escape asm consts

2 files changed, 24 insertions, 2 deletions

diff --git a/src/s2wasm.h b/src/s2wasm.h
index bdeb78fdd..5fccef19b 100644
--- a/src/s2wasm.h
+++ b/src/s2wasm.h
@@ -880,11 +880,33 @@ public:
         if (curr->target == EMSCRIPTEN_ASM_CONST) {
           auto arg = curr->operands[0]->cast<Const>();
           size_t segmentIndex = parent->addressSegments[arg->value.geti32()];
-          std::string code = parent->wasm.memory.segments[segmentIndex].data;
+          std::string code = escape(parent->wasm.memory.segments[segmentIndex].data);
           std::string sig = getSig(curr);
           sigsForCode[code].insert(sig);
         }
       }
+
+      std::string escape(const char *input) {
+        std::string code = input;
+        // replace newlines quotes with escaped newlines
+        size_t curr = 0;
+        while ((curr = code.find("\\n", curr)) != std::string::npos) {
+          code = code.replace(curr, 2, "\\\\n");
+          curr += 3; // skip this one
+        }
+        // replace double quotes with escaped single quotes
+        curr = 0;
+        while ((curr = code.find('"', curr)) != std::string::npos) {
+          if (curr == 0 || code[curr-1] != '\\') {
+            code = code.replace(curr, 1, "\\" "\"");
+            curr += 2; // skip this one
+          } else { // already escaped, escape the slash as well
+            code = code.replace(curr, 1, "\\" "\\" "\"");
+            curr += 3; // skip this one
+          }
+        }
+        return code;
+      }
     };
     AsmConstWalker walker(this);
     walker.startWalk(&wasm);
diff --git a/test/dot_s/asm_const.wast b/test/dot_s/asm_const.wast
index 695c480b3..37ff45061 100644
--- a/test/dot_s/asm_const.wast
+++ b/test/dot_s/asm_const.wast
@@ -15,4 +15,4 @@
     )
   )
 )
-; METADATA: { "asmConsts": {"{ Module.print("hello, world!"); }":["vi"]} }
\ No newline at end of file
+; METADATA: { "asmConsts": {"{ Module.print(\"hello, world!\"); }":["vi"]} }
\ No newline at end of file