[llvm] [NVPTX] mangle symbols in debug info to conform to PTX restrictions. (PR #113216)

[Artem Belevich via llvm-commits]

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@@ -0,0 +1,42 @@
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_60 | FileCheck %s
+; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_60 | %ptxas-verify %}
+target datalayout = "e-i64:64-i128:128-v16:16-v32:32-n16:32:64"
+target triple = "nvptx64-nvidia-cuda"
+
+; Verify that the symbols with the characters illegal in PTX get appropriately mangled.
+ at __PRETTY_FUNCTION__._Z3foov = private unnamed_addr constant [11 x i8] c"void foo()\00", align 1, !dbg !0
+; '.' gets replaced with `_$_`.
+; CHECK: .global .align 1 .b8 __PRETTY_FUNCTION___$__Z3foov[11] = {118, 111, 105, 100, 32, 102, 111, 111, 40, 41};
+
+; .debug* section names are special and are allowed to have the leading dot.
+; CHECK-DAG: .section        .debug_abbrev
+; CHECK-DAG: .section        .debug_info
+; CHECK-DAG: .b32 .debug_abbrev
+; CHECK-DAG: .b32 .debug_line
+; CHECK-DAG: .section        .debug_macinfo
+
+; .. but the symbol name must be mangled the same way here as it was at the definition point.
+; CHECK-DAG: .b64 __PRETTY_FUNCTION___$__Z3foov
+;
+
+!llvm.dbg.cu = !{!8}
+!llvm.module.flags = !{!10, !11, !12}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(scope: null, file: !2, line: 1, type: !3, isLocal: true, isDefinition: true)
+!2 = !DIFile(filename: "<stdin>", directory: "/usr/local/google/home/tra/work/llvm/build/release+assert+zapcc/dbg-dot")
+!3 = !DICompositeType(tag: DW_TAG_array_type, baseType: !4, size: 88, elements: !6)
+!4 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !5)
+!5 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!6 = !{!7}
+!7 = !DISubrange(count: 11)
+!8 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !2, producer: "clang version 20.0.0git", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !9, splitDebugInlining: false, nameTableKind: None)
+!9 = !{!0}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{i32 4, !"nvvm-reflect-ftz", i32 0}
+!13 = !{!"clang version 20.0.0git"}
----------------
Artem-B wrote:

TBH, I do not know enough about dwarf generation internals, to tell whether some of the metadata w/o explicit references is needed or not, so I left clang-generated IR as is.

https://github.com/llvm/llvm-project/pull/113216