builtin: auto-detect modules when build.modules (or build!) is absent

5 files changed, 137 insertions, 56 deletions

diff --git a/spec/build_spec.lua b/spec/build_spec.lua
index b703478e..af2dfe38 100644
--- a/spec/build_spec.lua
+++ b/spec/build_spec.lua
@@ -269,6 +269,48 @@ describe("LuaRocks build tests #integration", function()
          assert.truthy(run.luarocks_bool("build " .. rockspec))
          assert.is.truthy(run.luarocks("show a_rock"))
       end)
+
+      it("'builtin' detects lua files if modules are not given", function()
+         local rockspec = "autodetect-1.0-1.rockspec"
+         test_env.write_file(rockspec, [[
+            rockspec_format = "3.0"
+            package = "autodetect"
+            version = "1.0-1"
+            source = {
+               url = "file://]] .. testing_paths.fixtures_dir .. [[/autodetect/bla.lua"
+            }
+            description = {
+               summary = "An example rockspec",
+            }
+            dependencies = {
+               "lua >= 5.1"
+            }
+            build = {
+            }
+         ]], finally)
+         assert.truthy(run.luarocks_bool("build " .. rockspec))
+         assert.match("bla.lua", run.luarocks("show autodetect"))
+      end)
+
+      it("'builtin' detects lua files if build is not given", function()
+         local rockspec = "autodetect-1.0-1.rockspec"
+         test_env.write_file(rockspec, [[
+            rockspec_format = "3.0"
+            package = "autodetect"
+            version = "1.0-1"
+            source = {
+               url = "file://]] .. testing_paths.fixtures_dir .. [[/autodetect/bla.lua"
+            }
+            description = {
+               summary = "An example rockspec",
+            }
+            dependencies = {
+               "lua >= 5.1"
+            }
+         ]], finally)
+         assert.truthy(run.luarocks_bool("build " .. rockspec))
+         assert.match("bla.lua", run.luarocks("show autodetect"))
+      end)
    end)
 
    describe("#mock external dependencies", function()
diff --git a/spec/fixtures/autodetect/bla.lua b/spec/fixtures/autodetect/bla.lua
new file mode 100644
index 00000000..a5647075
--- /dev/null
+++ b/spec/fixtures/autodetect/bla.lua
@@ -0,0 +1 @@
+return {}
diff --git a/src/luarocks/build.lua b/src/luarocks/build.lua
index ac4ecfad..0cfbccd7 100644
--- a/src/luarocks/build.lua
+++ b/src/luarocks/build.lua
@@ -353,7 +353,13 @@ function build.build_rockspec(rockspec, opts)
    assert(opts:type() == "build.opts")
 
    if not rockspec.build then
-      return nil, "Rockspec error: build table not specified"
+      if rockspec:format_is_at_least("3.0") then
+         rockspec.build = {
+            type = "builtin"
+         }
+      else
+         return nil, "Rockspec error: build table not specified"
+      end
    end
 
    if not rockspec.build.type then
diff --git a/src/luarocks/build/builtin.lua b/src/luarocks/build/builtin.lua
index 41cc31b0..4ff59f8b 100644
--- a/src/luarocks/build/builtin.lua
+++ b/src/luarocks/build/builtin.lua
@@ -10,6 +10,85 @@ local util = require("luarocks.util")
 local cfg = require("luarocks.core.cfg")
 local dir = require("luarocks.dir")
 
+local function autoextract_libs(external_dependencies, variables)
+   if not external_dependencies then
+      return nil, nil, nil
+   end
+   local libs = {}
+   local incdirs = {}
+   local libdirs = {}
+   for name, data in pairs(external_dependencies) do
+      if data.library then
+         table.insert(libs, data.library)
+         table.insert(incdirs, variables[name .. "_INCDIR"])
+         table.insert(libdirs, variables[name .. "_LIBDIR"])
+      end
+   end
+   return libs, incdirs, libdirs
+end
+
+do
+   local function get_cmod_name(file)
+      local fd = io.open(dir.path(fs.current_dir(), file), "r")
+      if not fd then return nil end
+      local data = fd:read("*a")
+      fd:close()
+      return (data:match("int%s+luaopen_([a-zA-Z0-9_]+)"))
+   end
+
+   local luamod_blacklist = {
+      test = true,
+      tests = true,
+   }
+
+   function builtin.autodetect_modules(libs, incdirs, libdirs)
+      local modules = {}
+      local copy_directories
+
+      local prefix = ""
+      for _, parent in ipairs({"src", "lua"}) do
+         if fs.is_dir(parent) then
+            fs.change_dir(parent)
+            prefix = parent.."/"
+            break
+         end
+      end
+
+      for _, file in ipairs(fs.find()) do
+         local luamod = file:match("(.*)%.lua$")
+         if luamod and not luamod_blacklist[luamod] then
+            modules[path.path_to_module(file)] = prefix..file
+         else
+            local cmod = file:match("(.*)%.c$")
+            if cmod then
+               local modname = get_cmod_name(file) or path.path_to_module(file:gsub("%.c$", ".lua"))
+               modules[modname] = {
+                  sources = prefix..file,
+                  libraries = libs,
+                  incdirs = incdirs,
+                  libdirs = libdirs,
+               }
+            end
+         end
+      end
+
+      for _, directory in ipairs({ "doc", "docs", "samples", "tests" }) do
+         if fs.is_dir(directory) then
+            if not copy_directories then
+               copy_directories = {}
+            end
+            table.insert(copy_directories, directory)
+         end
+      end
+
+      if prefix ~= "" then
+         fs.pop_dir()
+      end
+
+      return modules, copy_directories
+   end
+end
+
 --- Run a command displaying its execution on standard output.
 -- @return boolean: true if command succeeds (status code 0), false
 -- otherwise.
@@ -140,7 +219,12 @@ function builtin.run(rockspec)
    local libdir = path.lib_dir(rockspec.name, rockspec.version)
    
