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[BOLT] Always treat function entry as code #160161

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Merged
merged 1 commit into from
Oct 6, 2025
Merged

[BOLT] Always treat function entry as code #160161

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13 changes: 8 additions & 5 deletions bolt/lib/Rewrite/RewriteInstance.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -917,9 +917,6 @@ void RewriteInstance::discoverFileObjects() {
bool IsData = false;
uint64_t LastAddr = 0;
for (const auto &SymInfo : SortedSymbols) {
if (LastAddr == SymInfo.Address) // don't repeat markers
continue;

MarkerSymType MarkerType = BC->getMarkerType(SymInfo.Symbol);

// Treat ST_Function as code.
Expand All @@ -929,8 +926,14 @@ void RewriteInstance::discoverFileObjects() {
if (IsData) {
Expected<StringRef> NameOrError = SymInfo.Symbol.getName();
consumeError(NameOrError.takeError());
BC->errs() << "BOLT-WARNING: function symbol " << *NameOrError
<< " lacks code marker\n";
if (LastAddr == SymInfo.Address) {
BC->errs() << "BOLT-WARNING: ignoring data marker conflicting with "
"function symbol "
<< *NameOrError << '\n';
} else {
BC->errs() << "BOLT-WARNING: function symbol " << *NameOrError
<< " lacks code marker\n";
}
}
MarkerType = MarkerSymType::CODE;
}
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17 changes: 0 additions & 17 deletions bolt/test/AArch64/data-at-0-offset.c
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23 changes: 23 additions & 0 deletions bolt/test/AArch64/function-data-marker.s
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Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
## Check that if a data marker is present at the start of a function, the
## underlying bytes are still treated as code.

# RUN: %clang %cflags %s -o %t.exe
# RUN: llvm-bolt %t.exe -o %t.bolt --print-cfg 2>&1 | FileCheck %s

# CHECK: BOLT-WARNING: ignoring data marker conflicting with function symbol _start

.text
.balign 4

## Data marker is emitted because ".long" directive is used instead of ".inst".
.global _start
.type _start, %function
_start:
.long 0xcec08000 // sha512su0 v0.2d, v0.2d
ret
.size _start, .-_start

# CHECK-LABEL: Binary Function "_start"
# CHECK: Entry Point
# CHECK-NEXT: sha512su0 v0.2d, v0.2d

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