[Strings] string.is_usv_sequence (WebAssembly#4783)

kripken · web-flow · commit fea11e95c67d · 2022-07-08T13:37:50.000-07:00
This implements it as a StringMeasure opcode. They do have the same number of
operands, same trapping behavior, and same return type. They both get a string and
do some inspection of it to return an i32. Perhaps the name could be StringInspect
or something like that, rather than StringMeasure..? But I think for now this might be
good enough, and the spec may change anyhow later.
diff --git a/scripts/gen-s-parser.py b/scripts/gen-s-parser.py
@@ -619,6 +619,7 @@
     ("string.const",         "makeStringConst(s)"),
     ("string.measure_wtf8",  "makeStringMeasure(s, StringMeasureWTF8)"),
     ("string.measure_wtf16", "makeStringMeasure(s, StringMeasureWTF16)"),
+    ("string.is_usv_sequence", "makeStringMeasure(s, StringMeasureIsUSV)"),
     ("string.encode_wtf8",   "makeStringEncode(s, StringEncodeWTF8)"),
     ("string.encode_wtf16",  "makeStringEncode(s, StringEncodeWTF16)"),
     ("string.concat",        "makeStringConcat(s)"),
diff --git a/src/gen-s-parser.inc b/src/gen-s-parser.inc
@@ -3159,6 +3159,9 @@ switch (op[0]) {
                   default: goto parse_error;
                 }
               }
+              case 'i':
+                if (strcmp(op, "string.is_usv_sequence") == 0) { return makeStringMeasure(s, StringMeasureIsUSV); }
+                goto parse_error;
               case 'm': {
                 switch (op[18]) {
                   case '1':
diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
@@ -2253,6 +2253,9 @@ struct PrintExpressionContents
       case StringMeasureWTF16:
         printMedium(o, "string.measure_wtf16");
         break;
+      case StringMeasureIsUSV:
+        printMedium(o, "string.is_usv_sequence");
+        break;
       default:
         WASM_UNREACHABLE("invalid string.measure*");
     }
diff --git a/src/wasm-binary.h b/src/wasm-binary.h
@@ -1146,6 +1146,7 @@ enum ASTNodes {
   StringEncodeWTF16 = 0x87,
   StringConcat = 0x88,
   StringEq = 0x89,
+  StringIsUSV = 0x8a,
 };
 
 enum MemoryAccess {
diff --git a/src/wasm.h b/src/wasm.h
@@ -594,6 +594,7 @@ enum StringMeasureOp {
   StringMeasureUTF8,
   StringMeasureWTF8,
   StringMeasureWTF16,
+  StringMeasureIsUSV,
 };
 
 enum StringEncodeOp {
diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
@@ -7191,6 +7191,8 @@ bool WasmBinaryBuilder::maybeVisitStringMeasure(Expression*& out,
     }
   } else if (code == BinaryConsts::StringMeasureWTF16) {
     op = StringMeasureWTF16;
+  } else if (code == BinaryConsts::StringIsUSV) {
+    op = StringMeasureIsUSV;
   } else {
     return false;
   }
diff --git a/src/wasm/wasm-stack.cpp b/src/wasm/wasm-stack.cpp
@@ -2276,6 +2276,9 @@ void BinaryInstWriter::visitStringMeasure(StringMeasure* curr) {
     case StringMeasureWTF16:
       o << U32LEB(BinaryConsts::StringMeasureWTF16);
       break;
+    case StringMeasureIsUSV:
+      o << U32LEB(BinaryConsts::StringIsUSV);
+      break;
     default:
       WASM_UNREACHABLE("invalid string.new*");
   }
diff --git a/test/lit/strings.wast b/test/lit/strings.wast
@@ -225,4 +225,23 @@
       )
     )
   )
+
+  ;; CHECK:      (func $string.is_usv_sequence (param $ref stringref)
+  ;; CHECK-NEXT:  (drop
+  ;; CHECK-NEXT:   (i32.eqz
+  ;; CHECK-NEXT:    (string.is_usv_sequence
+  ;; CHECK-NEXT:     (local.get $ref)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $string.is_usv_sequence (param $ref stringref)
+    (drop
+      (i32.eqz ;; validate the output is i32
+        (string.is_usv_sequence
+          (local.get $ref)
+        )
+      )
+    )
+  )
 )

Original file line number	Diff line number	Diff line change
`@@ -3159,6 +3159,9 @@ switch (op[0]) {`
`3159`	`3159`	`default: goto parse_error;`
`3160`	`3160`	`}`
`3161`	`3161`	`}`
	`3162`	`+ case 'i':`
	`3163`	`+ if (strcmp(op, "string.is_usv_sequence") == 0) { return makeStringMeasure(s, StringMeasureIsUSV); }`
	`3164`	`+ goto parse_error;`
`3162`	`3165`	`case 'm': {`
`3163`	`3166`	`switch (op[18]) {`
`3164`	`3167`	`case '1':`
Original file line number	Diff line number	Diff line change
`@@ -7191,6 +7191,8 @@ bool WasmBinaryBuilder::maybeVisitStringMeasure(Expression*& out,`
`7191`	`7191`	`}`
`7192`	`7192`	`} else if (code == BinaryConsts::StringMeasureWTF16) {`
`7193`	`7193`	`op = StringMeasureWTF16;`
	`7194`	`+ } else if (code == BinaryConsts::StringIsUSV) {`
	`7195`	`+ op = StringMeasureIsUSV;`
`7194`	`7196`	`} else {`
`7195`	`7197`	`return false;`
`7196`	`7198`	`}`
Original file line number	Diff line number	Diff line change
`@@ -225,4 +225,23 @@`
`225`	`225`	`)`
`226`	`226`	`)`
`227`	`227`	`)`
	`228`	`+`
	`229`	`+ ;; CHECK: (func $string.is_usv_sequence (param $ref stringref)`
	`230`	`+ ;; CHECK-NEXT: (drop`
	`231`	`+ ;; CHECK-NEXT: (i32.eqz`
	`232`	`+ ;; CHECK-NEXT: (string.is_usv_sequence`
	`233`	`+ ;; CHECK-NEXT: (local.get $ref)`
	`234`	`+ ;; CHECK-NEXT: )`
	`235`	`+ ;; CHECK-NEXT: )`
	`236`	`+ ;; CHECK-NEXT: )`
	`237`	`+ ;; CHECK-NEXT: )`
	`238`	`+ (func $string.is_usv_sequence (param $ref stringref)`
	`239`	`+ (drop`
	`240`	`+ (i32.eqz ;; validate the output is i32`
	`241`	`+ (string.is_usv_sequence`
	`242`	`+ (local.get $ref)`
	`243`	`+ )`
	`244`	`+ )`
	`245`	`+ )`
	`246`	`+ )`
`228`	`247`	`)`