auto merge of #14486 : michaelwoerister/rust/unified_enum_rep, r=luqmana

So far the DWARF information for enums was different for regular enums, univariant enums, Option-like enums, etc. Regular enums were encoded as unions of structs, while the other variants were encoded as bare structs. With the changes in this PR all enums are encoded as unions so that debuggers can reconstruct if something originally was a struct, a univariant enum, or an Option-like enum.  For the latter case, information about the *Null* variant is encoded into the union field name. This information can then be used by the debugger to print a `None` value actually as `None` instead of `Some(0x0)`.

The changes in this PR should also fix the regression reported in #14385 and #14411, but I want to close these only after I have confirmation from the original reporters that the issues are actually fixed for them.

10 files changed, 25 insertions, 23 deletions

diff --git a/src/test/debuginfo/borrowed-enum.rs b/src/test/debuginfo/borrowed-enum.rs
index 7126aec2391..a377d68a33d 100644
--- a/src/test/debuginfo/borrowed-enum.rs
+++ b/src/test/debuginfo/borrowed-enum.rs
@@ -22,7 +22,7 @@
 // gdb-check:$2 = {{TheB, x = 0, y = 1229782938247303441}, {TheB, 0, 286331153, 286331153}}
 
 // gdb-command:print *univariant_ref
-// gdb-check:$3 = {4820353753753434}
+// gdb-check:$3 = {{4820353753753434}}
 
 #![allow(unused_variable)]
 #![feature(struct_variant)]
diff --git a/src/test/debuginfo/generic-struct-style-enum.rs b/src/test/debuginfo/generic-struct-style-enum.rs
index 498d0981e35..eddf4dfd755 100644
--- a/src/test/debuginfo/generic-struct-style-enum.rs
+++ b/src/test/debuginfo/generic-struct-style-enum.rs
@@ -27,7 +27,7 @@
 // gdb-check:$3 = {{Case3, a = 0, b = 22873, c = 22873, d = 22873, e = 22873}, {Case3, a = 0, b = 1499027801, c = 1499027801}, {Case3, a = 0, b = 6438275382588823897}}
 
 // gdb-command:print univariant
-// gdb-check:$4 = {a = -1}
+// gdb-check:$4 = {{a = -1}}
 
 #![feature(struct_variant)]
 
diff --git a/src/test/debuginfo/generic-tuple-style-enum.rs b/src/test/debuginfo/generic-tuple-style-enum.rs
index 16a665ca8c6..07f7546068c 100644
--- a/src/test/debuginfo/generic-tuple-style-enum.rs
+++ b/src/test/debuginfo/generic-tuple-style-enum.rs
@@ -27,7 +27,7 @@
 // gdb-check:$3 = {{Case3, 0, 22873, 22873, 22873, 22873}, {Case3, 0, 1499027801, 1499027801}, {Case3, 0, 6438275382588823897}}
 
 // gdb-command:print univariant
-// gdb-check:$4 = {-1}
+// gdb-check:$4 = {{-1}}
 
 
 // NOTE: This is a copy of the non-generic test case. The `Txx` type parameters have to be
diff --git a/src/test/debuginfo/managed-enum.rs b/src/test/debuginfo/managed-enum.rs
index 7899e0c6a9b..36e75812deb 100644
--- a/src/test/debuginfo/managed-enum.rs
+++ b/src/test/debuginfo/managed-enum.rs
@@ -22,7 +22,7 @@
 // gdb-check:$2 = {{TheB, x = 0, y = 1229782938247303441}, {TheB, 0, 286331153, 286331153}}
 
 // gdb-command:print univariant->val
-// gdb-check:$3 = {-9747455}
+// gdb-check:$3 = {{-9747455}}
 
 #![allow(unused_variable)]
 #![feature(struct_variant, managed_boxes)]
diff --git a/src/test/debuginfo/option-like-enum.rs b/src/test/debuginfo/option-like-enum.rs
index 803d0aed593..04cd7e13863 100644
--- a/src/test/debuginfo/option-like-enum.rs
+++ b/src/test/debuginfo/option-like-enum.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-tidy-linelength
 // ignore-android: FIXME(#10381)
 
