Parse platform support as a dependency.

Platform strings used in override tables or the supported_platform list is a dependency string. The deps.match_platform function will compare this string to the detected platform and system name. The old cfg.is_platform function matches only plain strings against built-in platform names (like it always has).
luarocks · whoopdedo · Aug 28, 2013 · Aug 28, 2013 · Aug 30, 2013 · Aug 31, 2013
commit 96159d02ee332e2412603b1fdce56927e2a09e91
diff --git a/src/luarocks/cfg.lua b/src/luarocks/cfg.lua
@@ -512,18 +512,17 @@ end
 user_agent = "LuaRocks/"..program_version.." "..arch
 
 --- Check if platform was detected
+-- Compare a string against the standard system names.
+-- If you want to match the full system name or version then use
+-- deps.match_platform
 -- @param query string: The platform name to check.
 -- @return boolean: true if LuaRocks is currently running on queried platform.
 function is_platform(query)
    assert(type(query) == "string")
 
-   query = "^" .. query:lower()
-   for index, platform in ipairs(platforms) do
-      if platform:match(query) then
-         return index, platform
+   for _, platform in ipairs(platforms) do
+      if platform == query then
+         return true
       end
    end
-   if system:lower():match(query) then
-      return #platforms + 1, system
-   end
 end
diff --git a/src/luarocks/deps.lua b/src/luarocks/deps.lua
@@ -391,6 +391,27 @@ function match_deps(rockspec, blacklist, deps_mode)
    return matched, missing, no_upgrade
 end
 
+--- Match a platform dependency to the system name and version
+-- @param plat string: A platform dependency as a string.
+-- @return number, string: The index and name of the platform type
+-- that was successfully matched against. The index is from the
+-- cfg.platforms list or one past the length for the canonical
+-- system name cfg.system.
+function match_platform(plat)
+   assert(type(plat) == "string")
+
+   local plat_dep, err = parse_dep(plat)
+   if not plat_dep then return nil, err end
+   for index, platform in ipairs(cfg.platforms) do
+      if platform == plat_dep.name then
+         return index, platform
+      end
+   end
+   if cfg.system:lower():match("^"..plat_dep.name:lower()) then
+      return #cfg.platforms + 1, cfg.system
+   end
+end
+
 --- Return a set of values of a table.
 -- @param tbl table: The input table.
 -- @return table: The array of keys.
@@ -422,22 +443,22 @@ function fulfill_dependencies(rockspec, deps_mode)
       for _, plat in pairs(rockspec.supported_platforms) do
          local neg, plat = plat:match("^(!?)(.*)")
          if neg == "!" then
-            if platforms_set[plat] then
-               return nil, "This rockspec for "..rockspec.package.." does not support "..plat.." platforms."
+            local ix, plat_name = match_platform(plat)
+            if ix then
+               return nil, "This rockspec for "..rockspec.package.." does not support "..plat_name.." platforms."
             end
          else
-            if platforms_set[plat] then
-               supported = true
-            else
-               if supported == nil then
+            if supported ~= true then
+               if match_platform(plat) then
+                  supported = true
+               else
                   supported = false
                end
             end
          end
       end
       if supported == false then
-         local plats = table.concat(cfg.platforms, ", ")
-         return nil, "This rockspec for "..rockspec.package.." does not support "..plats.." platforms."
+         return nil, "This rockspec for "..rockspec.package.." does not support "..cfg.system.." platforms."
       end
    end
 

diff --git a/src/luarocks/util.lua b/src/luarocks/util.lua
@@ -157,13 +157,14 @@ function platform_overrides(tbl)
    assert(type(tbl) == "table" or not tbl)
 
    local cfg = require("luarocks.cfg")
+   local deps = require("luarocks.deps")
 
    if not tbl then return end
 
    if tbl.platforms then
       local platform_order = {}
       for query, platform_tbl in pairs(tbl.platforms) do
-         local index = cfg.is_platform(query)
+         local index = deps.match_platform(query)
          if index then
             platform_order[index] = platform_tbl
          end