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<p class="MsoNormal"><span style="font-size:11.0pt">Hi David,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Provided test case also calculates the maxstack correctly for me (with the recent codebase).<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Adam<span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="color:black">From:
</span></b><span style="color:black">classfile-api-dev <classfile-api-dev-retn@openjdk.org> on behalf of david32768@btinternet.com david32768@btinternet.com <david32768@btinternet.com><br>
<b>Date: </b>Wednesday, 30 October 2024 at 2:56<br>
<b>To: </b>classfile-api-dev@openjdk.org <classfile-api-dev@openjdk.org><br>
<b>Subject: </b>Re: Stack size miscalculated with try-catch blocks<o:p></o:p></span></p>
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<p>The problem is in StackMapGenerate.<o:p></o:p></p>
<p>The original method name of Frame.CheckStack is misleading as it adds 1 to index.<o:p></o:p></p>
<p>The recent changes assume it does not but there are still calls which assume this.<o:p></o:p></p>
<p> <o:p></o:p></p>
<p>testcode<br>
```<br>
import module java.base;<o:p></o:p></p>
<p>public class MaxStack {<o:p></o:p></p>
<p> private static void build(CodeBuilder cob) {<br>
cob<br>
.iload(0)<br>
.i2l()<br>
.lreturn();<br>
}<br>
<br>
public static void main(String[] args) throws IOException {<br>
ClassFile cf = v; // MaxStack = 3<br>
// ClassFile cf = v; // MaxStack = 2<br>
byte[] bytes = cf<br>
.build(ClassDesc.of("TestMaxStack"),<br>
clb -> clb.withFlags(ClassFile.ACC_PUBLIC | ClassFile.ACC_SUPER)<br>
.withVersion(49,0)<br>
.withMethodBody("Table", MethodTypeDesc.ofDescriptor("(I)J"),<br>
ClassFile.ACC_STATIC,<br>
MaxStack::build));<br>
cf = ClassFile.of();<br>
ClassModel cm = cf.parse(bytes);<br>
cm.methods().stream()<br>
.flatMap(m -> m.attributes().stream())<br>
.filter(attr -> attr instanceof CodeAttribute)<br>
.map(attr -> ((CodeAttribute)attr).maxStack())<br>
.map(sz -> "MaxStack = " + sz)<br>
.forEach(System.out::println);<br>
}<br>
}<br>
```<br>
<br>
<br>
<o:p></o:p></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p>------ Original Message ------<br>
From: rafael.wth@gmail.com<br>
To: classfile-api-dev@openjdk.org<br>
Sent: Thursday, October 24th 2024, 07:33<br>
Subject: Stack size miscalculated with try-catch blocks<br>
<o:p></o:p></p>
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<p class="MsoNormal">Hello,<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">when testing a recent build of the JDK with my bridge to ASM, I encountered some test failures. This is related to the stack size of a method being calculated with an additional, unnecessary slot. This can be reproduced using
<a href="https://github.com/raphw/asm-jdk-bridge" target="_blank">https://github.com/raphw/asm-jdk-bridge</a><o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">This can also be reproduced by inspecting the computed stack for:<o:p></o:p></p>
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<pre style="background:#1E1F22"><span style="color:#CF8E6D">void </span><span style="color:#56A8F5">c</span><span style="color:#BCBEC4">() {<br> </span><span style="color:#CF8E6D">try </span><span style="color:#BCBEC4">{<br> </span><span style="color:#CF8E6D">throw new </span><span style="color:#BCBEC4">RuntimeException();<br> } </span><span style="color:#CF8E6D">catch </span><span style="color:#BCBEC4">(RuntimeException e) {<br> }<br>}<o:p></o:p></span></pre>
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<p class="MsoNormal">which will be computed as 3 and not 2.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">Best regards, Rafael<br>
<o:p></o:p></p>
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