[PATCH] D116480: [DebugInfo] Avoid triggering global location assert for 2-byte pointer sizes.

Jack Andersen via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Jan 4 10:28:41 PST 2022


jackoalan updated this revision to Diff 397332.
jackoalan retitled this revision from "[DebugInfo] Support 2-byte addresses for global location attributes." to "[DebugInfo] Avoid triggering global location assert for 2-byte pointer sizes.".
jackoalan edited the summary of this revision.
jackoalan added a comment.

Sink assert using lambda


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D116480/new/

https://reviews.llvm.org/D116480

Files:
  llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
  llvm/test/DebugInfo/MSP430/global-var.ll


Index: llvm/test/DebugInfo/MSP430/global-var.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MSP430/global-var.ll
@@ -0,0 +1,47 @@
+; RUN: llc --filetype=obj -o %t < %s
+; RUN: llvm-dwarfdump --debug-info %t | FileCheck %s
+; RUN: llvm-dwarfdump --verify %t
+
+; CHECK:      DW_TAG_variable
+; CHECK-NEXT:   DW_AT_name      ("global_var")
+; CHECK-NEXT:   DW_AT_type      ({{0x[0-9]+}} "char")
+; CHECK-NEXT:   DW_AT_external  (true)
+; CHECK-NEXT:   DW_AT_decl_file ("/tmp{{[/\\]}}global-var.c")
+; CHECK-NEXT:   DW_AT_decl_line (1)
+; CHECK-NEXT:   DW_AT_location  (DW_OP_addr 0x0)
+
+; ModuleID = 'global-var.c'
+source_filename = "global-var.c"
+target datalayout = "e-m:e-p:16:16-i32:16-i64:16-f32:16-f64:16-a:8-n8:16-S16"
+target triple = "msp430"
+
+ at global_var = dso_local global i8 42, align 1, !dbg !0
+
+; Function Attrs: noinline nounwind optnone
+define dso_local i16 @main() #0 !dbg !10 {
+entry:
+  ret i16 0, !dbg !15
+}
+
+attributes #0 = { noinline nounwind optnone "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!6, !7, !8}
+!llvm.ident = !{!9}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "global_var", scope: !2, file: !3, line: 1, type: !5, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 14.0.0 (https://github.com/llvm/llvm-project ...)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "global-var.c", directory: "/tmp")
+!4 = !{!0}
+!5 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!6 = !{i32 7, !"Dwarf Version", i32 4}
+!7 = !{i32 2, !"Debug Info Version", i32 3}
+!8 = !{i32 1, !"wchar_size", i32 2}
+!9 = !{!"clang version 14.0.0 (https://github.com/llvm/llvm-project ...)"}
+!10 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 2, type: !11, scopeLine: 2, spFlags: DISPFlagDefinition, unit: !2, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocation(line: 2, column: 13, scope: !10)
Index: llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -260,9 +260,14 @@
 
     if (Global) {
       const MCSymbol *Sym = Asm->getSymbol(Global);
-      unsigned PointerSize = Asm->getDataLayout().getPointerSize();
-      assert((PointerSize == 4 || PointerSize == 8) &&
-             "Add support for other sizes if necessary");
+      // 16-bit platforms like MSP430 and AVR take this path, so sink this
+      // assert to platforms that use it.
+      auto GetPointerSize = [this]() {
+        unsigned PointerSize = Asm->getDataLayout().getPointerSize();
+        assert((PointerSize == 4 || PointerSize == 8) &&
+               "Add support for other sizes if necessary");
+        return PointerSize;
+      };
       if (Global->isThreadLocal()) {
         if (Asm->TM.useEmulatedTLS()) {
           // TODO: add debug info for emulated thread local mode.
@@ -270,6 +275,7 @@
           // FIXME: Make this work with -gsplit-dwarf.
           // Based on GCC's support for TLS:
           if (!DD->useSplitDwarf()) {
+            unsigned PointerSize = GetPointerSize();
             // 1) Start with a constNu of the appropriate pointer size
             addUInt(*Loc, dwarf::DW_FORM_data1,
                     PointerSize == 4 ? dwarf::DW_OP_const4u
@@ -292,6 +298,7 @@
         }
       } else if (Asm->TM.getRelocationModel() == Reloc::RWPI ||
                  Asm->TM.getRelocationModel() == Reloc::ROPI_RWPI) {
+        unsigned PointerSize = GetPointerSize();
         // Constant
         addUInt(*Loc, dwarf::DW_FORM_data1,
                 PointerSize == 4 ? dwarf::DW_OP_const4u


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