Use DILexicalBlockFile, rather than DILexicalBlock, to track discriminator changes to ensure discriminator changes don't introduce new DWARF DW_TAG_lexical_blocks.

Somewhat unnoticed in the original implementation of discriminators, but
it could cause instructions to end up in new, small,
DW_TAG_lexical_blocks due to the use of DILexicalBlock to track
discriminator changes.

Instead, use DILexicalBlockFile which we already use to track file
changes without introducing new scopes, so it works well to track
discriminator changes in the same way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216239 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Blaikie
2014-08-21 22:45:21 +00:00
parent d1a09c47d2
commit c7260209a8
16 changed files with 47 additions and 52 deletions
+3 -5
View File
@@ -320,7 +320,6 @@ Block descriptors
metadata, ;; Reference to context descriptor
i32, ;; Line number
i32, ;; Column number
i32, ;; DWARF path discriminator value
i32 ;; Unique ID to identify blocks from a template function
}
@@ -334,6 +333,7 @@ lexical blocks at same depth.
i32, ;; Tag = 11 (DW_TAG_lexical_block)
metadata, ;; Source directory (including trailing slash) & file pair
metadata ;; Reference to the scope we're annotating with a file change
i32, ;; DWARF path discriminator value
}
This descriptor provides a wrapper around a lexical scope to handle file
@@ -733,8 +733,7 @@ Compiled to LLVM, this function would be represented like this:
!15 = metadata !{i32 786688, metadata !16, metadata !"Z", metadata !5, i32 5,
metadata !11, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [Z] \
[line 5]
!16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0,
i32 0} \
!16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0} \
; [ DW_TAG_lexical_block ] [/private/tmp/t.c]
!17 = metadata !{i32 5, i32 0, metadata !16, null}
!18 = metadata !{i32 6, i32 0, metadata !16, null}
@@ -786,8 +785,7 @@ scope information for the variable ``Z``.
.. code-block:: llvm
!16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0,
i32 0}
!16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0} \
; [ DW_TAG_lexical_block ] [/private/tmp/t.c]
!17 = metadata !{i32 5, i32 0, metadata !16, null}