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Dave Bartolomeo
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C++: Generate IR side effects for smart pointer indirections
When inserting side effect instructions for argument indirections, we now insert side effects for smart pointers as we would for raw pointers. The address operand of the side effect instruction is the smart pointer object, which is a bit odd. However, I'd like to think through the design of a more principled solution before doing additional work. A few new tests are added to the existing IR tests. In addition, the IR tests now `#include` some of the shared STL headers. I've disabled IR dumps for functions from those headers, since they only get in the way of the test cases we intended.
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‎cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/SideEffects.qll‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,6 +7,7 @@
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88
private import cpp
99
private import semmle.code.cpp.ir.implementation.Opcode
10+
private import semmle.code.cpp.models.interfaces.PointerWrapper
1011
private import semmle.code.cpp.models.interfaces.SideEffect
1112

1213
/**
@@ -39,7 +40,8 @@ private predicate hasDefaultSideEffect(Call call, ParameterIndex i, boolean buff
3940
exists(Type t | t = expr.getUnspecifiedType() |
4041
t instanceof ArrayType or
4142
t instanceof PointerType or
42-
t instanceof ReferenceType
43+
t instanceof ReferenceType or
44+
t instanceof PointerWrapper
4345
) and
4446
(
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isWrite = true and

‎cpp/ql/test/library-tests/ir/ir/PrintAST.expected‎

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@@ -11365,6 +11365,86 @@ perf-regression.cpp:
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# 12| Type = [IntType] int
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# 12| Value = [Literal] 0
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# 12| ValueCategory = prvalue
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smart_ptr.cpp:
11369+
# 8| [TopLevelFunction] void unique_ptr_arg(std::unique_ptr<int, std::default_delete<int>>)
11370+
# 8| <params>:
11371+
# 8| getParameter(0): [Parameter] up
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# 8| Type = [ClassTemplateInstantiation] unique_ptr<int, default_delete<int>>
11373+
# 10| [TopLevelFunction] void call_unique_ptr_arg(int*)
11374+
# 10| <params>:
11375+
# 10| getParameter(0): [Parameter] p
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# 10| Type = [IntPointerType] int *
11377+
# 10| getEntryPoint(): [BlockStmt] { ... }
11378+
# 11| getStmt(0): [DeclStmt] declaration
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# 11| getDeclarationEntry(0): [VariableDeclarationEntry] definition of up
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# 11| Type = [ClassTemplateInstantiation] unique_ptr<int, default_delete<int>>
11381+
# 11| getVariable().getInitializer(): [Initializer] initializer for up
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# 11| getExpr(): [ConstructorCall] call to unique_ptr
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# 11| Type = [VoidType] void
11384+
# 11| ValueCategory = prvalue
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# 11| getArgument(0): [VariableAccess] p
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# 11| Type = [IntPointerType] int *
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# 11| ValueCategory = prvalue(load)
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# 12| getStmt(1): [ExprStmt] ExprStmt
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# 12| getExpr(): [FunctionCall] call to unique_ptr_arg
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# 12| Type = [VoidType] void
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# 12| ValueCategory = prvalue
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# 12| getArgument(0): [FunctionCall] call to move
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# 12| Type = [RValueReferenceType] type &&
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# 12| ValueCategory = prvalue
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# 12| getArgument(0): [VariableAccess] up
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# 12| Type = [ClassTemplateInstantiation] unique_ptr<int, default_delete<int>>
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# 12| ValueCategory = lvalue
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# 12| getArgument(0).getFullyConverted(): [ReferenceToExpr] (reference to)
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# 12| Type = [LValueReferenceType] unique_ptr<int, default_delete<int>> &
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# 12| ValueCategory = prvalue
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# 12| getArgument(0).getFullyConverted(): [TemporaryObjectExpr] temporary object
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# 12| Type = [ClassTemplateInstantiation] unique_ptr<int, default_delete<int>>
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# 12| ValueCategory = lvalue
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# 12| getExpr(): [ReferenceDereferenceExpr] (reference dereference)
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# 12| Type = [CTypedefType,NestedTypedefType] type
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# 12| ValueCategory = prvalue(load)
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# 13| getStmt(2): [ReturnStmt] return ...
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# 15| [TopLevelFunction] void shared_ptr_arg(std::shared_ptr<float>)
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# 15| <params>:
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# 15| getParameter(0): [Parameter] sp
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# 15| Type = [ClassTemplateInstantiation] shared_ptr<float>
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# 17| [TopLevelFunction] void call_shared_ptr_arg(float*)
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# 17| <params>:
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# 17| getParameter(0): [Parameter] p
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# 17| Type = [PointerType] float *
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# 17| getEntryPoint(): [BlockStmt] { ... }
11417+
# 18| getStmt(0): [DeclStmt] declaration
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# 18| getDeclarationEntry(0): [VariableDeclarationEntry] definition of sp
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# 18| Type = [ClassTemplateInstantiation] shared_ptr<float>
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# 18| getVariable().getInitializer(): [Initializer] initializer for sp
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# 18| getExpr(): [ConstructorCall] call to shared_ptr
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# 18| Type = [VoidType] void
11423+
# 18| ValueCategory = prvalue
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# 18| getArgument(0): [VariableAccess] p
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# 18| Type = [PointerType] float *
11426+
# 18| ValueCategory = prvalue(load)
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# 19| getStmt(1): [ExprStmt] ExprStmt
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# 19| getExpr(): [FunctionCall] call to shared_ptr_arg
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# 19| Type = [VoidType] void
11430+
# 19| ValueCategory = prvalue
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# 19| getArgument(0): [ConstructorCall] call to shared_ptr
11432+
# 19| Type = [VoidType] void
11433+
# 19| ValueCategory = prvalue
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# 19| getArgument(0): [VariableAccess] sp
11435+
# 19| Type = [ClassTemplateInstantiation] shared_ptr<float>
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# 19| ValueCategory = lvalue
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# 19| getArgument(0).getFullyConverted(): [ReferenceToExpr] (reference to)
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# 19| Type = [LValueReferenceType] const shared_ptr<float> &
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# 19| ValueCategory = prvalue
11440+
# 19| getExpr(): [CStyleCast] (const shared_ptr<float>)...
11441+
# 19| Conversion = [GlvalueConversion] glvalue conversion
11442+
# 19| Type = [SpecifiedType] const shared_ptr<float>
11443+
# 19| ValueCategory = lvalue
11444+
# 19| getArgument(0).getFullyConverted(): [TemporaryObjectExpr] temporary object
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# 19| Type = [ClassTemplateInstantiation] shared_ptr<float>
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# 19| ValueCategory = lvalue
11447+
# 20| getStmt(2): [ReturnStmt] return ...
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struct_init.cpp:
1136911449
# 1| [TopLevelFunction] int handler1(void*)
1137011450
# 1| <params>:

