Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; RUN: llvm-link %s %S/Inputs/subprogram-linkonce-weak.ll -S -o %t1
|
|
|
|
|
; RUN: FileCheck %s -check-prefix=LW -check-prefix=CHECK <%t1
|
|
|
|
|
; RUN: llvm-link %S/Inputs/subprogram-linkonce-weak.ll %s -S -o %t2
|
|
|
|
|
; RUN: FileCheck %s -check-prefix=WL -check-prefix=CHECK <%t2
|
2015-09-16 13:34:32 +08:00
|
|
|
; REQUIRES: default_triple
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
|
|
|
|
|
; This testcase tests the following flow:
|
|
|
|
|
; - File A defines a linkonce version of @foo which has inlined into @bar.
|
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|
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|
; - File B defines a weak version of @foo (different definition).
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|
; - Linkage rules state File B version of @foo wins.
|
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|
; - @bar still has inlined debug info related to the linkonce @foo.
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;
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|
; This should fix PR22792, although the testcase was hand-written. There's a
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|
; RUN line with a crasher for llc at the end with checks for the DWARF output.
|
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|
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|
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|
; The LW prefix means linkonce (this file) first, then weak (the other file).
|
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|
; The WL prefix means weak (the other file) first, then linkonce (this file).
|
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|
|
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; We'll see @bar before @foo if this file is first.
|
2015-11-06 06:03:56 +08:00
|
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|
; LW: define i32 @bar({{.*}} !dbg ![[BARSP:[0-9]+]]
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; LW: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
|
|
|
|
|
; LW: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
|
2015-11-06 06:03:56 +08:00
|
|
|
; LW: define weak i32 @foo({{.*}} !dbg ![[WEAKFOOSP:[0-9]+]]
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; LW: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
|
|
|
|
|
; LW: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
|
|
|
|
|
|
|
|
|
|
; We'll see @foo before @bar if this file is second.
|
2015-11-06 06:03:56 +08:00
|
|
|
; WL: define weak i32 @foo({{.*}} !dbg ![[WEAKFOOSP:[0-9]+]]
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; WL: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
|
|
|
|
|
; WL: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
|
2015-11-06 06:03:56 +08:00
|
|
|
; WL: define i32 @bar({{.*}} !dbg ![[BARSP:[0-9]+]]
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; WL: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
|
|
|
|
|
; WL: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
|
|
|
|
|
|
2015-11-06 06:03:56 +08:00
|
|
|
define i32 @bar(i32 %a, i32 %b) !dbg !3 {
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
entry:
|
2015-04-30 00:38:44 +08:00
|
|
|
%sum = add i32 %a, %b, !dbg !DILocation(line: 2, scope: !4,
|
|
|
|
|
inlinedAt: !DILocation(line: 12, scope: !3))
|
|
|
|
|
ret i32 %sum, !dbg !DILocation(line: 13, scope: !3)
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
}
|
|
|
|
|
|
2015-11-06 06:03:56 +08:00
|
|
|
define linkonce i32 @foo(i32 %a, i32 %b) !dbg !4 {
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
entry:
|
2015-04-30 00:38:44 +08:00
|
|
|
%sum = add i32 %a, %b, !dbg !DILocation(line: 2, scope: !4)
|
|
|
|
|
ret i32 %sum, !dbg !DILocation(line: 3, scope: !4)
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
!llvm.module.flags = !{!0}
|
|
|
|
|
!0 = !{i32 2, !"Debug Info Version", i32 3}
|
|
|
|
|
|
|
|
|
|
; CHECK-LABEL: !llvm.dbg.cu =
|
|
|
|
|
; LW-SAME: !{![[LCU:[0-9]+]], ![[WCU:[0-9]+]]}
|
|
|
|
|
; WL-SAME: !{![[WCU:[0-9]+]], ![[LCU:[0-9]+]]}
|
|
|
|
|
!llvm.dbg.cu = !{!1}
|
|
|
|
|
|
2015-08-04 01:26:41 +08:00
|
|
|
; LW: ![[LCU]] = distinct !DICompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
|
2015-11-06 06:03:56 +08:00
|
|
|
; LW: ![[LSPs]] = !{![[BARSP]], ![[FOOSP:[0-9]+]]}
|
2015-08-29 04:26:49 +08:00
|
|
|
; LW: ![[BARSP]] = distinct !DISubprogram(name: "bar",
|
|
|
|
|
; LW: ![[FOOSP]] = distinct !DISubprogram(name: "foo",
|
2015-08-04 01:26:41 +08:00
|
|
|
; LW: ![[WCU]] = distinct !DICompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
|
2015-11-06 06:03:56 +08:00
|
|
|
; LW: ![[WSPs]] = !{![[WEAKFOOSP]]}
|
2015-08-29 04:26:49 +08:00
|
|
|
; LW: ![[WEAKFOOSP]] = distinct !DISubprogram(name: "foo",
|
2015-04-30 00:38:44 +08:00
|
|
|
; LW: ![[FOOINBAR]] = !DILocation(line: 2, scope: ![[FOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
|
|
|
|
|
; LW: ![[BARIA]] = !DILocation(line: 12, scope: ![[BARSP]])
|
|
|
|
|
; LW: ![[BARRET]] = !DILocation(line: 13, scope: ![[BARSP]])
|
|
|
|
|
; LW: ![[FOOCALL]] = !DILocation(line: 52, scope: ![[WEAKFOOSP]])
|
|
|
|
|
; LW: ![[FOORET]] = !DILocation(line: 53, scope: ![[WEAKFOOSP]])
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
|
|
|
|
|
; Same as above, but reordered.
