llvm-project [X86AsmParser] IntelExpression: End of Statement should check for valid end state

The following commit bfb7099eeb9b6f62510b1db0cb93a8c3cfa68236 added a special case for End of Statement that doesn't check if the state machine is rightfully in a state where ending is valid.

This PR suggest to revert this change to make EndOfStatement processed as any other tokens that are not consumable by the state machine.

Fixes https://github.com/llvm/llvm-project/issues/94446

Jun 15 '24 18:06 v01dXYZ

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Jun 15 '24 18:06 github-actions[bot]

@llvm/pr-subscribers-mc

@llvm/pr-subscribers-backend-x86

Author: None (v01dXYZ)

Changes

The following commit bfb7099eeb9b6f62510b1db0cb93a8c3cfa68236 added a special case for End of Statement that doesn't check if the state machine is rightfully in a state where ending is valid.

This PR suggest to revert this change to make EndOfStatement processed as any other tokens that are not consumable by the state machine.

Fixes https://github.com/llvm/llvm-project/issues/94446

Full diff: https://github.com/llvm/llvm-project/pull/95677.diff

1 Files Affected:

(modified) llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp (+2-4)

diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 6623106109316..d338607acbabe 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -473,7 +473,8 @@ class X86AsmParser : public MCTargetAsmParser {
     unsigned getLength() const { return CurType.Length; }
     int64_t getImm() { return Imm + IC.execute(); }
     bool isValidEndState() const {
-      return State == IES_RBRAC || State == IES_INTEGER;
+      return State == IES_RBRAC || State == IES_RPAREN ||
+             State == IES_INTEGER || State == IES_REGISTER;
     }
 
     // Is the intel expression appended after an operand index.
@@ -1897,9 +1898,6 @@ bool X86AsmParser::ParseIntelExpression(IntelExprStateMachine &SM, SMLoc &End) {
     case AsmToken::Error:
       return Error(getLexer().getErrLoc(), getLexer().getErr());
       break;
-    case AsmToken::EndOfStatement:
-      Done = true;
-      break;
     case AsmToken::Real:
       // DotOperator: [ebx].0
       UpdateLocLex = false;

Jun 18 '24 16:06 llvmbot

FYI, linux CI fails because of a (flaky ?) lldb test with a timeout.

Jun 23 '24 18:06 v01dXYZ

I repush the same commit to relaunch the CI. If you know a way to relaunch a failed CI pipeline, I want to know it too.

Jun 24 '24 09:06 v01dXYZ

Ping

Jul 01 '24 13:07 v01dXYZ

AsmParser is shared by assembler and fronr-end. Could you add a .s test to show what you fixed?

Jul 05 '24 06:07 KanRobert

Ping.

I added the case from the issue.

Jul 10 '24 18:07 v01dXYZ

I wonder if a customised AsmParser could potentially do it. Is it possible and worth it according to you ? There is certainly a reason why this machinery was not used at the time.

Jul 15 '24 08:07 v01dXYZ

I wonder if a customised AsmParser could potentially do it. Is it possible and worth it according to you ? There is certainly a reason why this machinery was not used at the time.

TBH, I am not clear about the history. This is a good wish of myself.

Jul 15 '24 08:07 KanRobert

FYI I don't have merge rights. if you consider the patch good enough, could you merge it on my behalf ?

I'll take a look at trying to replace some parts of the custom Expression Parser by the generic AsmParser at the beginning of next month as it is an interesting task about a very specific part of LLVM (thus perfect for a beginner like me). The code I'll write won't matter as much as the documentation about the suggestions.

Jul 15 '24 14:07 v01dXYZ

FYI I don't have merge rights. if you consider the patch good enough, could you merge it on my behalf ?

Sure.

Jul 16 '24 01:07 KanRobert

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Jul 16 '24 01:07 github-actions[bot]

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-4 while building llvm at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/1904

Here is the relevant piece of the build log for the reference:

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Analysis/StructuralHash/structural-hash-printer.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt -passes='print<structural-hash>' -disable-output /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll 2>&1 | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt '-passes=print<structural-hash>' -disable-output /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll
RUN: at line 2: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt -passes='print<structural-hash><detailed>' -disable-output /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll 2>&1 | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll -check-prefix=DETAILED-HASH
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt '-passes=print<structural-hash><detailed>' -disable-output /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll -check-prefix=DETAILED-HASH
[1m/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll:21:18: [0m[0;1;31merror: [0m[1mDETAILED-HASH: expected string not found in input
[0m; DETAILED-HASH: Module Hash: {{([a-z0-9]{14,})}}
[0;1;32m                 ^
[0m[1m<stdin>:1:1: [0m[0;1;30mnote: [0m[1mscanning from here
[0mModule Hash: 8d6dc22990ebe
[0;1;32m^
[0m
Input file: <stdin>
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Analysis/StructuralHash/structural-hash-printer.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
[1m[0m[0;1;30m          1: [0m[1m[0;1;46mModule Hash: 8d6dc22990ebe [0m
[0;1;31mcheck:21     X~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
[0m[0;1;30m          2: [0m[1m[0;1;46mFunction f1 Hash: 7062c67049c6f99c [0m
[0;1;31mcheck:21     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[0m[0;1;30m          3: [0m[1m[0;1;46mFunction f2 Hash: 1e47c72d08a2afcd [0m
[0;1;31mcheck:21     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[0m>>>>>>

--

********************

Jul 16 '24 01:07 llvm-ci