    if not build.modules then
-      return nil, "Missing build.modules table"
+      if rockspec:format_is_at_least("3.0") then
+         local libs, incdirs, libdirs = autoextract_libs(rockspec.external_dependencies, rockspec.variables)
+         build.modules = builtin.autodetect_modules(libs, incdirs, libdirs)
+      else
+         return nil, "Missing build.modules table"
+      end
    end
    for name, info in pairs(build.modules) do
       local moddir = path.module_to_path(name)
diff --git a/src/luarocks/cmd/write_rockspec.lua b/src/luarocks/cmd/write_rockspec.lua
index 36beffd0..b4007e85 100644
--- a/src/luarocks/cmd/write_rockspec.lua
+++ b/src/luarocks/cmd/write_rockspec.lua
@@ -1,11 +1,11 @@
 
 local write_rockspec = {}
 
+local builtin = require("luarocks.build.builtin")
 local cfg = require("luarocks.core.cfg")
 local dir = require("luarocks.dir")
 local fetch = require("luarocks.fetch")
 local fs = require("luarocks.fs")
-local path = require("luarocks.path")
 local persist = require("luarocks.persist")
 local rockspecs = require("luarocks.rockspecs")
 local type_rockspec = require("luarocks.type.rockspec")
@@ -172,31 +172,8 @@ local function check_license()
    return nil, data
 end
 
-local function get_cmod_name(file)
-   local fd = open_file(file)
-   if not fd then return nil end
-   local data = fd:read("*a")
-   fd:close()
-   return (data:match("int%s+luaopen_([a-zA-Z0-9_]+)"))
-end
-
-local luamod_blacklist = {
-   test = true,
-   tests = true,
-}
-
 local function fill_as_builtin(rockspec, libs)
    rockspec.build.type = "builtin"
-   rockspec.build.modules = {}
-   local prefix = ""
-
-   for _, parent in ipairs({"src", "lua"}) do
-      if fs.is_dir(parent) then
-         fs.change_dir(parent)
-         prefix = parent.."/"
-         break
-      end
-   end
 
    local incdirs, libdirs
    if libs then
@@ -207,37 +184,8 @@ local function fill_as_builtin(rockspec, libs)
          libdirs[#libdirs+1] = "$("..upper.."_LIBDIR)"
       end
    end
-
-   for _, file in ipairs(fs.find()) do
-      local luamod = file:match("(.*)%.lua$")
-      if luamod and not luamod_blacklist[luamod] then
-         rockspec.build.modules[path.path_to_module(file)] = prefix..file
-      else
-         local cmod = file:match("(.*)%.c$")
-         if cmod then
-            local modname = get_cmod_name(file) or path.path_to_module(file:gsub("%.c$", ".lua"))
-            rockspec.build.modules[modname] = {
-               sources = prefix..file,
-               libraries = libs,
-               incdirs = incdirs,
-               libdirs = libdirs,
-            }
-         end
-      end
-   end
    
-   for _, directory in ipairs({ "doc", "docs", "samples", "tests" }) do
-      if fs.is_dir(directory) then
-         if not rockspec.build.copy_directories then
-            rockspec.build.copy_directories = {}
-         end
-         table.insert(rockspec.build.copy_directories, directory)
-      end
-   end
-   
-   if prefix ~= "" then
-      fs.pop_dir()
-   end
+   rockspec.build.modules, rockspec.build.copy_directories = builtin.autodetect_modules(libs, incdirs, libdirs)
 end
 
 local function rockspec_cleanup(rockspec)