llvm-project/llvm/test/DebugInfo/Generic/cross-cu-linkonce-distinct.ll

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; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -v -debug-info - | FileCheck %s
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
; Testing that two distinct (distinct by writing them in separate files, while
; still fulfilling C++'s ODR by having identical token sequences) functions,
; linked under LTO, get plausible debug info (and don't crash).
; Built from source:
; $ clang++ a.cpp b.cpp -g -c -emit-llvm
; $ llvm-link a.bc b.bc -o ab.bc
; This change is intended to tickle a case where the subprogram MDNode
; associated with the llvm::Function will differ from the subprogram
; referenced by the DbgLocs in the function.
; $ sed -ie "s/!12, !0/!0, !12/" ab.ll
; $ cat a.cpp
; inline int func(int i) {
; return i * 2;
; }
; int (*x)(int) = &func;
; $ cat b.cpp
; inline int func(int i) {
; return i * 2;
; }
; int (*y)(int) = &func;
; The DISubprogram should show up in compile unit a.
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
; CHECK: DW_TAG_compile_unit
; CHECK-NOT: DW_TAG
; CHECK: DW_AT_name {{.*}}"b.cpp"
; CHECK-NOT: DW_TAG_subprogram
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
; CHECK: DW_TAG_compile_unit
; CHECK-NOT: DW_TAG
; CHECK: DW_AT_name {{.*}}"a.cpp"
; CHECK: DW_AT_name {{.*}} "func"
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
source_filename = "test/DebugInfo/Generic/cross-cu-linkonce-distinct.ll"
@x = global i32 (i32)* @_Z4funci, align 8, !dbg !0
@y = global i32 (i32)* @_Z4funci, align 8, !dbg !7
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
; Function Attrs: inlinehint nounwind uwtable
define linkonce_odr i32 @_Z4funci(i32 %i) #0 !dbg !18 {
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
%1 = alloca i32, align 4
store i32 %i, i32* %1, align 4
call void @llvm.dbg.declare(metadata i32* %1, metadata !19, metadata !20), !dbg !21
%2 = load i32, i32* %1, align 4, !dbg !22
%3 = mul nsw i32 %2, 2, !dbg !22
ret i32 %3, !dbg !22
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
}
; Function Attrs: nounwind readnone
Move the complex address expression out of DIVariable and into an extra argument of the llvm.dbg.declare/llvm.dbg.value intrinsics. Previously, DIVariable was a variable-length field that has an optional reference to a Metadata array consisting of a variable number of complex address expressions. In the case of OpPiece expressions this is wasting a lot of storage in IR, because when an aggregate type is, e.g., SROA'd into all of its n individual members, the IR will contain n copies of the DIVariable, all alike, only differing in the complex address reference at the end. By making the complex address into an extra argument of the dbg.value/dbg.declare intrinsics, all of the pieces can reference the same variable and the complex address expressions can be uniqued across the CU, too. Down the road, this will allow us to move other flags, such as "indirection" out of the DIVariable, too. The new intrinsics look like this: declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr) declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr) This patch adds a new LLVM-local tag to DIExpressions, so we can detect and pretty-print DIExpression metadata nodes. What this patch doesn't do: This patch does not touch the "Indirect" field in DIVariable; but moving that into the expression would be a natural next step. http://reviews.llvm.org/D4919 rdar://problem/17994491 Thanks to dblaikie and dexonsmith for reviewing this patch! Note: I accidentally committed a bogus older version of this patch previously. llvm-svn: 218787
2014-10-02 02:55:02 +08:00
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
attributes #0 = { inlinehint nounwind uwtable }
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00
attributes #1 = { nounwind readnone }
!llvm.dbg.cu = !{!10, !13}
!llvm.module.flags = !{!15, !16}
!llvm.ident = !{!17, !17}
!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
!1 = !DIGlobalVariable(name: "x", scope: null, file: !2, line: 4, type: !3, isLocal: false, isDefinition: true)
!2 = !DIFile(filename: "a.cpp", directory: "/tmp/dbginfo")
!3 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !4, size: 64, align: 64)
!4 = !DISubroutineType(types: !5)
!5 = !{!6, !6}
!6 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!7 = !DIGlobalVariableExpression(var: !8, expr: !DIExpression())
!8 = !DIGlobalVariable(name: "y", scope: null, file: !9, line: 4, type: !3, isLocal: false, isDefinition: true)
!9 = !DIFile(filename: "b.cpp", directory: "/tmp/dbginfo")
!10 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !9, producer: "clang version 3.5.0 ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !11, retainedTypes: !11, globals: !12, imports: !11)
!11 = !{}
!12 = !{!7}
!13 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, producer: "clang version 3.5.0 ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !11, retainedTypes: !11, globals: !14, imports: !11)
!14 = !{!0}
!15 = !{i32 2, !"Dwarf Version", i32 4}
!16 = !{i32 1, !"Debug Info Version", i32 3}
!17 = !{!"clang version 3.5.0 "}
!18 = distinct !DISubprogram(name: "func", linkageName: "_Z4funci", scope: !2, file: !2, line: 1, type: !4, isLocal: false, isDefinition: true, scopeLine: 1, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !13, retainedNodes: !11)
!19 = !DILocalVariable(name: "i", arg: 1, scope: !18, file: !2, line: 1, type: !6)
!20 = !DIExpression()
!21 = !DILocation(line: 1, scope: !18)
!22 = !DILocation(line: 2, scope: !18)
Recommit r212203: Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information. Reverted by Eric Christopher (Thanks!) in r212203 after Bob Wilson reported LTO issues. Duncan Exon Smith and Aditya Nandakumar helped provide a reduced reproduction, though the failure wasn't too hard to guess, and even easier with the example to confirm. The assertion that the subprogram metadata associated with an llvm::Function matches the scope data referenced by the DbgLocs on the instructions in that function is not valid under LTO. In LTO, a C++ inline function might exist in multiple CUs and the subprogram metadata nodes will refer to the same llvm::Function. In this case, depending on the order of the CUs, the first intance of the subprogram metadata may not be the one referenced by the instructions in that function and the assertion will fail. A test case (test/DebugInfo/cross-cu-linkonce-distinct.ll) is added, the assertion removed and a comment added to explain this situation. This was then reverted again in r213581 as it caused PR20367. The root cause of this was the early exit in LiveDebugVariables meant that spurious DBG_VALUE intrinsics that referenced dead variables were not removed, causing an assertion/crash later on. The fix is to have LiveDebugVariables strip all DBG_VALUE intrinsics in functions without debug info as they're not needed anyway. Test case added to cover this situation (that occurs when a debug-having function is inlined into a nodebug function) in test/DebugInfo/X86/nodebug_with_debug_loc.ll Original commit message: If a function isn't actually in a CU's subprogram list in the debug info metadata, ignore all the DebugLocs and don't try to build scopes, track variables, etc. While this is possibly a minor optimization, it's also a correctness fix for an incoming patch that will add assertions to LexicalScopes and the debug info verifier to ensure that all scope chains lead to debug info for the current function. Fix up a few test cases that had broken/incomplete debug info that could violate this constraint. Add a test case where this occurs by design (inlining a debug-info-having function in an attribute nodebug function - we want this to work because /if/ the nodebug function is then inlined into a debug-info-having function, it should be fine (and will work fine - we just stitch the scopes up as usual), but should the inlining not happen we need to not assert fail either). llvm-svn: 213952
2014-07-26 00:10:16 +08:00