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Fix: remove excess optimization for sourcemap #5547

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Fix: remove excess optimization for sourcemap #5547

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16 changes: 14 additions & 2 deletions src/passes/Print.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
// Print out text in s-expression format
//

#include <cstdint>
#include <ir/iteration.h>
#include <ir/module-utils.h>
#include <ir/table-utils.h>
Expand Down Expand Up @@ -2532,7 +2533,7 @@ struct PrintExpressionContents
// internal contents and the nested children.
struct PrintSExpression : public UnifiedExpressionVisitor<PrintSExpression> {
std::ostream& o;
unsigned indent = 0;
uint32_t indent = 0U;

bool minify;
const char* maybeSpace;
Expand All @@ -2547,6 +2548,10 @@ struct PrintSExpression : public UnifiedExpressionVisitor<PrintSExpression> {
Module* currModule = nullptr;
Function* currFunction = nullptr;
Function::DebugLocation lastPrintedLocation;
uint32_t lastPrintedIndent =
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@JesseCodeBones JesseCodeBones Aug 2, 2023 •
edited
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we will cache last print indent as the depth of last printed instruction
@kripken

static_cast<uint32_t>(-1); ///< last print indent, child will not duplicate
///< the debug location, siblings will not miss
///< the debug location
bool debugInfo;

// Used to print delegate's depth argument when it throws to the caller
Expand All @@ -2560,10 +2565,17 @@ struct PrintSExpression : public UnifiedExpressionVisitor<PrintSExpression> {
}

void printDebugLocation(const Function::DebugLocation& location) {
if (lastPrintedLocation == location) {
// ;; debug location
// (parent
// (child) ;; no debug location
// )
// ;; debug location
// (siblings)
if (lastPrintedLocation == location && indent > lastPrintedIndent) {
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@kripken
Hi Alon,
the easiest way to check the debug info is remove this filter for debugging, here is my step:
1, remove this condition return
2, build binaryen
3, run cmd: ./build/bin/wasm-opt ./test/fib-dbg.wasm -ism ./test/fib-dbg.wasm.map --print
then wasm-opt will print all debug info.
so you can check if the new added annotation of debug info is reasonable or not.
if any other question, please feel free to ask, thank you.

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@kripken
Hi Alon,
here is the wat file(fib-dbg.wasm.fromBinary) will full debug info printed:

(module
 (type $i32_=>_i32 (func (param i32) (result i32)))
 (type $i32_i32_=>_none (func (param i32 i32)))
 (type $none_=>_i32 (func (result i32)))
 (type $i32_=>_none (func (param i32)))
 (type $none_=>_none (func))
 (import "env" "memory" (memory $mimport$0 256 256))
 (import "env" "table" (table $timport$0 0 0 funcref))
 (import "env" "DYNAMICTOP_PTR" (global $gimport$0 i32))
 (import "env" "tempDoublePtr" (global $gimport$1 i32))
 (import "env" "ABORT" (global $gimport$2 i32))
 (import "env" "STACKTOP" (global $gimport$3 i32))
 (import "env" "STACK_MAX" (global $gimport$4 i32))
 (import "env" "gb" (global $gimport$5 i32))
 (import "env" "fb" (global $gimport$6 i32))
 (import "global" "NaN" (global $gimport$7 f64))
 (import "global" "Infinity" (global $gimport$8 f64))
 (import "env" "memoryBase" (global $gimport$9 i32))
 (import "env" "tableBase" (global $gimport$10 i32))
 (global $global$0 (mut i32) (global.get $gimport$0))
 (global $global$1 (mut i32) (global.get $gimport$1))
 (global $global$2 (mut i32) (global.get $gimport$2))
 (global $global$3 (mut i32) (global.get $gimport$3))
 (global $global$4 (mut i32) (global.get $gimport$4))
 (global $global$5 (mut i32) (global.get $gimport$5))
 (global $global$6 (mut i32) (global.get $gimport$6))
 (global $global$7 (mut i32) (i32.const 0))
 (global $global$8 (mut i32) (i32.const 0))
 (global $global$9 (mut i32) (i32.const 0))
 (global $global$10 (mut i32) (i32.const 0))
 (global $global$11 (mut f64) (global.get $gimport$7))
 (global $global$12 (mut f64) (global.get $gimport$8))
 (global $global$13 (mut i32) (i32.const 0))
 (global $global$14 (mut i32) (i32.const 0))
 (global $global$15 (mut i32) (i32.const 0))
 (global $global$16 (mut i32) (i32.const 0))
 (global $global$17 (mut f64) (f64.const 0))
 (global $global$18 (mut i32) (i32.const 0))
 (global $global$19 (mut i32) (i32.const 0))
 (global $global$20 (mut i32) (i32.const 0))
 (global $global$21 (mut f64) (f64.const 0))
 (global $global$22 (mut i32) (i32.const 0))
 (global $global$23 (mut f64) (f64.const 0))
 (export "setThrew" (func $setThrew))
 (export "runPostSets" (func $runPostSets))
 (export "establishStackSpace" (func $establishStackSpace))
 (export "stackSave" (func $stackSave))
 (export "stackRestore" (func $stackRestore))
 (export "_fib" (func $_fib))
 (export "stackAlloc" (func $stackAlloc))
 (func $stackAlloc (param $0 i32) (result i32)
  (local $1 i32)
  (block $label$1
   (local.set $1
    (global.get $global$3)
   )
   (global.set $global$3
    (i32.add
     (global.get $global$3)
     (local.get $0)
    )
   )
   (global.set $global$3
    (i32.and
     (i32.add
      (global.get $global$3)
      (i32.const 15)
     )
     (i32.const -16)
    )
   )
   (return
    (local.get $1)
   )
  )
 )
 (func $stackSave (result i32)
  (return
   (global.get $global$3)
  )
 )
 (func $stackRestore (param $0 i32)
  (global.set $global$3
   (local.get $0)
  )
 )
 (func $establishStackSpace (param $0 i32) (param $1 i32)
  (block $label$1
   (global.set $global$3
    (local.get $0)
   )
   (global.set $global$4
    (local.get $1)
   )
  )
 )
 (func $setThrew (param $0 i32) (param $1 i32)
  (if
   (i32.eq
    (global.get $global$7)
    (i32.const 0)
   )
   (block
    (global.set $global$7
     (local.get $0)
    )
    (global.set $global$8
     (local.get $1)
    )
   )
  )
 )
 (func $_fib (param $0 i32) (result i32)
  (local $1 i32)
  (local $2 i32)
  (local $3 i32)
  (local $4 i32)
  (local $5 i32)
  (local $6 i32)
  (local $7 i32)
  (local $8 i32)
  (local $9 i32)
  (local $10 i32)
  (local $11 i32)
  (block $label$1
   (local.set $11
    (global.get $global$3)
   )
   ;;@ fib.c:3:0
   (local.set $6
    ;;@ fib.c:3:0
    (i32.gt_s
     ;;@ fib.c:3:0
     (local.get $0)
     ;;@ fib.c:3:0
     (i32.const 0)
    )
   )
   ;;@ fib.c:3:0
   (if
    ;;@ fib.c:3:0
    (local.get $6)
    (block
     ;;@ fib.c:3:0
     (local.set $1
      ;;@ fib.c:3:0
      (i32.const 0)
     )
     ;;@ fib.c:3:0
     (local.set $5
      ;;@ fib.c:3:0
      (i32.const 1)
     )
     ;;@ fib.c:3:0
     (local.set $8
      ;;@ fib.c:3:0
      (i32.const 0)
     )
    )
    (block
     ;;@ fib.c:3:0
     (local.set $4
      ;;@ fib.c:3:0
      (i32.const 1)
     )
     ;;@ fib.c:8:0
     (return
      ;;@ fib.c:8:0
      (local.get $4)
     )
    )
   )
   ;;@ fib.c:8:0
   (loop $label$4
    ;;@ fib.c:8:0
    (block $label$5
     ;;@ fib.c:4:0
     (local.set $3
      ;;@ fib.c:4:0
      (i32.add
       ;;@ fib.c:4:0
       (local.get $5)
       ;;@ fib.c:4:0
       (local.get $1)
      )
     )
     ;;@ fib.c:3:0
     (local.set $9
      ;;@ fib.c:3:0
      (i32.add
       ;;@ fib.c:3:0
       (local.get $8)
       ;;@ fib.c:3:0
       (i32.const 1)
      )
     )
     ;;@ fib.c:3:0
     (local.set $7
      ;;@ fib.c:3:0
      (i32.eq
       ;;@ fib.c:3:0
       (local.get $9)
       ;;@ fib.c:3:0
       (local.get $0)
      )
     )
     ;;@ fib.c:3:0
     (if
      ;;@ fib.c:3:0
      (local.get $7)
      (block
       ;;@ fib.c:3:0
       (local.set $4
        ;;@ fib.c:3:0
        (local.get $3)
       )
       ;;@ fib.c:3:0
       (br $label$5)
      )
      (block
       ;;@ fib.c:3:0
       (local.set $2
        ;;@ fib.c:3:0
        (local.get $5)
       )
       ;;@ fib.c:3:0
       (local.set $5
        ;;@ fib.c:3:0
        (local.get $3)
       )
       ;;@ fib.c:3:0
       (local.set $8
        ;;@ fib.c:3:0
        (local.get $9)
       )
       ;;@ fib.c:3:0
       (local.set $1
        ;;@ fib.c:3:0
        (local.get $2)
       )
      )
     )
     ;;@ fib.c:3:0
     (br $label$4)
    )
   )
   (return
    ;;@ fib.c:8:0
    (local.get $4)
   )
  )
 )
 (func $runPostSets
  (local $0 i32)
  (nop)
 )
 ;; custom section "sourceMappingURL", size 35, contents: "\"http://localhost:8000/fib.wasm.map"
)

