.debug_gnu_pub{names,types}: Stabilize iteration order

StringMap iteration order is not guaranteed to be deterministic
(https://llvm.org/docs/ProgrammersManual.html#llvm-adt-stringmap-h).
Sort by DIE offset (which looks like a pre-order traversal order).

Author: MaskRay

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -2549,10 +2549,13 @@ void DwarfDebug::emitDebugPubSection(bool GnuStyle, StringRef Name,
   Asm->emitDwarfLengthOrOffset(TheU->getLength());
 
   // Emit the pubnames for this compilation unit.
-  for (const auto &GI : Globals) {
-    const char *Name = GI.getKeyData();
-    const DIE *Entity = GI.second;
-
+  SmallVector<std::pair<StringRef, const DIE *>, 0> Vec;
+  for (const auto &GI : Globals)
+    Vec.emplace_back(GI.first(), GI.second);
+  llvm::sort(Vec, [](auto &A, auto &B) {
+    return A.second->getOffset() < B.second->getOffset();
+  });
+  for (const auto &[Name, Entity] : Vec) {
     Asm->OutStreamer->AddComment("DIE offset");
     Asm->emitDwarfLengthOrOffset(Entity->getOffset());
 
@@ -2565,7 +2568,7 @@ void DwarfDebug::emitDebugPubSection(bool GnuStyle, StringRef Name,
     }
 
     Asm->OutStreamer->AddComment("External Name");
-    Asm->OutStreamer->emitBytes(StringRef(Name, GI.getKeyLength() + 1));
+    Asm->OutStreamer->emitBytes(StringRef(Name.data(), Name.size() + 1));
   }
 
   Asm->OutStreamer->AddComment("End Mark");

llvm/test/DebugInfo/X86/debug-pubtables-dwarf64.ll

@@ -19,8 +19,8 @@
 ; CHECK:      .debug_pubtypes contents:
 ; CHECK-NEXT: length = 0x0000000000000032, format = DWARF64, version = 0x0002, unit_offset =
 ; CHECK-NEXT: Offset     Name
-; CHECK-NEXT: 0x00000000[[BASET]] "int"
 ; CHECK-NEXT: 0x00000000[[STRUCT]] "Foo"
+; CHECK-NEXT: 0x00000000[[BASET]] "int"
 
 ; IR generated and reduced from:
 ; $ cat foo.c

llvm/test/DebugInfo/X86/gnu-public-names-gmlt.ll

@@ -17,8 +17,8 @@
 ; GPUB: .debug_gnu_pubnames contents:
 ; GPUB-NEXT: unit_offset = 0x00000000
 ; GPUB-NEXT: Name
-; GPUB-NEXT: "f3"
 ; GPUB-NEXT: "f2"
+; GPUB-NEXT: "f3"
 
 ; GPUB: .debug_gnu_pubtypes contents:
 ; GPUB-NEXT: length = 0x0000000e, format = DWARF32, version = 0x0002, unit_offset = 0x00000000

llvm/test/DebugInfo/X86/gnu-public-names-tu.ll

@@ -25,8 +25,8 @@
 ; CHECK-LABEL: debug_gnu_pubtypes contents:
 ; CHECK-NEXT: length = {{.*}}, version = 0x0002, unit_offset = 0x00000000, unit_size = {{.*}}
 ; CHECK-NEXT: Offset     Linkage  Kind     Name
-; CHECK-NEXT: [[BAR]]    EXTERNAL TYPE     "bar"
 ; CHECK-NEXT: [[CU]]     EXTERNAL TYPE     "ns::foo"
+; CHECK-NEXT: [[BAR]]    EXTERNAL TYPE     "bar"
 
 %struct.bar = type { %"struct.ns::foo" }
 %"struct.ns::foo" = type { i8 }

llvm/test/DebugInfo/X86/gnu-public-names.ll

@@ -66,9 +66,11 @@
 
 ; ASM: .section        .debug_gnu_pubnames
 ; ASM: .byte   32                      # Attributes: VARIABLE, EXTERNAL
-; ASM-NEXT: .asciz  "ns::global_namespace_variable"       # External Name
+; ASM-NEXT: .asciz  "C::static_member_variable"           # External Name
 ; ASM: .byte   32                      # Attributes: VARIABLE, EXTERNAL
 ; ASM-NEXT: .asciz  "global_variable"       # External Name
+; ASM: .byte   32                      # Attributes: VARIABLE, EXTERNAL
+; ASM-NEXT: .asciz  "ns::global_namespace_variable"       # External Name
 
