From 3dadff7d01f0aee731be960b60970d4f5fd8b32b Mon Sep 17 00:00:00 2001 From: Nicholas Bishop Date: Thu, 1 Oct 2026 19:17:49 +0000 Subject: [PATCH] Fix lowering crash when a SpecificInst's inst_id doesn't emit a value (#7880) --- toolchain/lower/function_context.cpp | 17 +- toolchain/lower/function_context.h | 8 +- toolchain/lower/handle.cpp | 8 +- .../lower/testdata/template/class.carbon | 178 ++++++++++++++++++ 4 files changed, 205 insertions(+), 6 deletions(-) create mode 100644 toolchain/lower/testdata/template/class.carbon diff --git a/toolchain/lower/function_context.cpp b/toolchain/lower/function_context.cpp index bc3984faad76..6d2574fb27b4 100644 --- a/toolchain/lower/function_context.cpp +++ b/toolchain/lower/function_context.cpp @@ -174,7 +174,8 @@ auto FunctionContext::IsConstant(SemIR::InstId inst_id) -> bool { .second.is_constant(); } -auto FunctionContext::GetValue(SemIR::InstId inst_id) -> llvm::Value* { +auto FunctionContext::GetValue(SemIR::InstId inst_id, bool require_value) + -> llvm::Value* { // Singletons are types, as is the builtin TypeType, with the same empty // lowered value. if (SemIR::IsSingletonInstId(inst_id) || @@ -193,9 +194,17 @@ auto FunctionContext::GetValue(SemIR::InstId inst_id) -> llvm::Value* { auto [const_ir, const_id] = GetConstantValueInSpecific( specific_sem_ir(), specific_id_, sem_ir(), inst_id); CARBON_CHECK(const_ir == &sem_ir() || const_ir == &specific_sem_ir()); - CARBON_CHECK(const_id.is_concrete(), - "Missing value: {0} {1} in {2} has non-concrete value {3}", - inst_id, sem_ir().insts().Get(inst_id), specific_id_, const_id); + if (require_value) { + CARBON_CHECK(const_id.is_concrete(), + "Missing value: {0} {1} in {2} has non-concrete value {3}", + inst_id, sem_ir().insts().Get(inst_id), specific_id_, + const_id); + } + + if (!const_id.is_concrete()) { + return nullptr; + } + // We can only pass on the InstId if it refers to the file in which the // constant value was provided. auto* global = GetFileContext(const_ir).GetConstant( diff --git a/toolchain/lower/function_context.h b/toolchain/lower/function_context.h index 1ee62e34bfb6..4b2144e419b2 100644 --- a/toolchain/lower/function_context.h +++ b/toolchain/lower/function_context.h @@ -116,7 +116,13 @@ class FunctionContext { auto IsConstant(SemIR::InstId) -> bool; // Returns a value for the given instruction. - auto GetValue(SemIR::InstId inst_id) -> llvm::Value*; + // + // If `require_value` is true, the instruction is required to have emitted a + // value or have a concrete constant in the current specific, and will CHECK + // if these conditions are not met. If `require_value` is false, `nullptr` + // will be returned instead if there is no value for the instruction. + auto GetValue(SemIR::InstId inst_id, bool require_value = true) + -> llvm::Value*; // Sets the value for the given instruction. auto SetLocal(SemIR::InstId inst_id, llvm::Value* value) -> void { diff --git a/toolchain/lower/handle.cpp b/toolchain/lower/handle.cpp index 2a71fb3b874a..30bd9a405957 100644 --- a/toolchain/lower/handle.cpp +++ b/toolchain/lower/handle.cpp @@ -363,7 +363,13 @@ auto HandleInst(FunctionContext& context, SemIR::InstId inst_id, CARBON_CHECK(&context.sem_ir() == &context.specific_sem_ir() && context.specific_id() == inst.specific_id, "Runtime specific_inst refers to a different specific"); - context.SetLocal(inst_id, context.GetValue(inst.inst_id)); + + // When lowering templates, the specific may contain instructions that + // neither emit a value during lowering nor have a constant value, so set + // require_value=false. + if (auto* value = context.GetValue(inst.inst_id, /*require_value=*/false)) { + context.SetLocal(inst_id, value); + } } auto HandleInst(FunctionContext& context, SemIR::InstId inst_id, diff --git a/toolchain/lower/testdata/template/class.carbon b/toolchain/lower/testdata/template/class.carbon new file mode 100644 index 000000000000..63ed7cfc2e82 --- /dev/null +++ b/toolchain/lower/testdata/template/class.carbon @@ -0,0 +1,178 @@ +// Part of the Carbon Language project, under the Apache License v2.0 with LLVM +// Exceptions. See /LICENSE for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/convert.carbon +// +// AUTOUPDATE +// TIP: To test this file alone, run: +// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/template/class.carbon +// TIP: To dump output, run: +// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/template/class.carbon + +// --- init_class.carbon +library "[[@TEST_NAME]]"; + +class B { + impl as Core.Copy { + fn Op(unused self) -> Self { + return {}; + } + } +} + +class A(template T: type) { + fn Make(v: T) -> A(T) { + return { + .field = v, + }; + } + + var field: T; +} + +fn Run() { + A(B).Make({}); +} + +// CHECK:STDOUT: ; --- +// CHECK:STDOUT: ; ModuleID = 'init_class.carbon' +// CHECK:STDOUT: source_filename = "init_class.carbon" +// CHECK:STDOUT: +// CHECK:STDOUT: @B.val = internal constant {} zeroinitializer +// CHECK:STDOUT: @B.val.loc6_16 = internal constant {} zeroinitializer +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define void @"_COp.B.Main:Copy.Core"(ptr sret({}) %return, ptr %self) #0 !dbg !24 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %return, ptr align 1 @B.val.loc6_16, i64 0, i1 false), !dbg !29 +// CHECK:STDOUT: ret void, !dbg !29 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define i32 @main() #0 !dbg !31 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: %.loc22_15.1.temp = alloca { {} }, align 1, !dbg !32 +// CHECK:STDOUT: %.loc22_14.2.temp = alloca {}, align 1, !dbg !33 +// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc22_15.1.temp), !dbg !32 +// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc22_14.2.temp), !dbg !33 +// CHECK:STDOUT: call void @_CMake.A.Main.a6a60dfee2d7d273(ptr %.loc22_15.1.temp, ptr @B.val.loc6_16), !dbg !32 +// CHECK:STDOUT: call void @"_CSelfDestruct.d32110776493a13a:core.Destroy.Core"(ptr %.loc22_15.1.temp), !dbg !32 +// CHECK:STDOUT: call void @"_CSelfDestruct.8c4b83ecd900f1ea:core.Destroy.Core"(ptr @B.val), !dbg !33 +// CHECK:STDOUT: ret i32 0, !dbg !34 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSelfDestruct.cb8adced19392b99:core.Destroy.Core"(ptr %self) #0 !dbg !35 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: ret void, !dbg !37 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSelfDestruct.8c4b83ecd900f1ea:core.Destroy.Core"(ptr %self) #0 !dbg !39 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: ret void, !dbg !41 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSubobjectDestroy.8fbe0c6a865381a4:core.Destroy.Core"(ptr %self) #0 !dbg !43 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: %.loc22.field = getelementptr inbounds nuw { {} }, ptr %self, i32 0, i32 0, !dbg !45 +// CHECK:STDOUT: call void @"_CSelfDestruct.8c4b83ecd900f1ea:core.Destroy.Core"(ptr %.loc22.field), !dbg !45 +// CHECK:STDOUT: ret void, !dbg !45 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSelfDestruct.8fbe0c6a865381a4:core.Destroy.Core"(ptr %self) #0 !dbg !47 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: call void @"_CSubobjectDestroy.8fbe0c6a865381a4:core.Destroy.Core"(ptr %self), !dbg !49 +// CHECK:STDOUT: ret void, !dbg !49 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSubobjectDestroy.d32110776493a13a:core.Destroy.Core"(ptr %self) #0 !dbg !51 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: ret void, !dbg !53 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define weak_odr void @"_CSelfDestruct.d32110776493a13a:core.Destroy.Core"(ptr %self) #0 !dbg !55 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: call void @"_CSubobjectDestroy.d32110776493a13a:core.Destroy.Core"(ptr %self), !dbg !57 +// CHECK:STDOUT: ret void, !dbg !57 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) +// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1 +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) +// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1 +// CHECK:STDOUT: +// CHECK:STDOUT: ; Function Attrs: nounwind +// CHECK:STDOUT: define linkonce_odr void @_CMake.A.Main.a6a60dfee2d7d273(ptr sret({ {} }) %return, ptr %v) #0 !dbg !59 { +// CHECK:STDOUT: entry: +// CHECK:STDOUT: %.b3e.field = getelementptr inbounds nuw { {} }, ptr %return, i32 0, i32 0, !dbg !65 +// CHECK:STDOUT: call void @"_COp.B.Main:Copy.Core"(ptr %.b3e.field, ptr %v), !dbg !64 +// CHECK:STDOUT: ret void, !dbg !66 +// CHECK:STDOUT: } +// CHECK:STDOUT: +// CHECK:STDOUT: ; uselistorder directives +// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 } +// CHECK:STDOUT: +// CHECK:STDOUT: attributes #0 = { nounwind } +// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) } +// CHECK:STDOUT: +// CHECK:STDOUT: !llvm.dbg.cu = !