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I see, thanks, and sorry for the delay.

I'll look at this again soon, but first, I have recently been debugging another source maps issue (a user reported the wrong annotation somewhere), and so I read the source maps spec again and then our code. I have to say I am still a little confused on it. It seems like the spec says nothing about ranges or how to infer debug locations for things without an annotation, but Binaryen does do that - it will keep using a debug location after it sees one, until the next. I am not sure if that is correct or not, and I'm not sure if that is related to this PR or not, but the binary format parts seem like they might be? I am quite worried about changing it, because of how it might affect other users...

For this PR specifically, since I would like to move forward on it: Is it possible to split the Print parts from the binary format parts? I think there is a low bar to landing a Print improvement, but a high bar for a binary format change (again, because users could be affected by the latter). So if we can split it, that would make review simpler, and also allow the Print part to land quickly I hope.

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@kripken
yep, I will splite the PR and suppose the print PR will comming soon

return;
}
lastPrintedLocation = location;
lastPrintedIndent = indent;
auto fileName = currModule->debugInfoFileNames[location.fileIndex];
o << ";;@ " << fileName << ":" << location.lineNumber << ":"
<< location.columnNumber << '\n';
Expand Down
2 changes: 0 additions & 2 deletions src/wasm-binary.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1343,7 +1343,6 @@ class WasmBinaryWriter {
void writeDylinkSection();
void writeLegacyDylinkSection();

void initializeDebugInfo();
void writeSourceMapProlog();
void writeSourceMapEpilog();
void writeDebugLocation(const Function::DebugLocation& loc);
Expand Down Expand Up @@ -1404,7 +1403,6 @@ class WasmBinaryWriter {
std::vector<std::pair<size_t, const Function::DebugLocation*>>
sourceMapLocations;
size_t sourceMapLocationsSizeAtSectionStart;
Function::DebugLocation lastDebugLocation;

std::unique_ptr<ImportInfo> importInfo;

Expand Down
28 changes: 26 additions & 2 deletions src/wasm-stack.h
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Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@
#include "wasm-binary.h"
#include "wasm-traversal.h"
#include "wasm.h"
#include <cstdint>

namespace wasm {

Expand Down Expand Up @@ -154,7 +155,10 @@ class BinaryInstWriter : public OverriddenVisitor<BinaryInstWriter> {
template<typename SubType>
class BinaryenIRWriter : public Visitor<BinaryenIRWriter<SubType>> {
public:
BinaryenIRWriter(Function* func) : func(func) {}
BinaryenIRWriter(Function* func)
: func(func), lastDebugLocation({static_cast<uint32_t>(-1),
static_cast<uint32_t>(-1),
static_cast<uint32_t>(-1)}) {}

void write();

Expand All @@ -168,6 +172,10 @@ class BinaryenIRWriter : public Visitor<BinaryenIRWriter<SubType>> {

protected:
Function* func = nullptr;
Function::DebugLocation lastDebugLocation; ///< last debug location
uint32_t lastDebugLocationDepth =
static_cast<uint32_t>(-1); ///< last debug location depth
uint32_t depth = 0U; ///< depth of current write cursor

private:
void emit(Expression* curr) { static_cast<SubType*>(this)->emit(curr); }
Expand Down Expand Up @@ -239,6 +247,7 @@ void BinaryenIRWriter<SubType>::visit(Expression* curr) {
// unreachable block is a source of unreachability, which means we don't need
// to emit an extra `unreachable` before the end of the block to prevent type
// errors.
depth++;
bool hasUnreachableChild = false;
for (auto* child : ValueChildIterator(curr)) {
visit(child);
Expand All @@ -251,7 +260,22 @@ void BinaryenIRWriter<SubType>::visit(Expression* curr) {
// `curr` is not reachable, so don't emit it.
return;
}
emitDebugLocation(curr);