|
2015-08-04 01:26:41 +08:00
|
|
|
; WL: ![[WCU]] = distinct !DICompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
|
2015-11-06 06:03:56 +08:00
|
|
|
; WL: ![[WSPs]] = !{![[WEAKFOOSP]]}
|
2015-08-29 04:26:49 +08:00
|
|
|
; WL: ![[WEAKFOOSP]] = distinct !DISubprogram(name: "foo",
|
2015-08-04 01:26:41 +08:00
|
|
|
; WL: ![[LCU]] = distinct !DICompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; WL: ![[LSPs]] = !{![[BARSP:[0-9]+]], ![[FOOSP:[0-9]+]]}
|
2015-08-29 04:26:49 +08:00
|
|
|
; WL: ![[BARSP]] = distinct !DISubprogram(name: "bar",
|
|
|
|
|
; WL: ![[FOOSP]] = distinct !DISubprogram(name: "foo",
|
2015-04-30 00:38:44 +08:00
|
|
|
; WL: ![[FOOCALL]] = !DILocation(line: 52, scope: ![[WEAKFOOSP]])
|
|
|
|
|
; WL: ![[FOORET]] = !DILocation(line: 53, scope: ![[WEAKFOOSP]])
|
|
|
|
|
; WL: ![[FOOINBAR]] = !DILocation(line: 2, scope: ![[FOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
|
|
|
|
|
; WL: ![[BARIA]] = !DILocation(line: 12, scope: ![[BARSP]])
|
|
|
|
|
; WL: ![[BARRET]] = !DILocation(line: 13, scope: ![[BARSP]])
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
|
2015-08-04 01:26:41 +08:00
|
|
|
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, subprograms: !{!3, !4}, emissionKind: 1)
|
2015-04-30 00:38:44 +08:00
|
|
|
!2 = !DIFile(filename: "bar.c", directory: "/path/to/dir")
|
2015-11-06 06:03:56 +08:00
|
|
|
!3 = distinct !DISubprogram(file: !2, scope: !2, line: 11, name: "bar", type: !5)
|
|
|
|
|
!4 = distinct !DISubprogram(file: !2, scope: !2, line: 1, name: "foo", type: !5)
|
2015-04-30 00:38:44 +08:00
|
|
|
!5 = !DISubroutineType(types: !{})
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
|
|
|
|
|
; Crasher for llc.
|
|
|
|
|
; REQUIRES: object-emission
|
|
|
|
|
; RUN: %llc_dwarf -filetype=obj -O0 %t1 -o %t1.o
|
|
|
|
|
; RUN: llvm-dwarfdump %t1.o -debug-dump=all | FileCheck %s -check-prefix=DWLW -check-prefix=DW
|
|
|
|
|
; RUN: %llc_dwarf -filetype=obj -O0 %t2 -o %t2.o
|
|
|
|
|
; RUN: llvm-dwarfdump %t2.o -debug-dump=all | FileCheck %s -check-prefix=DWWL -check-prefix=DW
|
|
|
|
|
; Check that the debug info for the discarded linkonce version of @foo doesn't
|
|
|
|
|
; reference any code, and that the other subprograms look correct.
|
|
|
|
|
|
|
|
|
|
; DW-LABEL: .debug_info contents:
|
|
|
|
|
; DWLW: DW_TAG_compile_unit
|
|
|
|
|
; DWLW: DW_AT_name {{.*}}"bar.c"
|
|
|
|
|
; DWLW: DW_TAG_subprogram
|
|
|
|
|
; DWLW-NOT: DW_AT_low_pc
|
|
|
|
|
; DWLW-NOT: DW_AT_high_pc
|
|
|
|
|
; DWLW: DW_AT_name {{.*}}foo
|
2015-03-27 21:52:12 +08:00
|
|
|
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; DWLW: DW_AT_decl_line {{.*}}(1)
|
|
|
|
|
; DWLW: DW_TAG_subprogram
|
|
|
|
|
; DWLW: DW_AT_low_pc
|
|
|
|
|
; DWLW: DW_AT_high_pc
|
|
|
|
|
; DWLW: DW_AT_name {{.*}}bar
|
2015-03-27 21:52:12 +08:00
|
|
|
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; DWLW: DW_AT_decl_line {{.*}}(11)
|
|
|
|
|
|
|
|
|
|
; DWLW: DW_TAG_inlined_subroutine
|
|
|
|
|
; DWLW: DW_AT_abstract_origin
|
|
|
|
|
; DWLW: DW_TAG_compile_unit
|
|
|
|
|
; DWLW: DW_AT_name {{.*}}"foo.c"
|
|
|
|
|
; DWLW: DW_TAG_subprogram
|
|
|
|
|
; DWLW: DW_AT_low_pc
|
|
|
|
|
; DWLW: DW_AT_high_pc
|
|
|
|
|
; DWLW: DW_AT_name {{.*}}foo
|
2015-03-27 21:52:12 +08:00
|
|
|
; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}foo.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; DWLW: DW_AT_decl_line {{.*}}(51)
|
|
|
|
|
|
|
|
|
|
; The DWARF output is already symmetric (just reordered).
