[Git][ghc/ghc][wip/nr/typed-wasm-control-flow] 2 commits: move code that renders WebAssembly control flow to assembly

[Norman Ramsey (@nrnrnr)]

Norman Ramsey pushed to branch wip/nr/typed-wasm-control-flow at Glasgow Haskell Compiler / GHC


Commits:
44c37f94 by Norman Ramsey at 2022-08-09T13:00:38-04:00
move code that renders WebAssembly control flow to assembly

- - - - -
4c22c583 by Norman Ramsey at 2022-08-09T13:01:01-04:00
make WebAssembly -> .s higher order

- - - - -


2 changed files:

- compiler/GHC/Wasm/Builder.hs → compiler/GHC/Wasm/ControlFlow/ToAsm.hs
- compiler/ghc.cabal.in


Changes:

=====================================
compiler/GHC/Wasm/Builder.hs → compiler/GHC/Wasm/ControlFlow/ToAsm.hs
=====================================
@@ -1,9 +1,10 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
-module GHC.Wasm.Builder
-  ( toIndented
-  , MyExpr(..), MyActions(..)
+module GHC.Wasm.ControlFlow.ToAsm
+  ( toIndentedAsm
+  , noIndentation
   )
 where
 
@@ -21,11 +22,14 @@ import GHC.Utils.Panic
 
 import GHC.Wasm.ControlFlow hiding ((<>))
 
-defaultIndent :: Builder
+type Indentation = Builder
+
+defaultIndent :: Indentation
 defaultIndent = "  "
 
-toIndented :: WasmControl MyActions MyExpr pre post -> Builder
-toIndented s = printWithIndent mempty s <> "\n"
+noIndentation :: Indentation
+noIndentation = ""
+
 
 wasmFunctionType :: WasmFunctionType pre post -> Builder
 wasmFunctionType (WasmFunctionType TypeListNil TypeListNil) = ""
@@ -37,41 +41,48 @@ tagBuilder TagI32 = "i32"
 tagBuilder TagF32 = "f32"
 
 
-printWithIndent :: Builder -> WasmControl MyActions MyExpr pre post -> Builder
-printWithIndent indent s = print s
-  where print, outdent :: WasmControl MyActions MyExpr pre post -> Builder
+type Printer a = Indentation -> a -> Builder
+
+-- | Converts WebAssembly control-flow code into GNU (Clang) assembly
+-- syntax, indented for readability.  For ease of combining with other
+-- output, the result does not have a trailing newline.
+--
+-- Initial `Indentation` argument gives the indentation of the entire output;
+-- for most use cases it will likely be `mempty`.
+
+toIndentedAsm :: forall s e pre post
+               . Printer s -> Printer e -> Printer (WasmControl s e pre post)
+toIndentedAsm ps pe indent s = print s
+  where print, shift :: WasmControl s e pre' post' -> Builder
         newline :: Builder -> Builder -> Builder
         (<+>) :: Builder -> Builder -> Builder
         ty = wasmFunctionType
 
+        -- cases meant to avoid generating any output for `WasmFallthrough`
         print (WasmFallthrough `WasmSeq` s) = print s
         print (s `WasmSeq` WasmFallthrough) = print s
         print (WasmIfTop t s WasmFallthrough) =
-            "br_if" <+> ty t `newline` outdent s `newline` "end_if"
+            "br_if" <+> ty t `newline` shift s `newline` "end_if"
         print (WasmIfTop t WasmFallthrough s) =
-            "br_if" <+> ty t `newline` "else" `newline` outdent s `newline` "end_if"
-
-        print (WasmPush _ _) = "i32.const 42"
-        print (WasmBlock t s) = "block" <+> ty t `newline` outdent s `newline` "end_block"
-        print (WasmLoop  t s) = "loop"  <+> ty t `newline` outdent s `newline` "end_loop"
-        print (WasmIfTop t ts fs) = "if" <+> ty t `newline` outdent ts `newline`
-                                    "else" `newline` outdent fs `newline` "end_if"
+            "br_if" <+> ty t `newline` "else" `newline` shift s `newline` "end_if"
+
+        -- normal cases
+        print (WasmPush _ e) = pe indent e
+        print (WasmBlock t s) = "block" <+> ty t `newline` shift s `newline` "end_block"
+        print (WasmLoop  t s) = "loop"  <+> ty t `newline` shift s `newline` "end_loop"
+        print (WasmIfTop t ts fs) = "if" <+> ty t `newline` shift ts `newline`
+                                    "else" `newline` shift fs `newline` "end_if"
         print (WasmBr l) = "br" <+> BS.intDec l
         print (WasmBrTable e _ ts t) =
-          myExpr e `newline` "br_table {" <+>
+          pe indent e `newline` "br_table {" <+>
           mconcat (intersperse ", " [BS.intDec i | i <- ts <> [t]]) <+>
           "}"
         print (WasmReturnTop _) = "return"
-        print (WasmActions as) = myActions as
+        print (WasmActions as) = ps indent as
         print (s `WasmSeq` s') = print s `newline` print s'
 
         print WasmFallthrough = "// fallthrough" -- hopefully rare
 
         newline s s' = s <> "\n" <> indent <> s'
-        outdent s = defaultIndent <> printWithIndent (indent <> defaultIndent) s
+        shift s = defaultIndent <> toIndentedAsm ps pe (indent <> defaultIndent) s
         s <+> s' = s <> " " <> s'
-
-
-newtype MyExpr = MyExpr { myExpr :: Builder  }
-
-newtype MyActions = MyActions { myActions :: Builder }


=====================================
compiler/ghc.cabal.in
=====================================
@@ -805,9 +805,9 @@ Library
         GHC.Utils.Ppr.Colour
         GHC.Utils.TmpFs
         GHC.Utils.Trace
-        GHC.Wasm.Builder
         GHC.Wasm.ControlFlow
         GHC.Wasm.ControlFlow.FromCmm
+        GHC.Wasm.ControlFlow.ToAsm
 
         Language.Haskell.Syntax
         Language.Haskell.Syntax.Basic



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/c5c029678376197ddd365ba2665c361dd908502d...4c22c583c64f5a15c13080f3aaa5701a6a909c7c

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/c5c029678376197ddd365ba2665c361dd908502d...4c22c583c64f5a15c13080f3aaa5701a6a909c7c
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