‎cpp/ql/test/library-tests/ir/ir/PrintAST.ql‎

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
/**
2+
* @kind graph
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*/
4+
5+
private import cpp
6+
private import semmle.code.cpp.PrintAST
7+
private import PrintConfig
8+
9+
private class PrintConfig extends PrintASTConfiguration {
10+
override predicate shouldPrintFunction(Function func) { shouldDumpFunction(func) }
11+
}

‎cpp/ql/test/library-tests/ir/ir/PrintAST.qlref‎

Lines changed: 0 additions & 1 deletion
This file was deleted.

‎cpp/ql/test/library-tests/ir/ir/PrintConfig.qll‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,10 @@
1+
private import cpp
2+
3+
/**
4+
* Holds if the AST or IR for the specified function should be printed in the test output.
5+
*
6+
* This predicate excludes functions defined in standard headers.
7+
*/
8+
predicate shouldDumpFunction(Function func) {
9+
not func.getLocation().getFile().getAbsolutePath().regexpMatch(".*/include/[^/]+")
10+
}

‎cpp/ql/test/library-tests/ir/ir/raw_consistency.expected‎

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Original file line numberDiff line numberDiff line change
@@ -6,6 +6,7 @@ missingOperandType
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duplicateChiOperand
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sideEffectWithoutPrimary
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instructionWithoutSuccessor
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| ../../../include/memory.h:68:25:68:33 | CopyValue: (reference to) | Instruction 'CopyValue: (reference to)' has no successors in function '$@'. | ../../../include/memory.h:67:5:67:5 | void std::unique_ptr<int, std::default_delete<int>>::~unique_ptr() | void std::unique_ptr<int, std::default_delete<int>>::~unique_ptr() |
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ambiguousSuccessors
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unexplainedLoop
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unnecessaryPhiInstruction

