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Destroy temporaries at the end of expression statements. (#7513)

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Instead of tracking the cleanup scope depth on entry to each scope,
track an "ambient" cleanup scope depth that's *after* the destructors of
local variables in that scope. This gets increased to include the
destructors of local variables when we create a name-binding
declaration. Then, when we reach a point where temporaries should be
destroyed, run cleanups that are after the ambient cleanup scope depth
on the stack. This happens:

* At the `;` of a statement expression.
* At the `)` of an `if` or `while` statement.
* After performing the implied `HasValue()` call in a `for` statement.

Per informal agreement with leads, this means we lifetime-extend all
temporaries created in the initializer of a name-binding declaration to
the full scope of that declaration, but that temporaries created in an
expression statement are destroyed at the `;`.
This commit is contained in:
Richard Smith
2026-07-16 15:12:39 +00:00
committed by GitHub
parent 81e495ee53
commit 703529fc55
37 changed files with 844 additions and 384 deletions
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toolchain/lower/testdata/function/definition/destroy.carbon
Vendored
+4 -8
View File
@@ -23,8 +23,6 @@ fn G();
fn CallF() {
F({});
// TODO: The `C` instance is destroyed after the call to `G()`, and
// should be destroyed before.
G();
}
@@ -41,8 +39,6 @@ fn G();
fn CallF() {
F({});
// TODO: The `C` instance is destroyed after the call to `G()`, and
// should be destroyed before.
G();
}
@@ -93,8 +89,8 @@ fn InitLet() {
// CHECK:STDOUT: %.loc12_6.2.temp = alloca {}, align 1, !dbg !14
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc12_6.2.temp), !dbg !14
// CHECK:STDOUT: call void @_CF.Main(ptr @C.val.loc12_6.6), !dbg !15
// CHECK:STDOUT: call void @_CG.Main(), !dbg !16
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr @C.val), !dbg !14
// CHECK:STDOUT: call void @_CG.Main(), !dbg !16
// CHECK:STDOUT: ret void, !dbg !17
// CHECK:STDOUT: }
// CHECK:STDOUT:
@@ -129,7 +125,7 @@ fn InitLet() {
// CHECK:STDOUT: !13 = !{null}
// CHECK:STDOUT: !14 = !DILocation(line: 12, column: 5, scope: !11)
// CHECK:STDOUT: !15 = !DILocation(line: 12, column: 3, scope: !11)
// CHECK:STDOUT: !16 = !DILocation(line: 15, column: 3, scope: !11)
// CHECK:STDOUT: !16 = !DILocation(line: 13, column: 3, scope: !11)
// CHECK:STDOUT: !17 = !DILocation(line: 11, column: 1, scope: !11)
// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "Op", linkageName: "_COp.807eb4f2d3ed7e54:core.Destroy.Core", scope: null, file: !1, line: 12, type: !5, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !19)
// CHECK:STDOUT: !19 = !{!20}
@@ -157,8 +153,8 @@ fn InitLet() {
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var), !dbg !14
// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %_.var, ptr align 1 @C.val.loc6, i64 0, i1 false), !dbg !14
// CHECK:STDOUT: call void @_CF.Main(ptr %_.var), !dbg !15
// CHECK:STDOUT: call void @_CG.Main(), !dbg !16
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr %_.var), !dbg !14
// CHECK:STDOUT: call void @_CG.Main(), !dbg !16
// CHECK:STDOUT: ret void, !dbg !17
// CHECK:STDOUT: }
// CHECK:STDOUT:
@@ -196,7 +192,7 @@ fn InitLet() {
// CHECK:STDOUT: !13 = !{null}
// CHECK:STDOUT: !14 = !DILocation(line: 6, column: 6, scope: !11)
// CHECK:STDOUT: !15 = !DILocation(line: 12, column: 3, scope: !11)
// CHECK:STDOUT: !16 = !DILocation(line: 15, column: 3, scope: !11)
// CHECK:STDOUT: !16 = !DILocation(line: 13, column: 3, scope: !11)
// CHECK:STDOUT: !17 = !DILocation(line: 11, column: 1, scope: !11)
// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "Op", linkageName: "_COp.807eb4f2d3ed7e54:core.Destroy.Core", scope: null, file: !1, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !19)
// CHECK:STDOUT: !19 = !{!20}
toolchain/lower/testdata/function/definition/var_param.carbon
Vendored
+22 -20
View File
@@ -24,6 +24,8 @@ fn Call() {
OneVar_i32(1);
OneVar_X({});
TwoVars(1, {});
// TODO: This passes a global as the `X` parameter, then destroys a different
// `X` global. We shouldn't be calling Destroy on a global.
