https://github.com/nataliakokoromyti updated https://github.com/llvm/llvm-project/pull/177096
>From 989b9b695193cf5e48f5676edbb262acc5b4378f Mon Sep 17 00:00:00 2001 From: Natalia Kokoromyti <[email protected]> Date: Tue, 20 Jan 2026 19:38:52 -0800 Subject: [PATCH 01/11] fix crash on u8 string --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 4 ++++ clang/lib/Sema/SemaStmtAsm.cpp | 5 ++++- clang/test/Sema/asm-no-crash-non-ordinary-string.cpp | 7 +++++++ 3 files changed, 15 insertions(+), 1 deletion(-) create mode 100644 clang/test/Sema/asm-no-crash-non-ordinary-string.cpp diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 44541a4c68197..935e896653fda 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9906,6 +9906,10 @@ let CategoryName = "Inline Assembly Issue" in { def err_asm_operand_empty_string : Error< "cannot use an empty string literal in 'asm'">; + def err_asm_string_literal_not_ordinary : Error< + "cannot use unicode string literal in 'asm'">; + + def err_asm_pmf_through_constraint_not_permitted : Error<"cannot pass a pointer-to-member through register-constrained " "inline assembly parameter">; diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp index f957bdf7156c7..8f39872fb5b3e 100644 --- a/clang/lib/Sema/SemaStmtAsm.cpp +++ b/clang/lib/Sema/SemaStmtAsm.cpp @@ -240,7 +240,10 @@ ExprResult Sema::ActOnGCCAsmStmtString(Expr *Expr, bool ForAsmLabel) { return ExprError(); if (auto *SL = dyn_cast<StringLiteral>(Expr)) { - assert(SL->isOrdinary()); + if (!SL->isOrdinary()) { + Diag(SL->getBeginLoc(), diag::err_asm_string_literal_not_ordinary); + return ExprError(); + } if (ForAsmLabel && SL->getString().empty()) { Diag(Expr->getBeginLoc(), diag::err_asm_operand_empty_string) << SL->getSourceRange(); diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp new file mode 100644 index 0000000000000..42a2f30db9138 --- /dev/null +++ b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp @@ -0,0 +1,7 @@ +// RUN: not %clang_cc1 -fsyntax-only -verify %s + +void foo() { + asm("" ::: (u8""})); + // expected-error@-1 {{cannot use unicode string literal in 'asm'}} + // expected-error@-2 {{expected ')'}} +} >From a5def4857a329357999520b37efd4fd55fe9ec1c Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 20:15:34 -0800 Subject: [PATCH 02/11] address feedback --- clang/docs/ReleaseNotes.rst | 1 + clang/include/clang/Basic/DiagnosticCommonKinds.td | 3 +++ clang/include/clang/Basic/DiagnosticParseKinds.td | 2 -- clang/include/clang/Basic/DiagnosticSemaKinds.td | 3 --- clang/lib/Sema/SemaStmtAsm.cpp | 2 +- clang/test/Sema/asm-no-crash-non-ordinary-string.cpp | 11 ++++++++++- 6 files changed, 15 insertions(+), 7 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 611e3fba2bc2b..83cdcf685a31e 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -127,6 +127,7 @@ Improvements to Coverage Mapping Bug Fixes in This Version ------------------------- +- Fixed a crash when using non-ordinary string literals (``u8""``, ``L""``, ``u""``, ``U""``) in inline assembly. Clang now properly diagnoses these as errors. (#GH177056) Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/include/clang/Basic/DiagnosticCommonKinds.td b/clang/include/clang/Basic/DiagnosticCommonKinds.td index 6e50e225a8cc1..fd1fe4979508a 100644 --- a/clang/include/clang/Basic/DiagnosticCommonKinds.td +++ b/clang/include/clang/Basic/DiagnosticCommonKinds.td @@ -305,6 +305,9 @@ def err_asm_invalid_type_in_input : Error< def err_asm_invalid_type : Error< "invalid type %0 in asm %select{input|output}1">; +def err_asm_operand_wide_string_literal : Error< + "cannot use %select{unicode|wide}0 string literal in 'asm'">; + def err_ms_asm_bitfield_unsupported : Error< "an inline asm block cannot have an operand which is a bit-field">; diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td index 