‎cpp/ql/test/library-tests/ir/ir/raw_ir.expected‎

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Original file line numberDiff line numberDiff line change
@@ -7903,6 +7903,80 @@ perf-regression.cpp:
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# 9| v9_6(void) = AliasedUse : ~m?
79047904
# 9| v9_7(void) = ExitFunction :
79057905

7906+
smart_ptr.cpp:
7907+
# 10| void call_unique_ptr_arg(int*)
7908+
# 10| Block 0
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# 10| v10_1(void) = EnterFunction :
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# 10| mu10_2(unknown) = AliasedDefinition :
7911+
# 10| mu10_3(unknown) = InitializeNonLocal :
7912+
# 10| r10_4(glval<int *>) = VariableAddress[p] :
7913+
# 10| mu10_5(int *) = InitializeParameter[p] : &:r10_4
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# 10| r10_6(int *) = Load[p] : &:r10_4, ~m?
7915+
# 10| mu10_7(unknown) = InitializeIndirection[p] : &:r10_6
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# 11| r11_1(glval<unique_ptr<int, default_delete<int>>>) = VariableAddress[up] :
7917+
# 11| mu11_2(unique_ptr<int, default_delete<int>>) = Uninitialized[up] : &:r11_1
7918+
# 11| r11_3(glval<unknown>) = FunctionAddress[unique_ptr] :
7919+
# 11| r11_4(glval<int *>) = VariableAddress[p] :
7920+
# 11| r11_5(int *) = Load[p] : &:r11_4, ~m?
7921+
# 11| v11_6(void) = Call[unique_ptr] : func:r11_3, this:r11_1, 0:r11_5
7922+
# 11| mu11_7(unknown) = ^CallSideEffect : ~m?
7923+
# 11| mu11_8(unique_ptr<int, default_delete<int>>) = ^IndirectMustWriteSideEffect[-1] : &:r11_1
7924+
# 12| r12_1(glval<unknown>) = FunctionAddress[unique_ptr_arg] :
7925+
# 12| r12_2(glval<unique_ptr<int, default_delete<int>>>) = VariableAddress[#temp12:20] :
7926+
# 12| r12_3(glval<unknown>) = FunctionAddress[move] :
7927+
# 12| r12_4(glval<unique_ptr<int, default_delete<int>>>) = VariableAddress[up] :
7928+
# 12| r12_5(unique_ptr<int, default_delete<int>> &) = CopyValue : r12_4
7929+
# 12| r12_6(unique_ptr<int, default_delete<int>> &&) = Call[move] : func:r12_3, 0:r12_5
7930+
# 12| r12_7(unique_ptr<int, default_delete<int>>) = Load[?] : &:r12_6, ~m?
7931+
# 12| mu12_8(unique_ptr<int, default_delete<int>>) = Store[#temp12:20] : &:r12_2, r12_7
7932+
# 12| r12_9(unique_ptr<int, default_delete<int>>) = Load[#temp12:20] : &:r12_2, ~m?
7933+
# 12| v12_10(void) = Call[unique_ptr_arg] : func:r12_1, 0:r12_9
7934+
# 12| mu12_11(unknown) = ^CallSideEffect : ~m?
7935+
# 12| v12_12(void) = ^BufferReadSideEffect[0] : &:r12_9, ~m?
7936+
# 13| v13_1(void) = NoOp :
7937+
# 10| v10_8(void) = ReturnIndirection[p] : &:r10_6, ~m?
7938+
# 10| v10_9(void) = ReturnVoid :
7939+
# 10| v10_10(void) = AliasedUse : ~m?
7940+
# 10| v10_11(void) = ExitFunction :
7941+
7942+
# 17| void call_shared_ptr_arg(float*)
7943+
# 17| Block 0
7944+
# 17| v17_1(void) = EnterFunction :
7945+
# 17| mu17_2(unknown) = AliasedDefinition :
7946+
# 17| mu17_3(unknown) = InitializeNonLocal :
7947+
# 17| r17_4(glval<float *>) = VariableAddress[p] :
7948+
# 17| mu17_5(float *) = InitializeParameter[p] : &:r17_4
7949+
# 17| r17_6(float *) = Load[p] : &:r17_4, ~m?
7950+
# 17| mu17_7(unknown) = InitializeIndirection[p] : &:r17_6
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# 18| r18_1(glval<shared_ptr<float>>) = VariableAddress[sp] :