VarThenLet(1, {});
LetThenVar(1, {});
}
@@ -73,44 +75,44 @@ fn Call() {
// CHECK:STDOUT: %_.var.loc18_12 = alloca i32, align 4, !dbg !40
// CHECK:STDOUT: %_.var.loc18_24 = alloca {}, align 1, !dbg !41
// CHECK:STDOUT: %_.var.loc20 = alloca i32, align 4, !dbg !42
// CHECK:STDOUT: %.loc27_18.2.temp = alloca {}, align 1, !dbg !43
// CHECK:STDOUT: %.loc29_18.2.temp = alloca {}, align 1, !dbg !43
// CHECK:STDOUT: %_.var.loc21 = alloca {}, align 1, !dbg !44
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc15), !dbg !38
// CHECK:STDOUT: store i32 1, ptr %_.var.loc15, align 4, !dbg !38
// CHECK:STDOUT: call void @_COneVar_i32.Main(ptr %_.var.loc15), !dbg !45
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc15), !dbg !38
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc16), !dbg !39
// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %_.var.loc16, ptr align 1 @X.val.loc16, i64 0, i1 false), !dbg !39
// CHECK:STDOUT: call void @_COneVar_X.Main(ptr %_.var.loc16), !dbg !46
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %_.var.loc16), !dbg !39
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc18_12), !dbg !40
// CHECK:STDOUT: store i32 1, ptr %_.var.loc18_12, align 4, !dbg !40
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc18_24), !dbg !41
// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %_.var.loc18_24, ptr align 1 @X.val.loc16, i64 0, i1 false), !dbg !41
// CHECK:STDOUT: call void @_CTwoVars.Main(ptr %_.var.loc18_12, ptr %_.var.loc18_24), !dbg !47
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %_.var.loc18_24), !dbg !41
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc18_12), !dbg !40
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc20), !dbg !42
// CHECK:STDOUT: store i32 1, ptr %_.var.loc20, align 4, !dbg !42
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc27_18.2.temp), !dbg !43
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc29_18.2.temp), !dbg !43
// CHECK:STDOUT: call void @_CVarThenLet.Main(ptr %_.var.loc20, ptr @X.val.loc16), !dbg !48
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr @X.val), !dbg !43
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc20), !dbg !42
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %_.var.loc21), !dbg !44
// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %_.var.loc21, ptr align 1 @X.val.loc16, i64 0, i1 false), !dbg !44
// CHECK:STDOUT: call void @_CLetThenVar.Main(i32 1, ptr %_.var.loc21), !dbg !49
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %_.var.loc21), !dbg !44
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr @X.val), !dbg !43
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc20), !dbg !42
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %_.var.loc18_24), !dbg !41
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc18_12), !dbg !40
// CHECK:STDOUT: call void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %_.var.loc16), !dbg !39
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %_.var.loc15), !dbg !38
// CHECK:STDOUT: ret void, !dbg !50
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: ; Function Attrs: nounwind
// CHECK:STDOUT: define weak_odr void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %self) #0 !dbg !51 {
// CHECK:STDOUT: define weak_odr void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %self) #0 !dbg !51 {
// CHECK:STDOUT: entry:
// CHECK:STDOUT: ret void, !dbg !54
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: ; Function Attrs: nounwind
// CHECK:STDOUT: define weak_odr void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %self) #0 !dbg !55 {
