cgir: remove the legacy CGIR variant (nim-lang#1234)

## Summary All code generators use the new goto-using variant of the CGIR now, rendering the legacy variant obsolete. This is an internal-only refactoring. ## Details * remove the `cgirgen_legacy` module * remove the node kinds belonging to the legacy variant * remove the sets introduced for the transition * remove some leftover usages of `cnkStmtListExpr` (they were dead code already)
Clyybber · Mar 13, 2024 · 0d03576 · 0d03576
1 parent f3f83e7
commit 0d03576
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Showing 9 changed files with 17 additions and 976 deletions.
diff --git a/compiler/backend/backends.nim b/compiler/backend/backends.nim
@@ -15,8 +15,7 @@ import
   compiler/backend/[
     cgmeth,
     cgir,
-    cgirgen,
-    cgirgen_legacy
+    cgirgen
   ],
   compiler/front/[
     msgs,
@@ -371,13 +370,6 @@ proc generateIR*(graph: ModuleGraph, idgen: IdGenerator, env: MirEnv,
   result = cgirgen.generateIR(graph, idgen, env, owner, body)
   echoOutput(graph.config, owner, result)
 
-proc generateIRLegacy*(graph: ModuleGraph, idgen: IdGenerator, env: MirEnv,
-                 owner: PSym, body: sink MirBody): Body =
-  ## Translates the MIR code provided by `code` into legacy ``CgNode`` IR and,
-  ## if enabled, echoes the result.
-  result = cgirgen_legacy.generateIR(graph, idgen, env, owner, body)
-  echoOutput(graph.config, owner, result)
-
 # ------- handling of lifted globals ---------
 
 proc produceFragmentsForGlobals(

diff --git a/compiler/backend/ccgexprs.nim b/compiler/backend/ccgexprs.nim
@@ -2130,8 +2130,8 @@ proc expr(p: BProc, n: CgNode, d: var TLoc) =
   of cnkJoinStmt, cnkGotoStmt:
     unreachable("handled separately")
   of cnkInvalid, cnkType, cnkAstLit, cnkMagic, cnkRange, cnkBinding, cnkBranch,
-     cnkLabel, cnkTargetList, cnkStmtListExpr, cnkField, cnkStmtList,
-     cnkLeave, cnkResume, cnkLegacyNodes:
+     cnkLabel, cnkTargetList, cnkField, cnkStmtList,
+     cnkLeave, cnkResume:
     internalError(p.config, n.info, "expr(" & $n.kind & "); unknown node kind")
 
 proc getDefaultValue(p: BProc; typ: PType; info: TLineInfo): Rope =

diff --git a/compiler/backend/cgir.nim b/compiler/backend/cgir.nim
@@ -105,30 +105,23 @@ type
                      ## different type
 
     cnkStmtList
-    cnkStmtListExpr
-    # XXX: both stmtlist and stmtlistexpr are obsolete. They're only kept for
-    #      grouping the top-level statements under a single node
+    # XXX: stmtlist is obsolete, and only kept temporarily to group statements
+    #      together under a single node
 
     cnkVoidStmt   ## discard the operand value (i.e., do nothing with it)
     cnkEmitStmt   ## an ``emit`` statement
     cnkAsmStmt    ## an ``asm`` statement
 
     cnkIfStmt     ## only execute the body when the condition expression
                   ## evaluates to 'true'
-    cnkRepeatStmt ## execute the body indefinitely
     cnkCaseStmt   ## a ``case`` statement
     cnkBranch     ## the branch of a ``case`` statement
-    cnkBlockStmt  ## an (optionally) labeled block
-    cnkTryStmt
 
     cnkGotoStmt
     cnkLoopStmt   ## jump back to a loop join point
-    cnkBreakStmt  ## break out of labeled block, or, if no label is provided,
-                  ## the closest ``repeat`` loop
     cnkRaiseStmt  ## raise(x) -- set the `x` as the current exception and start
                   ## exceptional control-flow. `x` can be ``cnkEmpty`` in which
                   ## case "set current exception" part is skipped
-    cnkReturnStmt
     cnkContinueStmt## jump to the next target in the active jump list
 
     cnkJoinStmt   ## join point for gotos
@@ -155,19 +148,12 @@ const
   cnkWithOperand*  = {cnkConv, cnkHiddenConv, cnkDeref, cnkAddr, cnkHiddenAddr,
                       cnkDerefView, cnkObjDownConv, cnkObjUpConv, cnkCast,
                       cnkLvalueConv}
-  cnkAtoms*        = {cnkInvalid..cnkResume, cnkReturnStmt}
+  cnkAtoms*        = {cnkInvalid..cnkResume}
     ## node kinds that denote leafs
   cnkWithItems*    = AllKinds - cnkWithOperand - cnkAtoms
     ## node kinds for which the ``items`` iterator is available
 
   cnkLiterals* = {cnkIntLit, cnkUIntLit, cnkFloatLit, cnkStrLit}
-  cnkLegacyNodes* = {cnkBlockStmt, cnkTryStmt, cnkReturnStmt, cnkBreakStmt,
-                     cnkRepeatStmt}
-    ## node kinds that belong to the legacy control-flow representation
-  cnkNewCfNodes* = {cnkGotoStmt, cnkJoinStmt, cnkLeave, cnkResume,
-                    cnkContinueStmt, cnkLoopStmt, cnkLoopJoinStmt,
-                    cnkEnd, cnkTargetList}
-    ## node kinds that belong to the new-style control-flow representation
 
 type
   Local* = object
@@ -199,7 +185,7 @@ type
     info*: TLineInfo
     typ*: PType
     case kind*: CgNodeKind
-    of cnkInvalid, cnkEmpty, cnkType, cnkNilLit, cnkReturnStmt, cnkResume:
+    of cnkInvalid, cnkEmpty, cnkType, cnkNilLit, cnkResume:
       discard
     of cnkIntLit, cnkUIntLit:
       # future direction: use a ``BiggestUint`` for uint values