz");
+			set resp.http.baz-baz
+			    = bazplus.namedref("baz", "err_baz");
+			set resp.http.baz-dots
+			    = bazplus.namedref("dots", "err_dots");
+			set resp.http.bar0 = barbaz.backref(0, "error0");
+			set resp.http.bar1 = barbaz.backref(1, "error1");
+			set resp.http.bar2 = barbaz.backref(2, "error2");
+			set resp.http.baz0 = bazplus.backref(0, "error0");
+			set resp.http.baz1 = bazplus.backref(1, "error1");
+			set resp.http.baz2 = bazplus.backref(2, "error2");
+		}
+		else {
+			set resp.status = 999;
+		}
+	}
+} -start
+
+client c1 -repeat 2 {
+	txreq
+	rxresp
+	expect resp.status == "200"
+	expect resp.http.bar-bar == "bar"
+	expect resp.http.bar-baz == "baz"
+	expect resp.http.baz-baz == "baz"
+	expect resp.http.baz-dots == "quux"
+	expect resp.http.bar0 == "barbaz"
+	expect resp.http.bar1 == "bar"
+	expect resp.http.bar2 == "baz"
+	expect resp.http.baz0 == "bazquux"
+	expect resp.http.baz1 == "baz"
+	expect resp.http.baz2 == "quux"
+} -run
+
+# failure
+varnish v1 -vcl {
+	import pcre2 from "${vmod_topbuild}/src/.libs/libvmod_pcre2.so";
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new frobnitz = pcre2.regex("(?<frob>frob)(?<nitz>nitz)");
+		new barbaz = pcre2.regex("(?<bar>bar)(?<baz>baz)");
+		new azbc = pcre2.regex("(?<a>a|(?<z>z))(?<bc>bc)");
+		new foo = pcre2.regex("(?<f>f)(?<o>o)(o)",
+		    no_auto_capture=true);
+	}
+
+	sub vcl_recv {
+		return(synth(200));
+	}
+
+	sub vcl_synth {
+		# Call to namedref() before match()
+		# Also tests the default fallback.
+		set resp.http.nomatch = barbaz.namedref("bar");
+
+		# match() and namedref() now re-use the object's task scope
+		if (barbaz.match("barbaz")) {
+			set resp.http.bar-bar
+			    = barbaz.namedref("bar", "err_bar");
+
+			# no such name
+			set resp.http.bar-quux
+			    = barbaz.namedref("quux", "err_quux");
+
+			# fallback is NULL
+			set resp.http.fallback
+			    = barbaz.namedref("bar", req.http.undef);
+		}
+
+		# match fails
+		set resp.http.frob1 = frobnitz.match("barbaz");
+		# ... so all namedrefs fail
+		set resp.http.frob1-frob
+		    = frobnitz.namedref("frob", "err_frob");
+		set resp.http.frob1-nitz
+		    = frobnitz.namedref("nitz", "err_nitz");
+
+		# match succeeds, then fails again
+		set resp.http.frob-yes = frobnitz.match("frobnitz");
+		set resp.http.frob-no = frobnitz.match("barbaz");
+		# ... so all namedrefs fail, despite previous match
+		set resp.http.frob2-frob
+		    = frobnitz.namedref("frob", "err_frob");
+		set resp.http.frob2-nitz
+		    = frobnitz.namedref("nitz", "err_nitz");
+
+		# namedref "z" is unset
+		set resp.http.azbc = azbc.match("abc");
+		set resp.http.azbc-a = azbc.namedref("a", "err_a");
+		set resp.http.azbc-z = azbc.namedref("z", "err_z");
+		set resp.http.azbc-bc = azbc.namedref("bc", "err_bc");
+
+		# namedrefs succeed with no_auto_capture, as well as
+		# numbered backrefs that correspond to the named
+		# groups, and backref 0, but not the other numbered backrefs.
+		set resp.http.foo = foo.match("foo");
+		set resp.http.foo-f = foo.namedref("f", "err_f");
+		set resp.http.foo-o = foo.namedref("o", "err_o");
+		set resp.http.foo-0 = foo.backref(0, "error0");
+		set resp.http.foo-1 = foo.backref(1, "error1");
+		set resp.http.foo-2 = foo.backref(2, "error2");
+		set resp.http.foo-3 = foo.backref(3, "error3");
+	}
+}
+
+client c1 -repeat 2 {
+	txreq
+	rxresp
+	expect resp.status == "200"
+	expect resp.http.nomatch == "**NAMEDREF METHOD FAILED**"
+	expect resp.http.bar-bar == "bar"
+	expect resp.http.bar-quux == "err_quux"
+	expect resp.http.fallback == "**NAMEDREF METHOD FAILED**"
+	expect resp.http.frob1 == "false"
+	expect resp.http.frob1-frob == "err_frob"
+	expect resp.http.frob1-nitz == "err_nitz"
+	expect resp.http.frob-yes == "true"
+	expect resp.http.frob-no == "false"
+	expect resp.http.frob2-frob == "err_frob"
+	expect resp.http.frob2-nitz == "err_nitz"
+	expect resp.http.azbc == "true"
+	expect resp.http.azbc-a == "a"
+	expect resp.http.azbc-z == "err_z"
+	expect resp.http.azbc-bc == "bc"
+	expect resp.http.foo == "true"
+	expect resp.http.foo-f == "f"
+	expect resp.http.foo-o == "o"
+	expect resp.http.foo-0 == "foo"
+	expect resp.http.foo-1 == "f"
+	expect resp.http.foo-2 == "o"
+	expect resp.http.foo-3 == "error3"
+} -run
+
+logexpect l1 -v v1 -d 1 -g vxid -q "VCL_Error" {
+	expect 0 * Begin req
+	expect * = VCL_Error "^vmod pcre2 error: barbaz.namedref.bar. called without prior match$"
+	expect * = VCL_Error "^vmod pcre2 error: in barbaz.namedref.quux.: unknown substring$"
+ 	expect * = VCL_Error "^vmod pcre2 error: in barbaz.namedref..: fallback is undefined$"
+	expect * = VCL_Error "^vmod pcre2 error: in frobnitz.namedref.frob.: no match$"
+	expect * = VCL_Error "^vmod pcre2 error: in frobnitz.namedref.nitz.: no match$"
+	expect * = VCL_Error "^vmod pcre2 error: in frobnitz.namedref.frob.: no match$"
+	expect * = VCL_Error "^vmod pcre2 error: in frobnitz.namedref.nitz.: no match$"
+ 	expect * = VCL_Error "^vmod pcre2 error: in azbc.namedref.z.: requested value is not set$"
+ 	expect * = VCL_Error "^vmod pcre2 error: in foo.backref.3.: unknown substring$"
+	expect * = End
+} -run

