Implement notion of a "container format" (#213)

The big addition here is that the Slang "bytecode" is no longer treated as just a "code generation target" (`CodeGenTarget`) akin to DX bytecode (DXBC) or SPIR-V, but instead is a `ContainerFormat` that can be used to emit all the results of a compile request (well, currently just the IR-as-BC, but the intention is there).

Getting to this goal involved some prior checkins that eliminated bogus "targets" that weren't really akin to SPIR-V or DXBC: `-target slang-ir-asm` and `-target reflection-json`. Those targets were really in place to support testing, and so they've been made more explicit testing/debug options.

This change eliminates `-target slang-ir` and instead tries to allow the user to specify `-o foo.slang-module` as an output file name, that indicates the intention to output a "container" file that will wrap up all the generated code.

I've also gone ahead and generalized the existing `-target` option so that we are actually building up a *list* of code generation targets. This is largely just a cleanup, since it forces code to be more aware of when it is doing something target-specific vs. target independent. For example, reflection layout information lives on a requested target, and not on the compile request as a whole, and similarly output code is per-target, per-entry-point.

As a cleanup, I eliminated support for per-translation-unit output. This was vestigial code from back when I used to try and do HLSL generation for a whole translation unit instead of per-entry-point (which turned out to be a lot of complexity for little gain), and it was only being used in the `hello` example and the `render-test` test fixture - in both cases fixing it up was easy enough. I've stubbed out the old `spGetTranslationUnitSource` API, but haven't removed it yet.

1 files changed, 0 insertions, 19 deletions

diff --git a/source/slangc/main.cpp b/source/slangc/main.cpp
index 7c57fa8a9..391642c3e 100644
--- a/source/slangc/main.cpp
+++ b/source/slangc/main.cpp
@@ -66,25 +66,6 @@ int MAIN(int argc, char** argv)
             exit(-1);
         }
 
-#if 0
-        // Produce output as the command-line compiler driver should.
-
-        // Now dump the output from the compilation to stdout.
-        //
-        // TODO: Need a way to control where output goes so that
-        // we can actually use the standalone compiler as something
-        // more than a testing tool.
-        //
-
-        int translationUnitCount = spGetTranslationUnitCount(compileRequest);
-        for(int tt = 0; tt < translationUnitCount; ++tt)
-        {
-            auto output = spGetTranslationUnitSource(compileRequest, tt);
-            fputs(output, stdout);
-        }
-        fflush(stdout);
-#endif
-
         // Now that we are done, clean up after ourselves
 
         spDestroyCompileRequest(compileRequest);