457d3644de35a..ecb3aa9b8ab25 100644 --- a/clang/include/clang/Basic/DiagnosticParseKinds.td +++ b/clang/include/clang/Basic/DiagnosticParseKinds.td @@ -348,8 +348,6 @@ def warn_cxx20_compat_label_end_of_compound_statement : Warning< InGroup<CXXPre23Compat>, DefaultIgnore; def err_address_of_label_outside_fn : Error< "use of address-of-label extension outside of a function body">; -def err_asm_operand_wide_string_literal : Error< - "cannot use %select{unicode|wide}0 string literal in 'asm'">; def err_defer_ts_labeled_stmt : Error< "substatement of defer must not be a label">; diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 935e896653fda..b6d0d51e268fe 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9906,9 +9906,6 @@ let CategoryName = "Inline Assembly Issue" in { def err_asm_operand_empty_string : Error< "cannot use an empty string literal in 'asm'">; - def err_asm_string_literal_not_ordinary : Error< - "cannot use unicode string literal in 'asm'">; - def err_asm_pmf_through_constraint_not_permitted : Error<"cannot pass a pointer-to-member through register-constrained " diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp index 8f39872fb5b3e..34ec64c33aab9 100644 --- a/clang/lib/Sema/SemaStmtAsm.cpp +++ b/clang/lib/Sema/SemaStmtAsm.cpp @@ -241,7 +241,7 @@ ExprResult Sema::ActOnGCCAsmStmtString(Expr *Expr, bool ForAsmLabel) { if (auto *SL = dyn_cast<StringLiteral>(Expr)) { if (!SL->isOrdinary()) { - Diag(SL->getBeginLoc(), diag::err_asm_string_literal_not_ordinary); + Diag(SL->getBeginLoc(), diag::err_asm_operand_wide_string_literal << (SL->isWide() ? 1 : 0)); return ExprError(); } if (ForAsmLabel && SL->getString().empty()) { diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp index 42a2f30db9138..996464526064d 100644 --- a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp +++ b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp @@ -1,7 +1,16 @@ -// RUN: not %clang_cc1 -fsyntax-only -verify %s +// RUN: %clang_cc1 -fsyntax-only -verify %s void foo() { asm("" ::: (u8""})); // expected-error@-1 {{cannot use unicode string literal in 'asm'}} // expected-error@-2 {{expected ')'}} } + +void test_other_literals() { + asm(L""); // expected-error {{cannot use wide string literal in 'asm'}} + asm(u""); // expected-error {{cannot use unicode string literal in 'asm'}} + asm(U""); // expected-error {{cannot use unicode string literal in 'asm'}} + + // Raw string literals should be accepted (they're still ordinary strings) + asm(R"(nop)"); +} >From 6300cef442d71d885ef0d4aade5f68c17c7dfd76 Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 20:26:50 -0800 Subject: [PATCH 03/11] fix format --- clang/lib/Sema/SemaStmtAsm.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp index 34ec64c33aab9..f7502eb108f53 100644 --- a/clang/lib/Sema/SemaStmtAsm.cpp +++ b/clang/lib/Sema/SemaStmtAsm.cpp @@ -241,7 +241,8 @@ ExprResult Sema::ActOnGCCAsmStmtString(Expr *Expr, bool ForAsmLabel) { if (auto *SL = dyn_cast<StringLiteral>(Expr)) { if (!SL->isOrdinary()) { - Diag(SL->getBeginLoc(), diag::err_asm_operand_wide_string_literal << (SL->isWide() ? 1 : 0)); + Diag(SL->getBeginLoc(), + diag::err_asm_operand_wide_string_literal << (SL->isWide() ? 1 : 0)); return ExprError(); } if (ForAsmLabel && SL->getString().empty()) { >From b2446468c707060be9513e8e8dfc8f52e7131383 Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 20:27:32 -0800 Subject: [PATCH 04/11] rm line Co-authored-by: Mariya Podchishchaeva <[email protected]> --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 1 - 1 file changed, 1 deletion(-) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index b6d0d51e268fe..44541a4c68197 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9906,7 +9906,6 @@ let CategoryName = "Inline Assembly Issue" in { def err_asm_operand_empty_string : Error< "cannot use an empty string literal in 'asm'">; - def err_asm_pmf_through_constraint_not_permitted : Error<"cannot pass a pointer-to-member through register-constrained " "inline assembly parameter">; >From de8fdcacd5f72e7a4e33eefe1a567cd82fafc0c1 Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 20:39:04 -0800 Subject: [PATCH 05/11] rm whitespace --- clang/lib/Sema/SemaStmtAsm.