[all-commits] [llvm/llvm-project] 8c5c2c: [clang][CodeGen] Exempt lifetime marker cleanups i...

[Nick Desaulniers via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8c5c2ccf47434b4c948e5b875c977bef4d15c84e
      https://github.com/llvm/llvm-project/commit/8c5c2ccf47434b4c948e5b875c977bef4d15c84e
  Author: Nick Desaulniers <ndesaulniers at google.com>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M clang/lib/CodeGen/CGCall.cpp
    M clang/lib/CodeGen/CGCleanup.cpp
    M clang/lib/CodeGen/CGCleanup.h
    M clang/lib/CodeGen/CGDecl.cpp
    M clang/lib/CodeGen/CodeGenFunction.h
    M clang/lib/CodeGen/EHScopeStack.h
    M clang/test/CodeGen/compound-literal-lifetime.c

  Log Message:
  -----------
  [clang][CodeGen] Exempt lifetime marker cleanups in musttail check (#224731)

PR #219045 started emitting @llvm.lifetime.start and @llvm.lifetime.end
markers for block-scoped compound literals in C via
pushCleanupAfterFullExpr<CallLifetimeEnd>.

When a compound literal is evaluated inside a conditional branch,
pushCleanupAfterFullExpr wraps CallLifetimeEnd inside
EHScopeStack::ConditionalCleanup, which did not override
EHScopeStack::Cleanup::isRedundantBeforeReturn(). Consequently,
CodeGenFunction::EmitCall rejected [[clang::musttail]] calls when a
conditional compound literal was in scope at -O1 and above.

Because EHScopeStack::ConditionalCleanup wraps cleanups by composition,
virtual methods on EHScopeStack::Cleanup other than Emit() do not work
for conditional cleanups. Replace the virtual
EHScopeStack::Cleanup::isRedundantBeforeReturn() method with a
StackRestore bit on CleanupKind/EHCleanupScope alongside the existing
LifetimeMarker bit, and check EHCleanupScope::isRedundantBeforeReturn()
in CodeGenFunction::EmitCall.

Assisted-by: Gemini
Fixes: 93b2629d1d1f ("[clang][CodeGen] Emit lifetime markers for
block-scoped compound literals in C (#219045)")
Fixes: https://github.com/llvm/llvm-project/issues/224337



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