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Fix issue 22298 - Nested function's scope parameters can be assigned to variables in enclosing function #13530

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Merged
dlang-bot merged 1 commit into from
Jan 14, 2022
Merged

Fix issue 22298 - Nested function's scope parameters can be assigned to variables in enclosing function #13530

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2 changes: 0 additions & 2 deletions src/dmd/astbase.d
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Original file line number Diff line number Diff line change
Expand Up @@ -481,7 +481,6 @@ struct ASTBase
enum AdrOnStackNone = ~0u;
uint ctfeAdrOnStack;
uint sequenceNumber;
__gshared uint nextSequenceNumber;

final extern (D) this(const ref Loc loc, Type type, Identifier id, Initializer _init, StorageClass st = STC.undefined_)
{
Expand All @@ -490,7 +489,6 @@ struct ASTBase
this._init = _init;
this.loc = loc;
this.storage_class = st;
sequenceNumber = ++nextSequenceNumber;
ctfeAdrOnStack = AdrOnStackNone;
}

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10 changes: 3 additions & 7 deletions src/dmd/declaration.d
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Expand Up @@ -1048,7 +1048,6 @@ extern (C++) class VarDeclaration : Declaration
uint endlinnum; // line number of end of scope that this var lives in
uint offset;
uint sequenceNumber; // order the variables are declared
__gshared uint nextSequenceNumber; // the counter for sequenceNumber
structalign_t alignment;

// When interpreting, these point to the value (NULL if value not determinable)
Expand Down Expand Up @@ -1099,7 +1098,6 @@ extern (C++) class VarDeclaration : Declaration
this._init = _init;
ctfeAdrOnStack = AdrOnStackNone;
this.storage_class = storage_class;
sequenceNumber = ++nextSequenceNumber;
}

static VarDeclaration create(const ref Loc loc, Type type, Identifier ident, Initializer _init, StorageClass storage_class = STC.undefined_)
Expand Down Expand Up @@ -1657,12 +1655,10 @@ extern (C++) class VarDeclaration : Declaration
// Sequence numbers work when there are no special VarDeclaration's involved
if (!((this.storage_class | v.storage_class) & special))
{
// FIXME: VarDeclaration's for parameters are created in semantic3, so
// they will have a greater sequence number than local variables.
// Hence reverse the result for mixed comparisons.
const exp = this.isParameter() == v.isParameter();
assert(this.sequenceNumber != this.sequenceNumber.init);
assert(v.sequenceNumber != v.sequenceNumber.init);

return (this.sequenceNumber < v.sequenceNumber) == exp;
return (this.sequenceNumber < v.sequenceNumber);
}

// Assume that semantic produces temporaries according to their lifetime
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2 changes: 2 additions & 0 deletions src/dmd/dsymbolsem.d
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Expand Up @@ -356,6 +356,8 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
if (sc && sc.inunion && sc.inunion.isAnonDeclaration())
dsym.overlapped = true;

dsym.sequenceNumber = global.varSequenceNumber++;

Scope* scx = null;
if (dsym._scope)
{
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4 changes: 2 additions & 2 deletions src/dmd/escape.d
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Expand Up @@ -691,8 +691,8 @@ bool checkAssignEscape(Scope* sc, Expression e, bool gag)
}

// If va's lifetime encloses v's, then error
if (va &&
(va.enclosesLifetimeOf(v) && !(v.storage_class & (STC.parameter | STC.temp)) ||
if (va && !va.isDataseg() &&
(va.enclosesLifetimeOf(v) && !(v.storage_class & STC.temp) ||
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@MoonlightSentinel MoonlightSentinel Jan 14, 2022

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Is the check for STC.temp still necessary?

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@dkorpel dkorpel Jan 14, 2022

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Maybe not, let's see what the test suite says.

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@dkorpel dkorpel Jan 14, 2022 •
edited
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std/datetime/systime.d(9085): Error: scope variable `__tup794` assigned to `foundTZ` with longer lifetime

Looks like it's still needed for tuple lowering.

// va is class reference
ae.e1.isDotVarExp() && va.type.toBasetype().isTypeClass() && (va.enclosesLifetimeOf(v) ||
!va.isScope()) ||
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10 changes: 6 additions & 4 deletions src/dmd/frontend.h
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Expand Up @@ -857,6 +857,7 @@ struct Global final
Array<Identifier* >* versionids;
Array<Identifier* >* debugids;
bool hasMainFunction;
uint32_t varSequenceNumber;
enum : int32_t { recursionLimit = 500 };