if (func != nullptr) {
const auto& debugLocationIterator = func->debugLocations.find(curr);
if (debugLocationIterator != func->debugLocations.cend()) {
if (lastDebugLocation != debugLocationIterator->second ||
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for the function debug info emit, we add the depth logic, if the parent or siblings instruction already inserted the debuginfo, the instruction will not emit the debug info in source map generation, it will not impact the debug info reload from source map (children and siblings instructions will also get the debug info when load them from source map to memory structures), just optimize the generation of source map.
@kripken

depth < lastDebugLocationDepth) {
emitDebugLocation(curr);
lastDebugLocationDepth = depth;
lastDebugLocation = debugLocationIterator->second;
}
}
} else {
emitDebugLocation(
curr); // for global expression write, no func value, directly write it
}
depth--;
// Control flow requires special handling, but most instructions can be
// emitted directly after their children.
if (Properties::isControlFlowStructure(curr)) {
Expand Down
9 changes: 0 additions & 9 deletions src/wasm/wasm-binary.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -43,7 +43,6 @@ void WasmBinaryWriter::write() {

writeDylinkSection();

initializeDebugInfo();
if (sourceMap) {
writeSourceMapProlog();
}
Expand Down Expand Up @@ -1120,10 +1119,6 @@ void WasmBinaryWriter::writeSymbolMap() {
file.close();
}

void WasmBinaryWriter::initializeDebugInfo() {
lastDebugLocation = {0, /* lineNumber = */ 1, 0};
}

void WasmBinaryWriter::writeSourceMapProlog() {
*sourceMap << "{\"version\":3,\"sources\":[";
for (size_t i = 0; i < wasm->debugInfoFileNames.size(); i++) {
Expand Down Expand Up @@ -1304,12 +1299,8 @@ void WasmBinaryWriter::writeDylinkSection() {
}

void WasmBinaryWriter::writeDebugLocation(const Function::DebugLocation& loc) {
if (loc == lastDebugLocation) {
return;
}
auto offset = o.size();
sourceMapLocations.emplace_back(offset, &loc);
lastDebugLocation = loc;
}

void WasmBinaryWriter::writeDebugLocation(Expression* curr, Function* func) {
Expand Down
5 changes: 5 additions & 0 deletions test/fib-dbg.wasm.fromBinary
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Original file line number Diff line number Diff line change
Expand Up @@ -133,6 +133,7 @@
(i32.const 0)
)
)
;;@ fib.c:3:0
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I'm trying to understand why this addition is correct. So I turned the sourcemap to json, and there are three entries for line 3:

  {
    "generatedLine": 1,
    "generatedColumn": 643,
    "lastGeneratedColumn": null,
    "source": "fib.c",
    "originalLine": 3,
    "originalColumn": 0,
    "name": null
  },
  {
    "generatedLine": 1,
    "generatedColumn": 686,
    "lastGeneratedColumn": null,
    "source": "fib.c",
    "originalLine": 3,
    "originalColumn": 0,
    "name": null
  },
  {
    "generatedLine": 1,
    "generatedColumn": 693,
    "lastGeneratedColumn": null,
    "source": "fib.c",
    "originalLine": 3,
    "originalColumn": 0,
    "name": null
  },

Before this PR there are two locations where line 3 is mentioned in the .fromBinary file here. So I'd expect one more to appear, to get to 3 appearances to match the source map. But this PR adds more than that. Am I looking at this wrong?

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@kripken Hi Alon,
sourceMap location is not one by one equal to the debug location of expression. it is a range concept.
to be short, if expression offset is between previous source map debug location offset and current source map debug location offset, this expression will take the previous source map debug location.
before this change, the debug location of siblings element just were not printed, but it existed in the functionRef->debugLocations, so this change just print it and it is more clear to see which instruction is under which location.

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if remove the filter condition of printDebugLocation of Print.cpp.
it will print all locations to all expressions, and it is more clear to see the location information, and just for debug, print all debug location is not neccessary I suppose.

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Is the range concept idea documented somewhere? I'm not familiar with that. I had assumed source maps are just individual locations, but I could be wrong...

