[FIRRTL] Generate docs for each ODS file

Change the way FIRRTL ODS documentation is generated to manually run
each file through mlir-tblgen.  This is primarily done to enable more
cleanly adding documentation about OpInterfaces and to remove
information about type constraints (which are ephemeral and do not
appear in the generated C++).

Note that this currently produces buggy Markdown for OpInterfaces with a
defined function body.  This will be fixed by:

  - https://reviews.llvm.org/D140590

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>

docs/Dialects/FIRRTL/_index.md

@@ -1,3 +1,34 @@
 # 'firrtl' Dialect
 
-[include "Dialects/FIRRTL.md"]
+This dialect defines the `firrtl` dialect, which is used to lower from Chisel
+code to Verilog.  For more information, see the [FIRRTL GitHub
+page](https://github.com/freechipsproject/firrtl).
+
+[TOC]
+
+## Operation Definitions -- Structure
+
+[include "Dialects/FIRRTLStructureOps.md"]
+
+## Operation Definitions -- Declarations
+
+[include "Dialects/FIRRTLDeclarationOps.md"]
+
+## Statement Operation -- Statements
+
+[include "Dialects/FIRRTLStatementOps.md"]
+
+## Operation Definitions -- Expressions
+
+[include "Dialects/FIRRTLExpressionOps.md"]
+
+## Type Definitions
+
+[include "Dialects/FIRRTLTypes.md"]
+[include "Dialects/FIRRTLTypesImpl.md"]
+
+## Attribute Definitions
+
+[include "Dialects/FIRRTLAttributes.md"]
+
+[include "Dialects/FIRRTLOpInterfaces.md"]

include/circt/Dialect/FIRRTL/CMakeLists.txt

@@ -1,6 +1,5 @@
 # FIRRTL
 add_circt_dialect(FIRRTL firrtl FIRRTL)
-add_circt_dialect_doc(FIRRTL firrtl)
 
 set(LLVM_TARGET_DEFINITIONS FIRRTL.td)
 mlir_tablegen(FIRRTLEnums.h.inc -gen-enum-decls)
@@ -12,7 +11,6 @@ add_public_tablegen_target(CIRCTFIRRTLEnumsIncGen)
 set(LLVM_TARGET_DEFINITIONS Passes.td)
 mlir_tablegen(Passes.h.inc -gen-pass-decls)
 add_public_tablegen_target(CIRCTFIRRTLTransformsIncGen)
-add_circt_doc(Passes FIRRTLPasses -gen-pass-doc)
 
 set(LLVM_TARGET_DEFINITIONS FIRRTLCanonicalization.td)
 mlir_tablegen(FIRRTLCanonicalization.h.inc -gen-rewriters)
@@ -24,6 +22,19 @@ mlir_tablegen(FIRRTLOpInterfaces.cpp.inc -gen-op-interface-defs)
 add_public_tablegen_target(CIRCTFIRRTLOpInterfacesIncGen)
 add_dependencies(circt-headers CIRCTFIRRTLOpInterfacesIncGen)
 
+# Generate Dialect documentation.
+add_circt_doc(FIRRTLAttributes Dialects/FIRRTLAttributes -gen-attrdef-doc)
+add_circt_doc(FIRRTLStructure Dialects/FIRRTLStructureOps -gen-op-doc)
+add_circt_doc(FIRRTLDeclarations Dialects/FIRRTLDeclarationOps -gen-op-doc)
+add_circt_doc(FIRRTLStatements Dialects/FIRRTLStatementOps -gen-op-doc)
+add_circt_doc(FIRRTLExpressions Dialects/FIRRTLExpressionOps -gen-op-doc)
+add_circt_doc(FIRRTLTypes Dialects/FIRRTLTypes -gen-typedef-doc)
+add_circt_doc(FIRRTLTypesImpl Dialects/FIRRTLTypesImpl -gen-typedef-doc)
+add_circt_doc(FIRRTLOpInterfaces Dialects/FIRRTLOpInterfaces -gen-op-interface-docs)
+
+# Generate Pass documentation.
+add_circt_doc(Passes FIRRTLPasses -gen-pass-doc)
+
 # CHIRRTL
 add_circt_dialect(CHIRRTL chirrtl CHIRRTL)
 add_circt_dialect_doc(CHIRRTL chirrtl)

include/circt/Dialect/FIRRTL/FIRRTLDialect.td

@@ -25,9 +25,9 @@ def FIRRTLDialect : Dialect {
 
   let summary = "Types and operations for firrtl dialect";
   let description = [{
-    This dialect defines the `firrtl` dialect, which is used to lower from
-    Chisel code to Verilog.  For more information, see the
-    [FIRRTL GitHub page](https://github.com/freechipsproject/firrtl).
+    This dialect defines the `firrtl` dialect, which is used to lower from Chisel
+    code to Verilog.  For more information, see the [FIRRTL GitHub
+    page](https://github.com/freechipsproject/firrtl).
   }];
 
   let hasConstantMaterializer = 1;