7952+
# 18| mu18_2(shared_ptr<float>) = Uninitialized[sp] : &:r18_1
7953+
# 18| r18_3(glval<unknown>) = FunctionAddress[shared_ptr] :
7954+
# 18| r18_4(glval<float *>) = VariableAddress[p] :
7955+
# 18| r18_5(float *) = Load[p] : &:r18_4, ~m?
7956+
# 18| v18_6(void) = Call[shared_ptr] : func:r18_3, this:r18_1, 0:r18_5
7957+
# 18| mu18_7(unknown) = ^CallSideEffect : ~m?
7958+
# 18| mu18_8(shared_ptr<float>) = ^IndirectMustWriteSideEffect[-1] : &:r18_1
7959+
# 19| r19_1(glval<unknown>) = FunctionAddress[shared_ptr_arg] :
7960+
# 19| r19_2(glval<shared_ptr<float>>) = VariableAddress[#temp19:20] :
7961+
# 19| mu19_3(shared_ptr<float>) = Uninitialized[#temp19:20] : &:r19_2
7962+
# 19| r19_4(glval<unknown>) = FunctionAddress[shared_ptr] :
7963+
# 19| r19_5(glval<shared_ptr<float>>) = VariableAddress[sp] :
7964+
# 19| r19_6(glval<shared_ptr<float>>) = Convert : r19_5
7965+
# 19| r19_7(shared_ptr<float> &) = CopyValue : r19_6
7966+
# 19| v19_8(void) = Call[shared_ptr] : func:r19_4, this:r19_2, 0:r19_7
7967+
# 19| mu19_9(unknown) = ^CallSideEffect : ~m?
7968+
# 19| mu19_10(shared_ptr<float>) = ^IndirectMustWriteSideEffect[-1] : &:r19_2
7969+
# 19| v19_11(void) = ^IndirectReadSideEffect[0] : &:r19_7, ~m?
7970+
# 19| r19_12(shared_ptr<float>) = Load[#temp19:20] : &:r19_2, ~m?
7971+
# 19| v19_13(void) = Call[shared_ptr_arg] : func:r19_1, 0:r19_12
7972+
# 19| mu19_14(unknown) = ^CallSideEffect : ~m?
7973+
# 19| v19_15(void) = ^BufferReadSideEffect[0] : &:r19_12, ~m?
7974+
# 20| v20_1(void) = NoOp :
7975+
# 17| v17_8(void) = ReturnIndirection[p] : &:r17_6, ~m?
7976+
# 17| v17_9(void) = ReturnVoid :
7977+
# 17| v17_10(void) = AliasedUse : ~m?
7978+
# 17| v17_11(void) = ExitFunction :
7979+
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struct_init.cpp:
79077981
# 16| void let_info_escape(Info*)
79087982
# 16| Block 0

‎cpp/ql/test/library-tests/ir/ir/raw_ir.ql‎

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/**
2+
* @kind graph
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*/
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5+
private import cpp
6+
private import semmle.code.cpp.ir.implementation.raw.PrintIR
7+
private import PrintConfig
8+
9+
private class PrintConfig extends PrintIRConfiguration {
10+
override predicate shouldPrintFunction(Function func) { shouldDumpFunction(func) }
11+
}

‎cpp/ql/test/library-tests/ir/ir/raw_ir.qlref‎

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This file was deleted.

‎cpp/ql/test/library-tests/ir/ir/smart_ptr.cpp‎

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#include "../../../include/memory.h"
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#include "../../../include/utility.h"
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4+
using std::move;
5+
using std::shared_ptr;
6+
using std::unique_ptr;
7+
8+
void unique_ptr_arg(unique_ptr<int> up);
9+
10+
void call_unique_ptr_arg(int* p) {
11+
unique_ptr<int> up(p);
12+
unique_ptr_arg(move(up));
13+
}
14+
15+
void shared_ptr_arg(shared_ptr<float> sp);
16+
17+
void call_shared_ptr_arg(float* p) {
18+
shared_ptr<float> sp(p);
19+
shared_ptr_arg(sp);
20+
}

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