src/vmod_pcre2.c

@@ -572,6 +572,63 @@ vmod_regex_backref(VRT_CTX, struct vmod_pcre2_regex *regex, VCL_INT ref,
 	return fallback;
 }
 
+VCL_STRING
+vmod_regex_namedref(VRT_CTX, struct vmod_pcre2_regex *regex, VCL_STRING name,
+		    VCL_STRING fallback)
+{
+	struct vmod_priv *match_task;
+	pcre2_match_data *mdata;
+	PCRE2_UCHAR *buf;
+	PCRE2_SIZE len;
+	int ret;
+	char *msg;
+	uintptr_t snap;
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(regex, VMOD_PCRE2_REGEX_MAGIC);
+	if (fallback == NULL) {
+		VERR(ctx, "in %s.namedref(): fallback is undefined",
+		     regex->vcl_name);
+		return "**NAMEDREF METHOD FAILED**";
+	}
+	if (name == NULL) {
+		VERR(ctx, "in %s.namedref(<undefined>): name is undefined",
+		     regex->vcl_name);
+		return fallback;
+	}
+
+	match_task = VRT_priv_task(ctx, regex);
+	AN(match_task);
+	if (match_task->priv == NULL) {
+		VERR(ctx, "%s.namedref(%s) called without prior match",
+		     regex->vcl_name, name);
+		return fallback;
+	}
+	WS_Assert_Allocated(ctx->ws, match_task->priv, 0);
+	mdata = match_task->priv;
+
+	if ((ret = pcre2_substring_get_byname(mdata, (PCRE2_SPTR)name, &buf,
+					      &len)) == 0) {
+		WS_Assert_Allocated(ctx->ws, buf, len + 1);
+		return (VCL_STRING)buf;
+	}
+
+	/*
+	 * This error is returned when the ovector was too small, cannot
+	 * happen after using pcre2_match_data_create_from_pattern() to
+	 * get the match data block.
+	 */
+	assert(ret != PCRE2_ERROR_UNAVAILABLE);
+
+	snap = WS_Snapshot(ctx->ws);
+	if ((msg = WS_Printf(ctx->ws, "in %s.namedref(%s)", regex->vcl_name,
+			     name)) == NULL)
+		msg = "";
+	report_pcre2_err(ctx, ret, msg, "");
+	WS_Reset(ctx->ws, snap);
+	return fallback;
+}
+
 /* Functions */
 
 VCL_BOOL

src/vmod_pcre2.vcc

@@ -41,6 +41,9 @@ $Method BOOL .match(PRIV_CALL, PRIV_TASK, STRING subject, INT len=0,
 
 $Method STRING .backref(INT ref, STRING fallback = "**BACKREF METHOD FAILED**")
 
+$Method STRING .namedref(STRING name,
+                         STRING fallback = "**NAMEDREF METHOD FAILED**")
+
 $Function BOOL config_bool(ENUM {JIT, STACKRECURSE, UNICODE})
 
 $Function STRING config_str(ENUM {BSR, JITTARGET, NEWLINE, UNICODE_VERSION,