Revert "Revert "DI: Fold constant arguments into a single MDString""

This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 219010

1 files changed, 18 insertions, 20 deletions

diff --git a/llvm/test/CodeGen/ARM/debug-segmented-stacks.ll b/llvm/test/CodeGen/ARM/debug-segmented-stacks.ll
index e866b4e124d..2123fa7a2f9 100644
--- a/llvm/test/CodeGen/ARM/debug-segmented-stacks.ll
+++ b/llvm/test/CodeGen/ARM/debug-segmented-stacks.ll
@@ -39,39 +39,37 @@ define void @test_basic() #0 {
 ; ARM-linux       .cfi_same_value r5
 }
 
-!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [/tmp/var.c] [DW_LANG_C99]
+!0 = metadata !{metadata !"0x11\0012\00clang version 3.5 \000\00\000\00\000", metadata !1, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2} ; [ DW_TAG_compile_unit ] [/tmp/var.c] [DW_LANG_C99]
 !1 = metadata !{metadata !"var.c", metadata !"/tmp"}
 !2 = metadata !{}
 !3 = metadata !{metadata !4}
-!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"test_basic",
-  metadata !"test_basic", metadata !"", i32 5, metadata !6, i1 false, i1 true,
-  i32 0, i32 0, null, i32 256, i1 false, void ()* @test_basic, null, null, metadata !2, i32 5} ; [ DW_TAG_subprogram ] [line 5] [def] [sum]
-!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/tmp/var.c]
-!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!4 = metadata !{metadata !"0x2e\00test_basic\00test_basic\00\005\000\001\000\006\00256\000\005", metadata !1, metadata !5, metadata !6, null, void ()* @test_basic, null, null, metadata !2} ; [ DW_TAG_subprogram ] [line 5] [def] [sum]
+!5 = metadata !{metadata !"0x29", metadata !1}          ; [ DW_TAG_file_type ] [/tmp/var.c]
+!6 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", i32 0, null, null, metadata !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
 !7 = metadata !{metadata !8, metadata !8}
-!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!8 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
 !9 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
-!10 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!10 = metadata !{i32 1, metadata !"Debug Info Version", i32 2}
 !11 = metadata !{metadata !"clang version 3.5 "}
-!12 = metadata !{i32 786689, metadata !4, metadata !"count", metadata !5, i32 16777221, metadata !8, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [count] [line 5]
+!12 = metadata !{metadata !"0x101\00count\0016777221\000", metadata !4, metadata !5, metadata !8} ; [ DW_TAG_arg_variable ] [count] [line 5]
 !13 = metadata !{i32 5, i32 0, metadata !4, null}
-!14 = metadata !{i32 786688, metadata !4, metadata !"vl", metadata !5, i32 6, metadata !15, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [vl] [line 6]
-!15 = metadata !{i32 786454, metadata !16, null, metadata !"va_list", i32 30, i64 0, i64 0, i64 0, i32 0, metadata !17} ; [ DW_TAG_typedef ] [va_list] [line 30, size 0, align 0, offset 0] [from __builtin_va_list]
+!14 = metadata !{metadata !"0x100\00vl\006\000", metadata !4, metadata !5, metadata !15} ; [ DW_TAG_auto_variable ] [vl] [line 6]
+!15 = metadata !{metadata !"0x16\00va_list\0030\000\000\000\000", metadata !16, null, metadata !17} ; [ DW_TAG_typedef ] [va_list] [line 30, size 0, align 0, offset 0] [from __builtin_va_list]
