for (const ArangeSpan &Span : List) {
Asm->emitLabelReference(Span.Start, PtrSize);
- // Calculate the size as being from the span start to it's end.
- if (Span.End) {
+ // Calculate the size as being from the span start to its end.
+ //
+ // If the size is zero, then round it up to one byte. The DWARF
+ // specification requires that entries in this table have nonzero
+ // lengths.
+ auto SizeRef = SymSize.find(Span.Start);
+ if ((SizeRef == SymSize.end() || SizeRef->second != 0) && Span.End) {
Asm->emitLabelDifference(Span.End, Span.Start, PtrSize);
} else {
// For symbols without an end marker (e.g. common), we
// write a single arange entry containing just that one symbol.
- uint64_t Size = SymSize[Span.Start];
- if (Size == 0)
+ uint64_t Size;
+ if (SizeRef == SymSize.end() || SizeRef->second == 0)
Size = 1;
+ else
+ Size = SizeRef->second;
Asm->OutStreamer->emitIntValue(Size, PtrSize);
}
--- /dev/null
+; Ensures that the compiler doesn't assert when DWARF aranges are enabled in the presence of
+; `available_externally` constants.
+
+; Generated from the following C++ source:
+;
+; template <typename T>
+; struct Baz {
+; static constexpr int boo = int(-1);
+; };
+;
+; extern template struct Baz<char>;
+;
+; void bar(const int& a);
+;
+; void foo() {
+; bar(Baz<char>::boo);
+; }
+;
+; Compiled with:
+;
+; $ clang -cc1 -triple=x86_64-unknown-linux-gnu -debug-info-kind=standalone \
+; -mllvm -generate-arange-section -std=c++17 foo.cpp
+
+; RUN: llc --generate-arange-section < %s
+
+; ModuleID = 'reduced2.cpp'
+source_filename = "reduced2.cpp"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@_ZN3BazIcE3booE = available_externally constant i32 -1, align 4, !dbg !0
+
+; Function Attrs: mustprogress noinline nounwind optnone
+define dso_local void @_Z3foov() #0 !dbg !17 {
+entry:
+ call void @_Z3barRKi(ptr noundef nonnull align 4 dereferenceable(4) @_ZN3BazIcE3booE), !dbg !21
+ ret void, !dbg !22
+}
+
+declare void @_Z3barRKi(ptr noundef nonnull align 4 dereferenceable(4)) #1
+
+attributes #0 = { mustprogress noinline nounwind optnone "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+attributes #1 = { "frame-pointer"="none" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!14, !15}
+!llvm.ident = !{!16}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "boo", linkageName: "_ZN3BazIcE3booE", scope: !2, file: !5, line: 3, type: !6, isLocal: false, isDefinition: true, declaration: !8)
+!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !3, producer: "clang version 15.0.0 (https://github.com/llvm/llvm-project.git 2f52a868225755ebfa5242992d3a650ac6aadce7)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "<stdin>", directory: "/Users/pcwalton/Downloads")
+!4 = !{!0}
+!5 = !DIFile(filename: "reduced2.cpp", directory: "/Users/pcwalton/Downloads")
+!6 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !7)
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "boo", scope: !9, file: !5, line: 3, baseType: !6, flags: DIFlagStaticMember, extraData: i32 -1)
+!9 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Baz<char>", file: !5, line: 6, size: 8, flags: DIFlagTypePassByValue, elements: !10, templateParams: !11, identifier: "_ZTS3BazIcE")
+!10 = !{!8}
+!11 = !{!12}
+!12 = !DITemplateTypeParameter(name: "T", type: !13)
+!13 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{i32 1, !"wchar_size", i32 4}
+!16 = !{!"clang version 15.0.0 (https://github.com/llvm/llvm-project.git 2f52a868225755ebfa5242992d3a650ac6aadce7)"}
+!17 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !5, file: !5, line: 10, type: !18, scopeLine: 10, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !2, retainedNodes: !20)
+!18 = !DISubroutineType(types: !19)
+!19 = !{null}
+!20 = !{}
+!21 = !DILocation(line: 11, column: 3, scope: !17)
+!22 = !DILocation(line: 12, column: 1, scope: !17)
--- /dev/null
+; Ensures that the AsmPrinter rounds up zero-sized symbols in `.debug_aranges` to one byte.
+
+; Generated from the following Rust source:
+;
+; pub static EXAMPLE: () = ();
+;
+; Compiled with:
+;
+; $ rustc --crate-type=lib --target=x86_64-unknown-linux-gnu --emit=llvm-ir -g dwarf-aranges-zero-size.rs
+
+; RUN: llc --generate-arange-section < %s | FileCheck %s
+; CHECK: .section .debug_aranges
+; CHECK: .quad _ZN23dwarf_aranges_zero_size7EXAMPLE17h8ab19f2b0c3b238dE
+; CHECK-NEXT: .quad 1
+; CHECK: .section
+
+; ModuleID = 'dwarf_aranges_zero_size.fbc28187-cgu.0'
+source_filename = "dwarf_aranges_zero_size.fbc28187-cgu.0"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@_ZN23dwarf_aranges_zero_size7EXAMPLE17h8ab19f2b0c3b238dE = constant <{ [0 x i8] }> zeroinitializer, align 1, !dbg !0
+@__rustc_debug_gdb_scripts_section__ = linkonce_odr unnamed_addr constant [34 x i8] c"\01gdb_load_rust_pretty_printers.py\00", section ".debug_gdb_scripts", align 1
+
+!llvm.module.flags = !{!5, !6, !7}
+!llvm.dbg.cu = !{!8}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "EXAMPLE", linkageName: "_ZN23dwarf_aranges_zero_size7EXAMPLE17h8ab19f2b0c3b238dE", scope: !2, file: !3, line: 1, type: !4, isLocal: false, isDefinition: true, align: 8)
+!2 = !DINamespace(name: "dwarf_aranges_zero_size", scope: null)
+!3 = !DIFile(filename: "dwarf-aranges-zero-size.rs", directory: "/Users/pcwalton/Desktop", checksumkind: CSK_MD5, checksum: "c2d51547bfaf5562b9c9061311fe4140")
+!4 = !DIBasicType(name: "()", encoding: DW_ATE_unsigned)
+!5 = !{i32 7, !"PIC Level", i32 2}
+!6 = !{i32 2, !"RtLibUseGOT", i32 1}
+!7 = !{i32 2, !"Debug Info Version", i32 3}
+!8 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !9, producer: "clang LLVM (rustc version 1.60.0-nightly (0c292c966 2022-02-08))", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !10, globals: !11)
+!9 = !DIFile(filename: "dwarf-aranges-zero-size.rs/@/dwarf_aranges_zero_size.fbc28187-cgu.0", directory: "/Users/pcwalton/Desktop")
+!10 = !{}
+!11 = !{!0}