|
|
|
|
|
; DWWL: DW_TAG_compile_unit
|
|
|
|
|
; DWWL: DW_AT_name {{.*}}"foo.c"
|
|
|
|
|
; DWWL: DW_TAG_subprogram
|
|
|
|
|
; DWWL: DW_AT_low_pc
|
|
|
|
|
; DWWL: DW_AT_high_pc
|
|
|
|
|
; DWWL: DW_AT_name {{.*}}foo
|
2015-03-27 21:52:12 +08:00
|
|
|
; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}foo.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
|
|
|
; DWWL: DW_AT_decl_line {{.*}}(51)
|
|
|
|
|
; DWWL: DW_TAG_compile_unit
|
|
|
|
|
; DWWL: DW_AT_name {{.*}}"bar.c"
|
|
|
|
|
; DWWL: DW_TAG_subprogram
|
|
|
|
|
; DWWL-NOT: DW_AT_low_pc
|
|
|
|
|
; DWWL-NOT: DW_AT_high_pc
|
|
|
|
|
; DWWL: DW_AT_name {{.*}}foo
|
2015-03-27 21:52:12 +08:00
|
|
|
; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
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; DWWL: DW_AT_decl_line {{.*}}(1)
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; DWWL: DW_TAG_subprogram
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; DWWL: DW_AT_low_pc
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; DWWL: DW_AT_high_pc
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; DWWL: DW_AT_name {{.*}}bar
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2015-03-27 21:52:12 +08:00
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; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir{{/|\\}}bar.c"
|
Reapply "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233254, effectively reapplying r233164 (and its
successors), with an additional testcase for when subprograms match
exactly. This fixes PR22792 (again).
I'm using the same approach, but I've moved up the call to
`stripReplacedSubprograms()`. The function pointers need to be dropped
before mapping any metadata from the source module, or else this can
drop the function from new subprograms that have merged (via Metadata
uniquing) with the old ones. Dropping the pointers first prevents them
from merging.
**** The original commit message follows. ****
Linker: Drop function pointers for overridden subprograms
Instead of dropping subprograms that have been overridden, just set
their function pointers to `nullptr`. This is a minor adjustment to the
stop-gap fix for PR21910 committed in r224487, and fixes the crasher
from PR22792.
The problem that r224487 put a band-aid on: how do we find the canonical
subprogram for a `Function`? Since the backend currently relies on
`DebugInfoFinder` (which does a naive in-order traversal of compile
units and picks the first subprogram) for this, r224487 tried dropping
non-canonical subprograms.
Dropping subprograms fails because the backend *also* builds up a map
from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
subprogram lists. A missing subprogram causes segfaults later when an
inlined reference (such as in this testcase) is created.
Instead, just drop the `Function` pointer to `nullptr`, which nicely
mirrors what happens when an already-inlined `Function` is optimized
out. We can't really be sure that it's the same definition anyway, as
the testcase demonstrates.
This still isn't completely satisfactory. Two flaws at least that I can
think of:
- I still haven't found a straightforward way to make this symmetric
in the IR. (Interestingly, the DWARF output is already symmetric,
and I've tested for that to be sure we don't regress.)
- Using `DebugInfoFinder` to find the canonical subprogram for a
function is kind of crazy. We should just attach metadata to the
function, like this:
define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
llvm-svn: 233302
2015-03-27 02:35:30 +08:00
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; DWWL: DW_AT_decl_line {{.*}}(11)
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; DWWL: DW_TAG_inlined_subroutine
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; DWWL: DW_AT_abstract_origin
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; DW-LABEL: .debug_line contents:
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; Check that we have the right things in the line table as well.
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; DWLW-LABEL: file_names[{{ *}}1]{{.*}} bar.c
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; DWLW: 2 0 1 0 0 is_stmt prologue_end
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; DWLW-LABEL: file_names[{{ *}}1]{{.*}} foo.c
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; DWLW: 52 0 1 0 0 is_stmt prologue_end
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; DWLW-NOT: prologue_end
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; DWWL-LABEL: file_names[{{ *}}1]{{.*}} foo.c
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; DWWL: 52 0 1 0 0 is_stmt prologue_end
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; DWWL-LABEL: file_names[{{ *}}1]{{.*}} bar.c
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; DWWL: 2 0 1 0 0 is_stmt prologue_end
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; DWWL-NOT: prologue_end
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