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Hi Alon,
I didnot find the documentation of the solution, this may come from PR:
#1017
Here is the read and write flow:

  1. wasm-opt read:
    wasm-s-parser.h function: SExpressionParser::parseDebugLocation it will update loc of SExpressionParser, so the after expression will take this position until the loc will updated with another debug location.
  2. binary write:
    WasmBinaryWriter::writeSourceMapEpilog
writeBase64VLQ(*sourceMap, int32_t(offset - lastOffset));
writeBase64VLQ(*sourceMap, int32_t(loc->fileIndex - lastLoc.fileIndex));
writeBase64VLQ(*sourceMap, int32_t(loc->lineNumber - lastLoc.lineNumber));
writeBase64VLQ(*sourceMap,
                 int32_t(loc->columnNumber - lastLoc.columnNumber));

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@kripken
Hi Alon,
I suppose the primary design for source map is shrink the size of debug info like DWARF, but source map is lack the control instructions, so do you think we should back to point to point solution for source map debug info?

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Hi @JesseCodeBones , sorry for the late response. I don't know that much about this and was hoping someone else would know...

I think you might be right, that there are ranges here, since we keep using the same value until it is updated. I was not aware of that before. But since that is how it is, we shouldn't change it, I guess.

To move forward here, getting back to the start of this thread, I think it would be helpful to explain the diffs in this PR. That is, I'm still not sure how to read the diff here and check that it is correct. Something like "this annotation appeared here because of this part of the sourcemap" would be good.

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@kripken
Hi Alon,
the changes contains two parts:
part 1: during printing, if parent ancestors node already printed the debug info, skip print
part 2: during source map generation, only ancestors generate the source map debug info
I am not sure if it is clear, if you have any question, please feel free to ask me

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I think I understand that, and the code sort of makes sense. But I am having specific trouble in reading the diffs in the testcase specifically. That is where I need help. I'll add a comment on a specific part of the test diff now.

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Oh, sorry, this is already on a test diff 😄 Then, yeah: how can I see that this addition on line 136 is a correct one to add? I'm not sure how to read the sourcemap itself and see that it says there should be an annotation here.

(if
(local.get $6)
(block
Expand All @@ -156,6 +157,7 @@
)
)
)
;;@ fib.c:8:0
(loop $label$4
(block $label$5
;;@ fib.c:4:0
Expand All @@ -172,12 +174,14 @@
(i32.const 1)
)
)
;;@ fib.c:3:0
(local.set $7
(i32.eq
(local.get $9)
(local.get $0)
)
)
;;@ fib.c:3:0
(if
(local.get $7)
(block
Expand All @@ -201,6 +205,7 @@
)
)
)
;;@ fib.c:3:0
(br $label$4)
)
)
Expand Down
81 changes: 81 additions & 0 deletions test/lit/source-map-siblings-print.wast
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Original file line number Diff line number Diff line change
@@ -0,0 +1,81 @@
;; RUN: wasm-opt %s -o %t.wasm -osm %t.map -g -q
;; RUN: wasm-opt %t.wasm -ism %t.map -q -o - -S | filecheck %s

(module
(func $foo (param $x i32) (param $y i32)
;;@ src.cpp:1:1
(if
(i32.add
(local.get $x)
;;@ src.cpp:2:1
(local.get $y)
)
;;@ src.cpp:3:1
(return)
)
;;@ src.cpp:1:1
(block
;;@ src.cpp:4:1
(drop
(i32.add
(local.get $x)
;;@ src.cpp:5:1
(local.get $y)
)
)
(drop
(i32.sub
(local.get $x)
(local.get $y)
)
)
)
(drop
(i32.mul
(local.get $x)
;;@ src.cpp:6:1
(local.get $y)
)
)
(return)
)
)

;; CHECK: (func $foo (param $x i32) (param $y i32)
;; CHECK-NEXT: ;;@ src.cpp:1:1
;; CHECK-NEXT: (if
;; CHECK-NEXT: (i32.add
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: ;;@ src.cpp:2:1
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: )
;; CHECK-NEXT: ;;@ src.cpp:3:1
;; CHECK-NEXT: (return)
;; CHECK-NEXT: )
;; CHECK-NEXT: ;;@ src.cpp:4:1
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.add
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: ;;@ src.cpp:5:1
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: ;;@ src.cpp:4:1
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.sub
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: ;;@ src.cpp:1:1
;; CHECK-NEXT: (drop
;; CHECK-NEXT: (i32.mul
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: ;;@ src.cpp:6:1
;; CHECK-NEXT: (local.get $y)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: ;;@ src.cpp:1:1
;; CHECK-NEXT: (return)
;; CHECK-NEXT: )
;; CHECK-NEXT:)