 // compile-flags:-g
@@ -16,19 +17,19 @@
 // gdb-command:finish
 
 // gdb-command:print some
-// gdb-check:$1 = (u32 *) 0x12345678
+// gdb-check:$1 = {RUST$ENCODED$ENUM$0$None = {0x12345678}}
 
 // gdb-command:print none
-// gdb-check:$2 = (u32 *) 0x0
+// gdb-check:$2 = {RUST$ENCODED$ENUM$0$None = {0x0}}
 
 // gdb-command:print full
-// gdb-check:$3 = {454545, 0x87654321, 9988}
+// gdb-check:$3 = {RUST$ENCODED$ENUM$1$Empty = {454545, 0x87654321, 9988}}
 
 // gdb-command:print empty->discr
 // gdb-check:$4 = (int *) 0x0
 
 // gdb-command:print droid
-// gdb-check:$5 = {id = 675675, range = 10000001, internals = 0x43218765}
+// gdb-check:$5 = {RUST$ENCODED$ENUM$2$Void = {id = 675675, range = 10000001, internals = 0x43218765}}
 
 // gdb-command:print void_droid->internals
 // gdb-check:$6 = (int *) 0x0
diff --git a/src/test/debuginfo/recursive-struct.rs b/src/test/debuginfo/recursive-struct.rs
index aa13072eb53..518ef62fe9a 100644
--- a/src/test/debuginfo/recursive-struct.rs
+++ b/src/test/debuginfo/recursive-struct.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-tidy-linelength
 // ignore-android: FIXME(#10381)
 
 #![feature(managed_boxes)]
@@ -20,53 +21,53 @@
 
 // gdb-command:print stack_unique.value
 // gdb-check:$1 = 0
-// gdb-command:print stack_unique.next->value
+// gdb-command:print stack_unique.next.RUST$ENCODED$ENUM$0$Empty.val->value
 // gdb-check:$2 = 1
 
 // gdb-command:print unique_unique->value
 // gdb-check:$3 = 2
-// gdb-command:print unique_unique->next->value
+// gdb-command:print unique_unique->next.RUST$ENCODED$ENUM$0$Empty.val->value
 // gdb-check:$4 = 3
 
 // gdb-command:print box_unique->val.value
 // gdb-check:$5 = 4
-// gdb-command:print box_unique->val.next->value
+// gdb-command:print box_unique->val.next.RUST$ENCODED$ENUM$0$Empty.val->value
 // gdb-check:$6 = 5
 
 // gdb-command:print vec_unique[0].value
 // gdb-check:$7 = 6.5
-// gdb-command:print vec_unique[0].next->value
+// gdb-command:print vec_unique[0].next.RUST$ENCODED$ENUM$0$Empty.val->value
 // gdb-check:$8 = 7.5
 
 // gdb-command:print borrowed_unique->value
 // gdb-check:$9 = 8.5
-// gdb-command:print borrowed_unique->next->value
+// gdb-command:print borrowed_unique->next.RUST$ENCODED$ENUM$0$Empty.val->value
 // gdb-check:$10 = 9.5
 
 // MANAGED
 // gdb-command:print stack_managed.value
 // gdb-check:$11 = 10
-// gdb-command:print stack_managed.next.val->value
+// gdb-command:print stack_managed.next.RUST$ENCODED$ENUM$0$Empty.val->val.value
 // gdb-check:$12 = 11
 
 // gdb-command:print unique_managed->value
 // gdb-check:$13 = 12
-// gdb-command:print unique_managed->next.val->value
+// gdb-command:print unique_managed->next.RUST$ENCODED$ENUM$0$Empty.val->val.value
 // gdb-check:$14 = 13
 
 // gdb-command:print box_managed.val->value
 // gdb-check:$15 = 14
-// gdb-command:print box_managed->val->next.val->value
+// gdb-command:print box_managed->val->next.RUST$ENCODED$ENUM$0$Empty.val->val.value
 // gdb-check:$16 = 15
 