// CHECK:STDOUT: define weak_odr void @"_COp.429fc69ea0bf165d:core.Destroy.Core"(ptr %self) #0 !dbg !55 {
// CHECK:STDOUT: entry:
// CHECK:STDOUT: ret void, !dbg !58
// CHECK:STDOUT: }
@@ -122,8 +124,8 @@ fn Call() {
// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
// CHECK:STDOUT:
// CHECK:STDOUT: ; uselistorder directives
// CHECK:STDOUT: uselistorder ptr @"_COp.429fc69ea0bf165d:core.Destroy.Core", { 3, 2, 1, 0 }
// CHECK:STDOUT: uselistorder ptr @"_COp.5e27612b9dd31a14:core.Destroy.Core", { 2, 1, 0 }
// CHECK:STDOUT: uselistorder ptr @"_COp.429fc69ea0bf165d:core.Destroy.Core", { 3, 2, 1, 0 }
// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 6, 5, 4, 3, 2, 1, 0 }
// CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 2, 1, 0 }
// CHECK:STDOUT:
@@ -176,20 +178,20 @@ fn Call() {
// CHECK:STDOUT: !40 = !DILocation(line: 18, column: 12, scope: !35)
// CHECK:STDOUT: !41 = !DILocation(line: 18, column: 24, scope: !35)
// CHECK:STDOUT: !42 = !DILocation(line: 20, column: 15, scope: !35)
// CHECK:STDOUT: !43 = !DILocation(line: 27, column: 17, scope: !35)
// CHECK:STDOUT: !43 = !DILocation(line: 29, column: 17, scope: !35)
// CHECK:STDOUT: !44 = !DILocation(line: 21, column: 23, scope: !35)
// CHECK:STDOUT: !45 = !DILocation(line: 24, column: 3, scope: !35)
// CHECK:STDOUT: !46 = !DILocation(line: 25, column: 3, scope: !35)
// CHECK:STDOUT: !47 = !DILocation(line: 26, column: 3, scope: !35)
// CHECK:STDOUT: !48 = !DILocation(line: 27, column: 3, scope: !35)
// CHECK:STDOUT: !49 = !DILocation(line: 28, column: 3, scope: !35)
// CHECK:STDOUT: !48 = !DILocation(line: 29, column: 3, scope: !35)
// CHECK:STDOUT: !49 = !DILocation(line: 30, column: 3, scope: !35)
// CHECK:STDOUT: !50 = !DILocation(line: 23, column: 1, scope: !35)
// CHECK:STDOUT: !51 = distinct !DISubprogram(name: "Op", linkageName: "_COp.429fc69ea0bf165d:core.Destroy.Core", scope: null, file: !1, line: 21, type: !12, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !52)
// CHECK:STDOUT: !51 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !52)
// CHECK:STDOUT: !52 = !{!53}
// CHECK:STDOUT: !53 = !DILocalVariable(arg: 1, scope: !51, type: !14)
// CHECK:STDOUT: !54 = !DILocation(line: 21, column: 23, scope: !51)
// CHECK:STDOUT: !55 = distinct !DISubprogram(name: "Op", linkageName: "_COp.5e27612b9dd31a14:core.Destroy.Core", scope: null, file: !1, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !56)
// CHECK:STDOUT: !53 = !DILocalVariable(arg: 1, scope: !51, type: !7)
// CHECK:STDOUT: !54 = !DILocation(line: 15, column: 15, scope: !51)
// CHECK:STDOUT: !55 = distinct !DISubprogram(name: "Op", linkageName: "_COp.429fc69ea0bf165d:core.Destroy.Core", scope: null, file: !1, line: 16, type: !12, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !56)
// CHECK:STDOUT: !56 = !{!57}
// CHECK:STDOUT: !57 = !DILocalVariable(arg: 1, scope: !55, type: !7)
// CHECK:STDOUT: !58 = !DILocation(line: 20, column: 15, scope: !55)
// CHECK:STDOUT: !57 = !DILocalVariable(arg: 1, scope: !55, type: !14)
// CHECK:STDOUT: !58 = !DILocation(line: 16, column: 13, scope: !55)
// CHECK:STDOUT:
toolchain/lower/testdata/function/generic/call_basic.carbon
Vendored
+6 -6
View File
@@ -137,6 +137,7 @@ fn M() {
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc29_6.3.temp), !dbg !51
// CHECK:STDOUT: %H.call.loc29 = call i32 @_CH.Main.5bd8d5767580997a(i32 %x), !dbg !51
// CHECK:STDOUT: store i32 %H.call.loc29, ptr %.loc29_6.3.temp, align 4, !dbg !51
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc29_6.3.temp), !dbg !51
// CHECK:STDOUT: %H.call.loc30 = call %type @_CH.Main.ee509b43cf4eb3c5(%type zeroinitializer), !dbg !60
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc31_8.3.temp), !dbg !52