 !16 = metadata !{metadata !"/linux-x86_64-high/gcc_4.7.2/dbg/llvm/bin/../lib/clang/3.5/include/stdarg.h", metadata !"/tmp"}
-!17 = metadata !{i32 786454, metadata !1, null, metadata !"__builtin_va_list", i32 6, i64 0, i64 0, i64 0, i32 0, metadata !18} ; [ DW_TAG_typedef ] [__builtin_va_list] [line 6, size 0, align 0, offset 0] [from __va_list]
-!18 = metadata !{i32 786451, metadata !1, null, metadata !"__va_list", i32 6, i64 32, i64 32, i32 0, i32 0, null, metadata !19, i32 0, null, null, null} ; [ DW_TAG_structure_type ] [__va_list] [line 6, size 32, align 32, offset 0] [def] [from ]
+!17 = metadata !{metadata !"0x16\00__builtin_va_list\006\000\000\000\000", metadata !1, null, metadata !18} ; [ DW_TAG_typedef ] [__builtin_va_list] [line 6, size 0, align 0, offset 0] [from __va_list]
+!18 = metadata !{metadata !"0x13\00__va_list\006\0032\0032\000\000\000", metadata !1, null, null, metadata !19, null, null, null} ; [ DW_TAG_structure_type ] [__va_list] [line 6, size 32, align 32, offset 0] [def] [from ]
 !19 = metadata !{metadata !20}
-!20 = metadata !{i32 786445, metadata !1, metadata !18, metadata !"__ap", i32 6, i64 32, i64 32, i64 0, i32 0, metadata !21} ; [ DW_TAG_member ] [__ap] [line 6, size 32, align 32, offset 0] [from ]
-!21 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 32, i64 32, i64 0, i32 0, null} ; [ DW_TAG_pointer_type ] [line 0, size 32, align 32, offset 0] [from ]
+!20 = metadata !{metadata !"0xd\00__ap\006\0032\0032\000\000", metadata !1, metadata !18, metadata !21} ; [ DW_TAG_member ] [__ap] [line 6, size 32, align 32, offset 0] [from ]
+!21 = metadata !{metadata !"0xf\00\000\0032\0032\000\000", null, null, null} ; [ DW_TAG_pointer_type ] [line 0, size 32, align 32, offset 0] [from ]
 !22 = metadata !{i32 6, i32 0, metadata !4, null}
 !23 = metadata !{i32 7, i32 0, metadata !4, null}
-!24 = metadata !{i32 786688, metadata !4, metadata !"test_basic", metadata !5, i32 8, metadata !8, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [sum] [line 8]
-!25 = metadata !{i32 8, i32 0, metadata !4, null} ; [ DW_TAG_imported_declaration ]
-!26 = metadata !{i32 786688, metadata !27, metadata !"i", metadata !5, i32 9, metadata !8, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [i] [line 9]
-!27 = metadata !{i32 786443, metadata !1, metadata !4, i32 9, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/tmp/var.c]
+!24 = metadata !{metadata !"0x100\00test_basic\008\000", metadata !4, metadata !5, metadata !8} ; [ DW_TAG_auto_variable ] [sum] [line 8]
+!25 = metadata !{i32 8, i32 0, metadata !4, null}
+!26 = metadata !{metadata !"0x100\00i\009\000", metadata !27, metadata !5, metadata !8} ; [ DW_TAG_auto_variable ] [i] [line 9]
+!27 = metadata !{metadata !"0xb\009\000\000", metadata !1, metadata !4} ; [ DW_TAG_lexical_block ] [/tmp/var.c]
 !28 = metadata !{i32 9, i32 0, metadata !27, null}
 !29 = metadata !{i32 10, i32 0, metadata !30, null}
-!30 = metadata !{i32 786443, metadata !1, metadata !27, i32 9, i32 0, i32 1} ; [ DW_TAG_lexical_block ] [/tmp/var.c]
+!30 = metadata !{metadata !"0xb\009\000\001", metadata !1, metadata !27} ; [ DW_TAG_lexical_block ] [/tmp/var.c]
 !31 = metadata !{i32 11, i32 0, metadata !30, null}
 !32 = metadata !{i32 12, i32 0, metadata !4, null}
 !33 = metadata !{i32 13, i32 0, metadata !4, null}