 ; ASM: .section        .debug_gnu_pubtypes
 ; ASM: .byte   16                      # Attributes: TYPE, EXTERNAL
@@ -196,42 +198,42 @@
 ; CHECK-LABEL: .debug_gnu_pubnames contents:
 ; CHECK-NEXT: length = {{.*}}, version = 0x0002, unit_offset = 0x00000000, unit_size = {{.*}}
 ; CHECK-NEXT: Offset     Linkage  Kind     Name
-; CHECK-NEXT:  [[ANON_INNER_B]] STATIC VARIABLE "(anonymous namespace)::inner::b"
-; CHECK-NEXT:  [[MEM_FUNC]] EXTERNAL FUNCTION "C::member_function"
-; CHECK-NEXT:  [[OUTER]] EXTERNAL TYPE "outer"
-; CHECK-NEXT:  [[GLOB_NS_VAR]] EXTERNAL VARIABLE "ns::global_namespace_variable"
+; CHECK-NEXT:  [[STATIC_MEM_VAR]] EXTERNAL VARIABLE "C::static_member_variable"
 ; CHECK-NEXT:  [[GLOB_VAR]] EXTERNAL VARIABLE "global_variable"
-; CHECK-NEXT:  [[UNNAMED_ENUM_ENUMERATOR]] STATIC VARIABLE  "unnamed_enum_enumerator"
-; CHECK-NEXT:  [[GLOBAL_F7]] EXTERNAL FUNCTION "f7"
-; CHECK-NEXT:  [[OUTER_ANON]] EXTERNAL TYPE "outer::(anonymous namespace)"
-; FIXME: GCC produces enumerators as EXTERNAL, not STATIC
-; CHECK-NEXT:  [[NAMED_ENUM_CLASS_ENUMERATOR]] STATIC VARIABLE  "named_enum_class_enumerator"
-; CHECK-NEXT:  [[GLOBAL_FUNC]] EXTERNAL FUNCTION "global_function"
-; CHECK-NEXT:  [[GLOB_NS_FUNC]] EXTERNAL FUNCTION "ns::global_namespace_function"
 ; CHECK-NEXT:  [[NS]] EXTERNAL TYPE     "ns"
-; CHECK-NEXT:  [[NAMED_ENUM_ENUMERATOR]] STATIC VARIABLE  "named_enum_enumerator"
-; CHECK-NEXT:  [[ANON]] EXTERNAL TYPE "(anonymous namespace)"
-; CHECK-NEXT:  [[OUTER_ANON_C]] STATIC VARIABLE "outer::(anonymous namespace)::c"
+; CHECK-NEXT:  [[GLOB_NS_VAR]] EXTERNAL VARIABLE "ns::global_namespace_variable"
 ; CHECK-NEXT:  [[D_VAR]] EXTERNAL VARIABLE "ns::d"
-; CHECK-NEXT:  [[STATIC_MEM_FUNC]] EXTERNAL FUNCTION "C::static_member_function"
-; CHECK-NEXT:  [[STATIC_MEM_VAR]] EXTERNAL VARIABLE "C::static_member_variable"
-; CHECK-NEXT:  [[ANON_I]] STATIC VARIABLE "(anonymous namespace)::i"
-; CHECK-NEXT:  [[ANON_INNER]] EXTERNAL TYPE "(anonymous namespace)::inner"
+; CHECK-NEXT:  [[GLOB_NS_FUNC]] EXTERNAL FUNCTION "ns::global_namespace_function"
 ; CHECK-NEXT:  [[F3]] EXTERNAL FUNCTION "f3"
 ; GCC Doesn't put local statics in pubnames, but it seems not unreasonable and
 ; comes out naturally from LLVM's implementation, so I'm OK with it for now. If
 ; it's demonstrated that this is a major size concern or degrades debug info
 ; consumer behavior, feel free to change it.
 ; CHECK-NEXT:  [[F3_Z]] STATIC VARIABLE "f3::z"
+; CHECK-NEXT:  [[ANON]] EXTERNAL TYPE "(anonymous namespace)"
+; CHECK-NEXT:  [[ANON_I]] STATIC VARIABLE "(anonymous namespace)::i"
+; CHECK-NEXT:  [[ANON_INNER]] EXTERNAL TYPE "(anonymous namespace)::inner"
+; CHECK-NEXT:  [[ANON_INNER_B]] STATIC VARIABLE "(anonymous namespace)::inner::b"
+; CHECK-NEXT:  [[OUTER]] EXTERNAL TYPE "outer"
+; CHECK-NEXT:  [[OUTER_ANON]] EXTERNAL TYPE "outer::(anonymous namespace)"
+; CHECK-NEXT:  [[OUTER_ANON_C]] STATIC VARIABLE "outer::(anonymous namespace)::c"
+; CHECK-NEXT:  [[UNNAMED_ENUM_ENUMERATOR]] STATIC VARIABLE  "unnamed_enum_enumerator"
+; CHECK-NEXT:  [[NAMED_ENUM_ENUMERATOR]] STATIC VARIABLE  "named_enum_enumerator"
+; CHECK-NEXT:  [[NAMED_ENUM_CLASS_ENUMERATOR]] STATIC VARIABLE  "named_enum_class_enumerator"
+; CHECK-NEXT:  [[MEM_FUNC]] EXTERNAL FUNCTION "C::member_function"
+; CHECK-NEXT:  [[STATIC_MEM_FUNC]] EXTERNAL FUNCTION "C::static_member_function"
+; FIXME: GCC produces enumerators as EXTERNAL, not STATIC
+; CHECK-NEXT:  [[GLOBAL_FUNC]] EXTERNAL FUNCTION "global_function"
+; CHECK-NEXT:  [[GLOBAL_F7]] EXTERNAL FUNCTION "f7"
 
 ; CHECK-LABEL: debug_gnu_pubtypes contents:
 ; CHECK: Offset     Linkage  Kind     Name
-; CHECK-NEXT:  [[INT]] STATIC   TYPE     "int"
 ; CHECK-NEXT:  [[C]] EXTERNAL TYPE     "C"
+; CHECK-NEXT:  [[INT]] STATIC   TYPE     "int"
+; CHECK-NEXT:  [[D]] EXTERNAL TYPE     "ns::D"
 ; CHECK-NEXT:  [[UNSIGNED_INT]] STATIC   TYPE     "unsigned int"
 ; CHECK-NEXT:  [[NAMED_ENUM]] EXTERNAL TYPE     "named_enum"
 ; CHECK-NEXT:  [[NAMED_ENUM_CLASS]] EXTERNAL TYPE     "named_enum_class"
-; CHECK-NEXT:  [[D]] EXTERNAL TYPE     "ns::D"
 
 %struct.C = type { i8 }
 %"struct.ns::D" = type { i32 }