add libspectre (#660)

* add libspectre

* disable libgs check

packages/l/libspectre/xmake.lua

@@ -0,0 +1,40 @@
+package("libspectre")
+
+    set_homepage("https://www.freedesktop.org/wiki/Software/libspectre/")
+    set_description("libspectre is a small library for rendering Postscript documents.")
+    set_license("GPL-2.0")
+
+    add_urls("http://libspectre.freedesktop.org/releases/libspectre-$(version).tar.gz")
+    add_versions("0.2.9", "49ae9c52b5af81b405455c19fe24089d701761da2c45d22164a99576ceedfbed")
+
+    add_deps("ghostscript")
+    on_install("macosx", "linux", function (package)
+        local configs = {"--disable-dependency-tracking", "--disable-silent-rules"}
+        table.insert(configs, "--enable-shared=" .. (package:config("shared") and "yes" or "no"))
+        table.insert(configs, "--enable-static=" .. (package:config("shared") and "no" or "yes"))
+        if package:config("pic") ~= false then
+            table.insert(configs, "--with-pic")
+        end
+        if package:is_plat("macosx") then
+            -- patch configure to make ci happy
+            io.replace("configure", "have_libgs=no", "have_libgs=yes", {plain = true})
+        end
+        local cppflags = {}
+        local ldflags = {}
+        for _, dep in ipairs(package:orderdeps()) do
+            local fetchinfo = dep:fetch()
+            if fetchinfo then
+                for _, includedir in ipairs(fetchinfo.includedirs or fetchinfo.sysincludedirs) do
+                    table.insert(cppflags, "-I" .. includedir)
+                end
+                for _, linkdir in ipairs(fetchinfo.linkdirs) do
+                    table.insert(ldflags, "-L" .. linkdir)
+                end
+            end
+        end
+        import("package.tools.autoconf").install(package, configs, {cppflags = cppflags, ldflags = ldflags})
+    end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("spectre_document_get_format", {includes = "libspectre/spectre.h"}))
+    end)