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp index f7502eb108f53..c4876c4db48c8 100644 --- a/clang/lib/Sema/SemaStmtAsm.cpp +++ b/clang/lib/Sema/SemaStmtAsm.cpp @@ -241,7 +241,7 @@ ExprResult Sema::ActOnGCCAsmStmtString(Expr *Expr, bool ForAsmLabel) { if (auto *SL = dyn_cast<StringLiteral>(Expr)) { if (!SL->isOrdinary()) { - Diag(SL->getBeginLoc(), + Diag(SL->getBeginLoc(), diag::err_asm_operand_wide_string_literal << (SL->isWide() ? 1 : 0)); return ExprError(); } >From 5f65626d667185c71b4479e4feec7ab4a5b53c50 Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 23:25:06 -0800 Subject: [PATCH 06/11] fix call to match parser expectation --- clang/lib/Sema/SemaStmtAsm.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp index c4876c4db48c8..15d81e7547971 100644 --- a/clang/lib/Sema/SemaStmtAsm.cpp +++ b/clang/lib/Sema/SemaStmtAsm.cpp @@ -241,8 +241,8 @@ ExprResult Sema::ActOnGCCAsmStmtString(Expr *Expr, bool ForAsmLabel) { if (auto *SL = dyn_cast<StringLiteral>(Expr)) { if (!SL->isOrdinary()) { - Diag(SL->getBeginLoc(), - diag::err_asm_operand_wide_string_literal << (SL->isWide() ? 1 : 0)); + Diag(SL->getBeginLoc(), diag::err_asm_operand_wide_string_literal) + << SL->isWide() << SL->getSourceRange(); return ExprError(); } if (ForAsmLabel && SL->getString().empty()) { >From 422b0b4f974f532e380a2337712490cdb09ff405 Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 23:36:42 -0800 Subject: [PATCH 07/11] fix test to expect all parser errors --- clang/test/Sema/asm-no-crash-non-ordinary-string.cpp | 2 ++ 1 file changed, 2 insertions(+) diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp index 996464526064d..d589d8cafca4b 100644 --- a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp +++ b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp @@ -4,6 +4,8 @@ void foo() { asm("" ::: (u8""})); // expected-error@-1 {{cannot use unicode string literal in 'asm'}} // expected-error@-2 {{expected ')'}} + // expected-note@-3 {{to match this '('}} + // expected-error@-4 {{expected expression}} } void test_other_literals() { >From c59118b636f7a873acce566ad63a033480d6e7bc Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Wed, 21 Jan 2026 23:53:13 -0800 Subject: [PATCH 08/11] put all errors on same line --- clang/test/Sema/asm-no-crash-non-ordinary-string.cpp | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp index d589d8cafca4b..3e9bdae83df9c 100644 --- a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp +++ b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp @@ -1,11 +1,7 @@ // RUN: %clang_cc1 -fsyntax-only -verify %s void foo() { - asm("" ::: (u8""})); - // expected-error@-1 {{cannot use unicode string literal in 'asm'}} - // expected-error@-2 {{expected ')'}} - // expected-note@-3 {{to match this '('}} - // expected-error@-4 {{expected expression}} + asm("" ::: (u8"")); // expected-error {{cannot use unicode string literal in 'asm'}} expected-error {{expected ')'}} expected-note {{to match this '('}} expected-error {{expected expression}} } void test_other_literals() { >From 12b040565135349378398ed3b6e3a8ab5b2bee6d Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Thu, 22 Jan 2026 00:17:13 -0800 Subject: [PATCH 09/11] fix test to expect correct error message for parenthesized case --- clang/test/Sema/asm-no-crash-non-ordinary-string.