Print '(offset ...)` in data and element segments (#6379)

Previously we just printed the offset instruction(s) directly, which is a valid
shorthand only when there is a single instruction. In the case of extended
constant instructions, there can potentially be multiple instructions, in which
case the explicit `offset` clause is required. Print the full clause when
necessary.

2 files changed, 23 insertions, 2 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 3f0cfbabb..b0c83c437 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -21,6 +21,7 @@
 #include <ir/iteration.h>
 #include <ir/module-utils.h>
 #include <ir/table-utils.h>
+#include <ir/utils.h>
 #include <pass.h>
 #include <pretty_printing.h>
 #include <support/string.h>
@@ -3113,7 +3114,14 @@ void PrintSExpression::visitElementSegment(ElementSegment* curr) {
     }
 
     o << ' ';
+    bool needExplicitOffset = Measurer{}.measure(curr->offset) > 1;
+    if (needExplicitOffset) {
+      o << "(offset ";
+    }
     visit(curr->offset);
+    if (needExplicitOffset) {
+      o << ')';
+    }
 
     if (usesExpressions || currModule->tables.size() > 1) {
       o << ' ';
@@ -3183,7 +3191,14 @@ void PrintSExpression::visitDataSegment(DataSegment* curr) {
       curr->memory.print(o);
       o << ") ";
     }
+    bool needExplicitOffset = Measurer{}.measure(curr->offset) > 1;
+    if (needExplicitOffset) {
+      o << "(offset ";
+    }
     visit(curr->offset);
+    if (needExplicitOffset) {
+      o << ")";
+    }
     o << ' ';
   }
   String::printEscaped(o, {curr->data.data(), curr->data.size()});
diff --git a/test/lit/validation/extended-const.wast b/test/lit/validation/extended-const.wast
index 6b506671f..054c5e28e 100644
--- a/test/lit/validation/extended-const.wast
+++ b/test/lit/validation/extended-const.wast
@@ -11,14 +11,20 @@
 ;; EXTENDED:  (global.get $gimport$0)
 ;; EXTENDED:  (i32.const 42)
 ;; EXTENDED: ))
-;; EXTENDED: (data $0 (i32.sub
+;; EXTENDED: (data $0 (offset (i32.sub
 ;; EXTENDED:  (global.get $gimport$0)
 ;; EXTENDED:  (i32.const 10)
-;; EXTENDED: ) "hello world")
+;; EXTENDED: )) "hello world")
+;; EXTENDED: (elem $0 (offset (i32.sub
+;; EXTENDED:  (global.get $gimport$0)
+;; EXTENDED:  (i32.const 10)
+;; EXTENDED: )))
 
 (module
   (import "env" "global" (global i32))
   (memory 1 1)
+  (table 1 1 funcref)
   (global i32 (i32.add (global.get 0) (i32.const 42)))
   (data (offset (i32.sub (global.get 0) (i32.const 10))) "hello world")
+  (elem (offset (i32.sub (global.get 0) (i32.const 10))) func)
 )