 // gdb-command:print vec_managed[0].value
 // gdb-check:$17 = 16.5
-// gdb-command:print vec_managed[0].next.val->value
+// gdb-command:print vec_managed[0].next.RUST$ENCODED$ENUM$0$Empty.val->val.value
 // gdb-check:$18 = 17.5
 
 // gdb-command:print borrowed_managed->value
 // gdb-check:$19 = 18.5
-// gdb-command:print borrowed_managed->next.val->value
+// gdb-command:print borrowed_managed->next.RUST$ENCODED$ENUM$0$Empty.val->val.value
 // gdb-check:$20 = 19.5
 
 // LONG CYCLE
@@ -97,7 +98,7 @@
 // gdb-command:print (*****long_cycle_w_anonymous_types).value
 // gdb-check:$31 = 30
 
-// gdb-command:print (*****((*****long_cycle_w_anonymous_types).next)).value
+// gdb-command:print (*****((*****long_cycle_w_anonymous_types).next.RUST$ENCODED$ENUM$0$Empty.val)).value
 // gdb-check:$32 = 31
 
 // gdb-command:continue
diff --git a/src/test/debuginfo/struct-in-enum.rs b/src/test/debuginfo/struct-in-enum.rs
index ee971d71cfc..0cba56ad320 100644
--- a/src/test/debuginfo/struct-in-enum.rs
+++ b/src/test/debuginfo/struct-in-enum.rs
@@ -24,7 +24,7 @@
 // gdb-check:$2 = {{Case2, 0, {x = 286331153, y = 286331153, z = 4369}}, {Case2, 0, 1229782938247303441, 4369}}
 
 // gdb-command:print univariant
-// gdb-check:$3 = {{x = 123, y = 456, z = 789}}
+// gdb-check:$3 = {{{x = 123, y = 456, z = 789}}}
 
 #![allow(unused_variable)]
 
diff --git a/src/test/debuginfo/struct-style-enum.rs b/src/test/debuginfo/struct-style-enum.rs
index 1a51db1a005..70d4d709d23 100644
--- a/src/test/debuginfo/struct-style-enum.rs
+++ b/src/test/debuginfo/struct-style-enum.rs
@@ -27,7 +27,7 @@
 // gdb-check:$3 = {{Case3, a = 0, b = 22873, c = 22873, d = 22873, e = 22873}, {Case3, a = 0, b = 1499027801, c = 1499027801}, {Case3, a = 0, b = 6438275382588823897}}
 
 // gdb-command:print univariant
-// gdb-check:$4 = {a = -1}
+// gdb-check:$4 = {{a = -1}}
 
 #![allow(unused_variable)]
 #![feature(struct_variant)]
diff --git a/src/test/debuginfo/tuple-style-enum.rs b/src/test/debuginfo/tuple-style-enum.rs
index dc922b45005..81c72d16886 100644
--- a/src/test/debuginfo/tuple-style-enum.rs
+++ b/src/test/debuginfo/tuple-style-enum.rs
@@ -27,7 +27,7 @@
 // gdb-check:$3 = {{Case3, 0, 22873, 22873, 22873, 22873}, {Case3, 0, 1499027801, 1499027801}, {Case3, 0, 6438275382588823897}}
 
 // gdb-command:print univariant
-// gdb-check:$4 = {-1}
+// gdb-check:$4 = {{-1}}
 
 #![allow(unused_variable)]
 
diff --git a/src/test/debuginfo/unique-enum.rs b/src/test/debuginfo/unique-enum.rs
index f85ec6a8da3..3949a315adc 100644
--- a/src/test/debuginfo/unique-enum.rs
+++ b/src/test/debuginfo/unique-enum.rs
@@ -22,7 +22,7 @@
 // gdb-check:$2 = {{TheB, x = 0, y = 1229782938247303441}, {TheB, 0, 286331153, 286331153}}
 
 // gdb-command:print *univariant
-// gdb-check:$3 = {123234}
+// gdb-check:$3 = {{123234}}
 
 #![allow(unused_variable)]
 #![feature(struct_variant)]