uint32_t startGagging();
Expand All @@ -881,10 +882,11 @@ struct Global final
console(),
versionids(),
debugids(),
hasMainFunction()
hasMainFunction(),
varSequenceNumber(1u)
{
}
Global(_d_dynamicArray< const char > inifilename, _d_dynamicArray< const char > copyright = { 73, "Copyright (C) 1999-2022 by The D Language Foundation, All Rights Reserved" }, _d_dynamicArray< const char > written = { 24, "written by Walter Bright" }, Array<const char* >* path = nullptr, Array<const char* >* filePath = nullptr, _d_dynamicArray< const char > vendor = {}, Param params = Param(true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, false, 0u, false, false, (DiagnosticReporting)1u, false, false, false, (FeatureState)-1, (FeatureState)-1, false, false, false, (DiagnosticReporting)2u, (PIC)0u, false, false, 0u, false, false, false, true, true, true, false, false, false, false, false, false, true, false, false, false, (FeatureState)-1, false, false, (CppStdRevision)201103u, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKACTION)0u, 20u, {}, Array<const char* >(0LLU, {}, arrayliteral), nullptr, nullptr, {}, {}, {}, false, {}, {}, Array<const char* >(0LLU, {}, arrayliteral), false, {}, {}, true, (CxxHeaderMode)0u, {}, {}, false, {}, (JsonFieldFlags)0u, nullptr, nullptr, 0, 0u, nullptr, 0u, nullptr, {}, {}, {}, {}, nullptr, false, {}, Array<const char* >(0LLU, {}, arrayliteral), (MessageStyle)0u, false, Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<bool >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), {}, {}, {}, {}), uint32_t errors = 0u, uint32_t warnings = 0u, uint32_t gag = 0u, uint32_t gaggedErrors = 0u, uint32_t gaggedWarnings = 0u, void* console = nullptr, Array<Identifier* >* versionids = nullptr, Array<Identifier* >* debugids = nullptr, bool hasMainFunction = false) :
Global(_d_dynamicArray< const char > inifilename, _d_dynamicArray< const char > copyright = { 73, "Copyright (C) 1999-2022 by The D Language Foundation, All Rights Reserved" }, _d_dynamicArray< const char > written = { 24, "written by Walter Bright" }, Array<const char* >* path = nullptr, Array<const char* >* filePath = nullptr, _d_dynamicArray< const char > vendor = {}, Param params = Param(true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, false, 0u, false, false, (DiagnosticReporting)1u, false, false, false, (FeatureState)-1, (FeatureState)-1, false, false, false, (DiagnosticReporting)2u, (PIC)0u, false, false, 0u, false, false, false, true, true, true, false, false, false, false, false, false, true, false, false, false, (FeatureState)-1, false, false, (CppStdRevision)201103u, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKENABLE)0u, (CHECKACTION)0u, 20u, {}, Array<const char* >(0LLU, {}, arrayliteral), nullptr, nullptr, {}, {}, {}, false, {}, {}, Array<const char* >(0LLU, {}, arrayliteral), false, {}, {}, true, (CxxHeaderMode)0u, {}, {}, false, {}, (JsonFieldFlags)0u, nullptr, nullptr, 0, 0u, nullptr, 0u, nullptr, {}, {}, {}, {}, nullptr, false, {}, Array<const char* >(0LLU, {}, arrayliteral), (MessageStyle)0u, false, Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<bool >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), Array<const char* >(0LLU, {}, arrayliteral), {}, {}, {}, {}), uint32_t errors = 0u, uint32_t warnings = 0u, uint32_t gag = 0u, uint32_t gaggedErrors = 0u, uint32_t gaggedWarnings = 0u, void* console = nullptr, Array<Identifier* >* versionids = nullptr, Array<Identifier* >* debugids = nullptr, bool hasMainFunction = false, uint32_t varSequenceNumber = 1u) :
inifilename(inifilename),
copyright(copyright),
written(written),
Expand All @@ -900,7 +902,8 @@ struct Global final
console(console),
versionids(versionids),
debugids(debugids),
hasMainFunction(hasMainFunction)
hasMainFunction(hasMainFunction),
varSequenceNumber(varSequenceNumber)
{}
};

Expand Down Expand Up @@ -5772,7 +5775,6 @@ class VarDeclaration : public Declaration
uint32_t endlinnum;
uint32_t offset;
uint32_t sequenceNumber;
static uint32_t nextSequenceNumber;
structalign_t alignment;
enum : uint32_t { AdrOnStackNone = 4294967295u };

Expand Down
1 change: 1 addition & 0 deletions src/dmd/globals.d
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Expand Up @@ -327,6 +327,7 @@ extern (C++) struct Global
Array!Identifier* debugids; /// command line debug versions and predefined versions

bool hasMainFunction; /// Whether a main function has already been compiled in (for -main switch)
uint varSequenceNumber = 1; /// Relative lifetime of `VarDeclaration` within a function, used for `scope` checks

enum recursionLimit = 500; /// number of recursive template expansions before abort

Expand Down
1 change: 1 addition & 0 deletions src/dmd/globals.h
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Expand Up @@ -290,6 +290,7 @@ struct Global
Array<class Identifier*>* debugids; // command line debug versions and predefined versions

bool hasMainFunction;
unsigned varSequenceNumber;

/* Start gagging. Return the current number of gagged errors
*/
Expand Down
30 changes: 30 additions & 0 deletions test/fail_compilation/test22298.d
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@@ -0,0 +1,30 @@
/*
REQUIRED_ARGS: -preview=dip1000
TEST_OUTPUT:
---
fail_compilation/test22298.d(18): Error: scope variable `i` assigned to `p` with longer lifetime
fail_compilation/test22298.d(29): Error: scope variable `y` assigned to `x` with longer lifetime
---
*/

void g(scope void delegate(scope int*) @safe cb) @safe {
int x = 42;
cb(&x);
}

void main() @safe {
int* p;
void f(scope int* i) @safe {
p = i;
}

g(&f);
// address of x has escaped g
assert(*p == 42);
}

void f() @safe {
mixin("scope int* x;");
scope int* y;
x = y;
}