{!15} +// CHECK:STDOUT: !llvm.module.flags = !{!2, !3} +// CHECK:STDOUT: +// CHECK:STDOUT: !2 = !{i32 7, !"Dwarf Version", i32 5} +// CHECK:STDOUT: !3 = !{i32 2, !"Debug Info Version", i32 3} +// CHECK:STDOUT: !14 = !DIFile(filename: "init_class.carbon", directory: "") +// CHECK:STDOUT: !15 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !14, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug) +// CHECK:STDOUT: !16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64) +// CHECK:STDOUT: !17 = !{!16, !16} +// CHECK:STDOUT: !18 = !DISubroutineType(types: !17) +// CHECK:STDOUT: !19 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +// CHECK:STDOUT: !20 = !{!19} +// CHECK:STDOUT: !21 = !DISubroutineType(types: !20) +// CHECK:STDOUT: !22 = !{null, !16} +// CHECK:STDOUT: !23 = !DISubroutineType(types: !22) +// CHECK:STDOUT: !24 = distinct !DISubprogram(name: "Op", linkageName: "_COp.B.Main:Copy.Core", scope: null, file: !14, line: 5, type: !18, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !30) +// CHECK:STDOUT: !25 = !DILocalVariable(arg: 1, scope: !24, type: !16) +// CHECK:STDOUT: !29 = !DILocation(line: 6, column: 7, scope: !24) +// CHECK:STDOUT: !30 = !{!25} +// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !14, line: 21, type: !21, spFlags: DISPFlagDefinition, unit: !15) +// CHECK:STDOUT: !32 = !DILocation(line: 22, column: 3, scope: !31) +// CHECK:STDOUT: !33 = !DILocation(line: 22, column: 13, scope: !31) +// CHECK:STDOUT: !34 = !DILocation(line: 21, column: 1, scope: !31) +// CHECK:STDOUT: !35 = distinct !DISubprogram(name: "SelfDestruct", linkageName: "_CSelfDestruct.cb8adced19392b99:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !38) +// CHECK:STDOUT: !36 = !DILocalVariable(arg: 1, scope: !35, type: !16) +// CHECK:STDOUT: !37 = !DILocation(line: 22, column: 3, scope: !35) +// CHECK:STDOUT: !38 = !{!36} +// CHECK:STDOUT: !39 = distinct !DISubprogram(name: "SelfDestruct", linkageName: "_CSelfDestruct.8c4b83ecd900f1ea:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !42) +// CHECK:STDOUT: !40 = !DILocalVariable(arg: 1, scope: !39, type: !16) +// CHECK:STDOUT: !41 = !DILocation(line: 22, column: 3, scope: !39) +// CHECK:STDOUT: !42 = !{!40} +// CHECK:STDOUT: !43 = distinct !DISubprogram(name: "SubobjectDestroy", linkageName: "_CSubobjectDestroy.8fbe0c6a865381a4:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !46) +// CHECK:STDOUT: !44 = !DILocalVariable(arg: 1, scope: !43, type: !16) +// CHECK:STDOUT: !45 = !DILocation(line: 22, column: 3, scope: !43) +// CHECK:STDOUT: !46 = !{!44} +// CHECK:STDOUT: !47 = distinct !DISubprogram(name: "SelfDestruct", linkageName: "_CSelfDestruct.8fbe0c6a865381a4:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !50) +// CHECK:STDOUT: !48 = !DILocalVariable(arg: 1, scope: !47, type: !16) +// CHECK:STDOUT: !49 = !DILocation(line: 22, column: 3, scope: !47) +// CHECK:STDOUT: !50 = !{!48} +// CHECK:STDOUT: !51 = distinct !DISubprogram(name: "SubobjectDestroy", linkageName: "_CSubobjectDestroy.d32110776493a13a:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !54) +// CHECK:STDOUT: !52 = !DILocalVariable(arg: 1, scope: !51, type: !16) +// CHECK:STDOUT: !53 = !DILocation(line: 22, column: 3, scope: !51) +// CHECK:STDOUT: !54 = !{!52} +// CHECK:STDOUT: !55 = distinct !DISubprogram(name: "SelfDestruct", linkageName: "_CSelfDestruct.d32110776493a13a:core.Destroy.Core", scope: null, file: !14, line: 22, type: !23, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !58) +// CHECK:STDOUT: !56 = !DILocalVariable(arg: 1, scope: !55, type: !16) +// CHECK:STDOUT: !57 = !DILocation(line: 22, column: 3, scope: !55) +// CHECK:STDOUT: !58 = !{!56} +// CHECK:STDOUT: !59 = distinct !DISubprogram(name: "Make", linkageName: "_CMake.A.Main.a6a60dfee2d7d273", scope: null, file: !14, line: 12, type: !18, spFlags: DISPFlagDefinition, unit: !15, retainedNodes: !67) +// CHECK:STDOUT: !60 = !DILocalVariable(arg: 1, scope: !59, type: !16) +// CHECK:STDOUT: !64 = !DILocation(line: 14, column: 16, scope: !59) +// CHECK:STDOUT: !65 = !DILocation(line: 13, column: 12, scope: !59) +// CHECK:STDOUT: !66 = !DILocation(line: 13, column: 5, scope: !59) +// CHECK:STDOUT: !67 = !{!60} +// CHECK:STDOUT: