[FIRRTL] Support "invalidate <mem, instance>"

Add support for invalidation syntax that invalidates an instance or a
memory.  This was never technically supported before, though it should
have been.  Previously, this was only supported through the "is invalid"
path which is has been deprecated for FIRRTL versions >=3.

Fixes #7730.

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

lib/Dialect/FIRRTL/Import/FIRParser.cpp

@@ -3960,7 +3960,52 @@ ParseResult FIRStmtParser::parseInvalidate() {
   auto startTok = consumeToken(FIRToken::kw_invalidate);
 
   Value lhs;
-  if (parseExp(lhs, "expected connect expression") || parseOptionalInfo())
+
+  StringRef id;
+  auto loc = getToken().getLoc();
+  SymbolValueEntry symtabEntry;
+  if (parseId(id, "expected static reference expression") ||
+      moduleContext.lookupSymbolEntry(symtabEntry, id, loc))
+    return failure();
+
+  // If we looked up a normal value (e.g., wire, register, or port), then we
+  // just need to get any optional trailing expression.  Invalidate this.
+  if (!moduleContext.resolveSymbolEntry(lhs, symtabEntry, loc, false)) {
+    if (parseOptionalExpPostscript(lhs, /*allowDynamic=*/false) ||
+        parseOptionalInfo())
+      return failure();
+
+    locationProcessor.setLoc(startTok.getLoc());
+    emitInvalidate(lhs);
+    return success();
+  }
+
+  // We're dealing with an instance.  This instance may or may not have a
+  // trailing expression.  Handle the special case of no trailing expression
+  // first by invalidating all of its results.
+  assert(symtabEntry.is<UnbundledID>() && "should be an instance");
+
+  if (getToken().isNot(FIRToken::period)) {
+    locationProcessor.setLoc(loc);
+    // Invalidate all of the results of the bundled value.
+    unsigned unbundledId = symtabEntry.get<UnbundledID>() - 1;
+    UnbundledValueEntry &ubEntry = moduleContext.getUnbundledEntry(unbundledId);
+    for (auto elt : ubEntry)
+      emitInvalidate(elt.second);
+    return success();
+  }
+
+  // Handle the case of an instance with a trailing expression.  This must begin
+  // with a '.' (until we add instance arrays).
+  StringRef fieldName;
+  if (parseToken(FIRToken::period, "expected '.' in field reference") ||
+      parseFieldId(fieldName, "expected field name") ||
+      moduleContext.resolveSymbolEntry(lhs, symtabEntry, fieldName, loc))
+    return failure();
+
+  // Update with any trailing expression and invalidate it.
+  if (parseOptionalExpPostscript(lhs, /*allowDynamic=*/false) ||
+      parseOptionalInfo())
     return failure();
 
   locationProcessor.setLoc(startTok.getLoc());

test/Dialect/FIRRTL/SFCTests/directories.fir

@@ -29,10 +29,8 @@ circuit TestHarness:
       write-latency => 1
       read-under-write => undefined
 
-    invalidate foo_m.r
-    invalidate foo_m.w
-    invalidate foo_combmem.r
-    invalidate foo_combmem.w
+    invalidate foo_m
+    invalidate foo_combmem
 
   extmodule Foo_BlackBox:
     defname = Foo_BlackBox
@@ -58,10 +56,8 @@ circuit TestHarness:
       write-latency => 1
       read-under-write => undefined
 
-    invalidate bar_m.r
-    invalidate bar_m.w
-    invalidate bar_combmem.r
-    invalidate bar_combmem.w
+    invalidate bar_m
+    invalidate bar_combmem
 
   extmodule Bar_BlackBox:
     defname = Bar_BlackBox
@@ -87,10 +83,8 @@ circuit TestHarness:
       write-latency => 1
       read-under-write => undefined
 
-    invalidate baz_m.r
-    invalidate baz_m.w
-    invalidate baz_combmem.r
-    invalidate baz_combmem.w
+    invalidate baz_m
+    invalidate baz_combmem
 
   extmodule Baz_BlackBox:
     defname = Baz_BlackBox

test/Dialect/FIRRTL/parse-basic.fir

@@ -776,8 +776,7 @@ circuit MyModule :     ; CHECK: firrtl.circuit "MyModule" {
     ; CHECK: firrtl.matchingconnect %U0_in0, [[INV]]
     ; CHECK: [[INV:%.+]] = firrtl.invalidvalue : !firrtl.bundle<a: uint<5>>
     ; CHECK: firrtl.matchingconnect %U0_in1, [[INV]]
-    invalidate U0.in0
-    invalidate U0.in1
+    invalidate U0
 
   ; This reference is declared after its first use.
   ; https://github.com/llvm/circt/issues/163