1 files changed, 69 insertions, 0 deletions
diff --git a/CIAO/tests/IDL3/ImpliedIDL/All/README b/CIAO/tests/IDL3/ImpliedIDL/All/README
new file mode 100644
index 00000000000..fe43b62b221
--- /dev/null
+++ b/CIAO/tests/IDL3/ImpliedIDL/All/README
@@ -0,0 +1,69 @@
+                            Converting IDL3 to IDL2
+                            =======================
+                            
+Introduction
+============
+
+This directory contains a test for the executable
+tao_idl3_to_idl2, which inputs a single IDL file and
+outputs a single IDL file which has the IDL3 declarations
+from the input file converted to the corresponding 'implied
+IDL' declarations specificed by the mapping in the CCM
+document.
+
+This utility can be used in conjunction with some IDL compiler
+that does not support IDL3 keywords and syntax. The output of
+the utility can be processed by such a compiler, yielding code
+in the target programming language equivalent to that which
+would have been generated in one step by a CCM-aware IDL compiler.
+
+The tao_idl3_to_idl2 executable itself is built in
+CIAO_ROOT/tools/IDL3_to_IDL2. It uses the TAO IDL compiler
+front end parsing engine and the TAO IDL compiler driver
+files, so it depends on ACE. The IDL generation is 
+accomplished by a custom backend library.
+
+Running The Test
+================
+
+This test is only to determine that the generated IDL files
+are valid. So once the converted IDL file (having the
+extension _IDL2.idl) is generated by tao_idl3_to_idl2, the
+TAO IDL compiler is executed on the generated IDL file and
+the resulting C++ files compiled. If the compilation is
+successful for all such files, the test is a success.
+
+Notable Build Features
+======================
+
+Two features of the MPC file for this test are of interest:
+
+1.
+Two of the three IDL files in the test, pass_through.idl and
+include.idl, contain no IDL3 constructs, but merely test the
+executable's regeneration of IDL2 constructs. Since one IDL
+file is included in the other, there is a dependency that
+requires both IDL files to be processed before running the
+IDL compiler on pass_through_IDL2.idl. The line
+
+    pass_through_IDL2.idl << include_IDL2.idl
+
+indicates this dependency to the MPC tool, ensuring the correct
+order of execution.
+
+2.
+The -Sm option passed to the IDL compiler must be used when
+processing an IDL file resulting from the execution of
+tao_idl3_to_idl2. This option disables the action of the 
+tao_idl backend 'preprocessor' (which is 'on' by default)
+that adds implied IDL nodes to the Abstract Syntax Tree
+for subsequent C++ code generation. In the case of an eventtype,
+the CCM spec requires additional code generation for a corresponding
+implied 'event consumer' IDL interface, as well as for the
+eventtype itself. The tao_idl3_to_idl2 executable adds this
+interface explicitly to the generated IDL file, along with the
+original eventtype. Without the -Sm option, the event consumer
+interface would appear redundantly in both explicit and implied
+IDL, resulting in a name clash. Since the IDL compiler cannot
+know the origin of the IDL file it is processing, the -Sm
+option encapsulates that knowledge.
+\ No newline at end of file