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp index 3e9bdae83df9c..884def5785363 100644 --- a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp +++ b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp @@ -1,13 +1,15 @@ // RUN: %clang_cc1 -fsyntax-only -verify %s void foo() { - asm("" ::: (u8"")); // expected-error {{cannot use unicode string literal in 'asm'}} expected-error {{expected ')'}} expected-note {{to match this '('}} expected-error {{expected expression}} + // Test the crash case from GH177056 - this specific syntax triggered the assert + asm("" ::: (u8"")); // expected-error {{the expression in this asm operand must be a string literal or an object with 'data()' and 'size()' member functions}} } void test_other_literals() { asm(L""); // expected-error {{cannot use wide string literal in 'asm'}} asm(u""); // expected-error {{cannot use unicode string literal in 'asm'}} asm(U""); // expected-error {{cannot use unicode string literal in 'asm'}} + asm(u8""); // expected-error {{cannot use unicode string literal in 'asm'}} // Raw string literals should be accepted (they're still ordinary strings) asm(R"(nop)"); >From f5c53f0d429021ef701fd14c5746e84d2054b03d Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Thu, 22 Jan 2026 01:01:22 -0800 Subject: [PATCH 10/11] integrate test to existing asm.c file --- .../Sema/asm-no-crash-non-ordinary-string.cpp | 16 ---------------- clang/test/Sema/asm.c | 4 ++++ 2 files changed, 4 insertions(+), 16 deletions(-) delete mode 100644 clang/test/Sema/asm-no-crash-non-ordinary-string.cpp diff --git a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp b/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp deleted file mode 100644 index 884def5785363..0000000000000 --- a/clang/test/Sema/asm-no-crash-non-ordinary-string.cpp +++ /dev/null @@ -1,16 +0,0 @@ -// RUN: %clang_cc1 -fsyntax-only -verify %s - -void foo() { - // Test the crash case from GH177056 - this specific syntax triggered the assert - asm("" ::: (u8"")); // expected-error {{the expression in this asm operand must be a string literal or an object with 'data()' and 'size()' member functions}} -} - -void test_other_literals() { - asm(L""); // expected-error {{cannot use wide string literal in 'asm'}} - asm(u""); // expected-error {{cannot use unicode string literal in 'asm'}} - asm(U""); // expected-error {{cannot use unicode string literal in 'asm'}} - asm(u8""); // expected-error {{cannot use unicode string literal in 'asm'}} - - // Raw string literals should be accepted (they're still ordinary strings) - asm(R"(nop)"); -} diff --git a/clang/test/Sema/asm.c b/clang/test/Sema/asm.c index a666b45b3150c..5340f8265c4d1 100644 --- a/clang/test/Sema/asm.c +++ b/clang/test/Sema/asm.c @@ -43,6 +43,10 @@ void test3(void) { int x; asm(L"foo" : "=r"(x)); // expected-error {{wide string}} asm("foo" : L"=r"(x)); // expected-error {{wide string}} + + // GH177056 + asm("" ::: (u8"")); // expected-error {{the expression in this asm operand must be a string literal or an object with 'data()' and 'size()' member functions}} + asm(R"(nop)"); } void test4(const volatile void *addr) >From f62dd5b594da938f275b997cff17589b1b1b7b0c Mon Sep 17 00:00:00 2001 From: nataliakokoromyti <[email protected]> Date: Thu, 22 Jan 2026 01:19:42 -0800 Subject: [PATCH 11/11] fix error message --- clang/test/Sema/asm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/test/Sema/asm.c b/clang/test/Sema/asm.c index 5340f8265c4d1..b6c64777166fc 100644 --- a/clang/test/Sema/asm.c +++ b/clang/test/Sema/asm.c @@ -45,7 +45,7 @@ void test3(void) { asm("foo" : L"=r"(x)); // expected-error {{wide string}} // GH177056 - asm("" ::: (u8"")); // expected-error {{the expression in this asm operand must be a string literal or an object with 'data()' and 'size()' member functions}} + asm("" ::: (u8"")); // expected-error {{expected string literal in 'asm'}} expected-error {{expected ')'}} asm(R"(nop)"); } _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
