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[BoundsSafety] Re-introduce -funique-traps as a legacy alias of -fbounds-safety-unique-traps #11602

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Merged
merged 1 commit into from
Oct 9, 2025
Merged

[BoundsSafety] Re-introduce -funique-traps as a legacy alias of -fbounds-safety-unique-traps #11602

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16 changes: 14 additions & 2 deletions clang/include/clang/Driver/Options.td
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Original file line number Diff line number Diff line change
Expand Up @@ -2039,14 +2039,26 @@ def fno_bounds_safety_bringup_missing_checks : Flag<["-"], "fno-bounds-safety-br

defm bounds_safety_unique_traps : BoolFOption<"bounds-safety-unique-traps",
CodeGenOpts<"BoundsSafetyUniqueTraps">, DefaultFalse,
PosFlag<SetTrue, [], [CC1Option],
PosFlag<SetTrue, [], [ClangOption, CC1Option],
"Make trap instructions unique by preventing traps from being merged by the"
" optimizer. This is useful for preserving the debug information on traps "
"in optimized code. This makes it easier to debug programs at the cost of "
"increased code size">,
NegFlag<SetFalse, [], [CC1Option],
NegFlag<SetFalse, [], [ClangOption, CC1Option],
"Don't try to make trap instructions unique. This allows trap instructions "
"to be merged by the optimizer.">>;

// Legacy aliases
// TODO(dliew): Remove these (rdar://162215869).
// This isn't declared using `Alias<fbounds_safety_unique_traps>` because that
// prevents identifying that this flag as distinct from
// `fbounds_safety_unique_traps`.
defm bounds_safety_legacy_unique_traps : BoolOptionWithoutMarshalling<"f", "unique-traps",
PosFlag<SetTrue, [], [ClangOption],
"legacy alias for -fbounds-safety-unique-traps">,
NegFlag<SetFalse, [], [ClangOption],
"legacy alias for -fno-bounds-safety-unique-traps">>;

// TO_UPSTREAM(BoundsSafety) OFF

defm lifetime_safety : BoolFOption<
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39 changes: 37 additions & 2 deletions clang/lib/Driver/ToolChains/Clang.cpp
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Expand Up @@ -7039,8 +7039,43 @@ void Clang::ConstructJob(Compilation &C, const JobAction &Job,
<< "-ftrap-function-returns" << "-ftrap-function=";
}

Args.addOptInFlag(CmdArgs, options::OPT_fbounds_safety_unique_traps,
options::OPT_fno_bounds_safety_unique_traps);
// Diagnose uses of legacy `-funique-traps` flags.
// TODO(dliew): Remove this once all uses of the legacy flag are removed
// (rdar://162215869).
if (Arg *A =
Args.getLastArg(options::OPT_fbounds_safety_legacy_unique_traps,
options::OPT_fno_bounds_safety_legacy_unique_traps)) {

StringRef ReplacementArg;
if (A->getOption().matches(options::OPT_fbounds_safety_legacy_unique_traps))
ReplacementArg = getDriverOptTable().getOptionName(
options::OPT_fbounds_safety_unique_traps);
else
ReplacementArg = getDriverOptTable().getOptionName(
options::OPT_fno_bounds_safety_unique_traps);
D.Diag(diag::warn_drv_deprecated_arg)
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Can we make sure that this warning doesn't trigger as an error for the project using this flag?

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Yes we should do that but as a separate task to landing this fix here.

<< A->getSpelling() << 1 << ReplacementArg;
}

// Pass the flag to enable unique traps if necessary. This handles both the
// legacy and new flag name for unique traps such that the old flags are
// treated as aliases of the new flags.
// TODO(dliew): Remove support for the legacy flag (rdar://162215869).
if (Arg *A =
Args.getLastArg(options::OPT_fbounds_safety_unique_traps,
options::OPT_fno_bounds_safety_unique_traps,
options::OPT_fbounds_safety_legacy_unique_traps,
options::OPT_fno_bounds_safety_legacy_unique_traps)) {

// Note we only pass the flag for enabling unique traps to cc1. It isn't
// necessary to pass the flag to disable unique traps because it is cc1's
// default behavior.
if (A->getOption().matches(options::OPT_fbounds_safety_unique_traps) ||
A->getOption().matches(
options::OPT_fbounds_safety_legacy_unique_traps)) {
CmdArgs.push_back("-fbounds-safety-unique-traps");
}
}
/* TO_UPSTREAM(BoundsSafety) OFF*/

// Handle -f[no-]wrapv and -f[no-]strict-overflow, which are used by both
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20 changes: 20 additions & 0 deletions clang/test/BoundsSafety/Driver/unique-traps-legacy-flag.c
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@@ -0,0 +1,20 @@
// Simple use of legacy flag
// RUN: %clang -fbounds-safety -funique-traps -### %s 2>&1 | FileCheck --check-prefix=POS %s
// RUN: %clang -fbounds-safety -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=NEG %s

// Mix legacy flag with new flag
// RUN: %clang -fbounds-safety -funique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=POS %s
// RUN: %clang -fbounds-safety -fno-unique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=NEG %s

// Last legacy flag wins for warning
// RUN: %clang -fbounds-safety -funique-traps -fno-unique-traps -funique-traps -### %s 2>&1 | FileCheck --check-prefix=POS %s
// RUN: %clang -fbounds-safety -funique-traps -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=NEG %s

// No warning
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=NONE %s
// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=NONE %s
// RUN: %clang -fbounds-safety -### %s 2>&1 | FileCheck --check-prefix=NONE %s

// POS: warning: argument '-funique-traps' is deprecated, use 'fbounds-safety-unique-traps' instead [-Wdeprecated]
// NEG: warning: argument '-fno-unique-traps' is deprecated, use 'fno-bounds-safety-unique-traps' instead [-Wdeprecated]
// NONE-NOT: warning: argument '-f{{(no-)?}}unique-traps' is deprecated
38 changes: 38 additions & 0 deletions clang/test/BoundsSafety/Driver/unique-traps.c
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@@ -0,0 +1,38 @@
// RUN: %clang -fbounds-safety -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s

// Simple use of new flag
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s

// New flag used multiple times
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -fno-bounds-safety-unique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -fbounds-safety-unique-traps -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s

// Simple use of legacy flag
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s

// Legacy flag used multiple times
// RUN: %clang -fbounds-safety -funique-traps -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -fno-unique-traps -funique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -funique-traps -fno-unique-traps -funique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s
// RUN: %clang -fbounds-safety -fno-unique-traps -funique-traps -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s

// Mixed use of legacy and new flag
// RUN: %clang -fbounds-safety -funique-traps -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -funique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s

// RUN: %clang -fbounds-safety -fno-unique-traps -fno-bounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -fno-unique-traps -fbounds-safety-unique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s

// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -fbounds-safety-unique-traps -funique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s

// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -fno-unique-traps -### %s 2>&1 | FileCheck --check-prefix=DISABLED %s
// RUN: %clang -fbounds-safety -fno-bounds-safety-unique-traps -funique-traps -### %s 2>&1 | FileCheck --check-prefix=ENABLED %s


// ENABLED: -fbounds-safety-unique-traps
// DISABLED-NOT: -fbounds-safety-unique-traps