Allow the use of a valac with a different name

This is useful e.g. for testing git master installed with
--disable-unversioned.

The two changes made are to have VALAC set only if not already set in
Makefile, and to use the environment setting of VALAC in
valadoc-example-tester.

Author: rrthomas

Makefile

@@ -1,7 +1,7 @@
-VALAC = valac
+VALAC ?= valac
 PACKAGES ?= --all
 GENERATOR_OPTS ?= --disable-devhelp --skip-existing
-VALAC_VERSION := $(shell vala --api-version | awk -F. '{ print "0."$$2 }')
+VALAC_VERSION := $(shell $(VALAC) --api-version | awk -F. '{ print "0."$$2 }')
 VAPIDIR := $(shell pkg-config --variable vapidir libvala-$(VALAC_VERSION))
 VALAFLAGS = -g -X -w
 PREFIX = "stable"

src/generator.vala

@@ -58,7 +58,7 @@ public class Valadoc.IndexGenerator : Valadoc.ValadocOrgDoclet {
 
 		// Unversioned vapi directory:
 		try {
-			Process.spawn_command_line_sync ("pkg-config --variable=vapidir vapigen", out standard_output, out standard_error, out exit_status);
+			Process.spawn_command_line_sync ("pkg-config --variable=vapidir vapigen-%s".printf (Vala.API_VERSION), out standard_output, out standard_error, out exit_status);
 			if (exit_status == 0) {
 				paths += standard_output.strip ();
 			}

src/valadoc-example-tester.vala

@@ -60,7 +60,8 @@ public class ExampleTester : ExampleParser {
 	protected override void compile (string str) throws MarkupError {
 		string cmnd = str.strip ();
 
-		bool is_valac_call = str.has_prefix ("valac ");
+		const string VALAC_PREFIX = "valac ";
+		bool is_valac_call = str.has_prefix (VALAC_PREFIX);
 		bool is_schema_call = str.has_prefix ("glib-compile-schemas");
 
 		// We only check for sanity, not for safety
@@ -70,6 +71,8 @@ public class ExampleTester : ExampleParser {
 		}
 
 		if (is_valac_call) {
+			cmnd = Environment.get_variable ("VALAC") + " " +
+				cmnd.substring (VALAC_PREFIX.length);
 			cmnd += " --fatal-warnings";
 			if (example_deprecated == true) {
 				cmnd += " --enable-deprecated";