export of omake

omake/OMakefile

@@ -0,0 +1,7 @@
+export1(foo) =
+  eprintln(foo=$(foo))
+  export # argument is exported to the outside!!!
+
+export1(a)
+eprintln(foo=$(foo))
+

omake/OMakeroot

@@ -0,0 +1,45 @@
+########################################################################
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this file, to deal in the File without
+# restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the File, and to permit persons to whom the
+# File is furnished to do so, subject to the following condition:
+#
+# THE FILE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE FILE OR
+# THE USE OR OTHER DEALINGS IN THE FILE.
+
+########################################################################
+# The standard OMakeroot file.
+# You will not normally need to modify this file.
+# By default, your changes should be placed in the
+# OMakefile in this directory.
+#
+# If you decide to modify this file, note that it uses exactly
+# the same syntax as the OMakefile.
+#
+
+#
+# Include the standard installed configuration files.
+# Any of these can be deleted if you are not using them,
+# but you probably want to keep the Common file.
+#
+open build/C
+open build/OCaml
+open build/LaTeX
+
+#
+# The command-line variables are defined *after* the
+# standard configuration has been loaded.
+#
+DefineCommandVars()
+
+#
+# Include the OMakefile in this directory.
+#
+.SUBDIRS: .

omake_points.md

@@ -102,3 +102,34 @@ hello.c:
         eprintln($(FP))         # 1 !!!
         echo "hello" > hello.c
 ```
+
+# 引数なしの `export`
+
+引数なしの `export` が外に export する変数やルールをちゃんと理解する事が重要
+
+* 全ての動的スコープの変数の値
+* カレントディレクトリ
+* Unix環境変数
+* 現在の implicit rule や implicit dependencies
+* 現在の "phony" ターゲット宣言
+
+特に関数引数の名前が外に漏れ出るのが非常に困る。これが理由で `omake` 使えないと言われても仕方がない:
+
+```
+export1(foo) =
+  eprintln(foo=$(foo)) # foo=a
+  export # argument is exported to the outside!!!
+
+export1(a)
+eprintln(foo=$(foo)) # foo=a !!!
+```
+
+# 引数ありの `export`
+
+引数がある `export` はその引数を評価後、その引数によって
+
+* 値が空なら引数無し `export` と同じ
+* `$(export 変数..)` で作られた環境の場合、その環境
+* `.RULE`: implicit rules and implicit dependencies.
+* `.PHONY`: the set of “phony” target declarations.
+* その他の文字列は変数名として扱いその変数を export する