// CHECK:STDOUT: %G.call = call i32 @_CG.Main.58016a73bff04416(i32 %x), !dbg !52
@@ -145,6 +146,8 @@ fn M() {
// CHECK:STDOUT: %.loc31_8.5 = load i32, ptr %.loc31_8.3.temp, align 4, !dbg !52
// CHECK:STDOUT: %H.call.loc31 = call i32 @_CH.Main.5bd8d5767580997a(i32 %.loc31_8.5), !dbg !53
// CHECK:STDOUT: store i32 %H.call.loc31, ptr %.loc31_9.3.temp, align 4, !dbg !53
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc31_9.3.temp), !dbg !53
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc31_8.3.temp), !dbg !52
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %var_f64.var), !dbg !54
// CHECK:STDOUT: store double poison, ptr %var_f64.var, align 8, !dbg !54
// CHECK:STDOUT: %.loc35_5 = load double, ptr %var_f64.var, align 8, !dbg !61
@@ -167,9 +170,6 @@ fn M() {
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr %.loc43_6.3.temp), !dbg !59
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr %c.var), !dbg !58
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %var_f64.var), !dbg !54
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc31_9.3.temp), !dbg !53
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc31_8.3.temp), !dbg !52
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc29_6.3.temp), !dbg !51
// CHECK:STDOUT: ret i32 %x, !dbg !69
// CHECK:STDOUT: }
// CHECK:STDOUT:
@@ -194,6 +194,7 @@ fn M() {
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc29_6.3.temp), !dbg !77
// CHECK:STDOUT: %H.call.loc29 = call double @_CH.Main.c27b765f2159c9a0(double %x), !dbg !77
// CHECK:STDOUT: store double %H.call.loc29, ptr %.loc29_6.3.temp, align 8, !dbg !77
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc29_6.3.temp), !dbg !77
// CHECK:STDOUT: %H.call.loc30 = call %type @_CH.Main.ee509b43cf4eb3c5(%type zeroinitializer), !dbg !86
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc31_8.3.temp), !dbg !78
// CHECK:STDOUT: %G.call = call double @_CG.Main.fa1f0912a5bbe922(double %x), !dbg !78
@@ -202,6 +203,8 @@ fn M() {
// CHECK:STDOUT: %.loc31_8.5 = load double, ptr %.loc31_8.3.temp, align 8, !dbg !78
// CHECK:STDOUT: %H.call.loc31 = call double @_CH.Main.c27b765f2159c9a0(double %.loc31_8.5), !dbg !79
// CHECK:STDOUT: store double %H.call.loc31, ptr %.loc31_9.3.temp, align 8, !dbg !79
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc31_9.3.temp), !dbg !79
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc31_8.3.temp), !dbg !78
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %var_f64.var), !dbg !80
// CHECK:STDOUT: store double poison, ptr %var_f64.var, align 8, !dbg !80
// CHECK:STDOUT: %.loc35_5 = load double, ptr %var_f64.var, align 8, !dbg !87
@@ -224,9 +227,6 @@ fn M() {
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr %.loc43_6.3.temp), !dbg !85
// CHECK:STDOUT: call void @"_COp.807eb4f2d3ed7e54:core.Destroy.Core"(ptr %c.var), !dbg !84
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %var_f64.var), !dbg !80
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc31_9.3.temp), !dbg !79
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc31_8.3.temp), !dbg !78
// CHECK:STDOUT: call void @"_COp.30d8007fdcc57f83:core.Destroy.Core"(ptr %.loc29_6.3.temp), !dbg !77
// CHECK:STDOUT: ret double %x, !dbg !95
// CHECK:STDOUT: }
// CHECK:STDOUT:
toolchain/lower/testdata/function/generic/call_basic_depth.carbon
Vendored
+1 -1
View File
@@ -82,8 +82,8 @@ fn M() -> i32 {
// CHECK:STDOUT: call void @llvm.lifetime.start.p0(ptr %.loc25_6.3.temp), !dbg !32
// CHECK:STDOUT: %H.call = call i32 @_CH.Main.5bd8d5767580997a(i32 %x), !dbg !32
// CHECK:STDOUT: store i32 %H.call, ptr %.loc25_6.3.temp, align 4, !dbg !32
// CHECK:STDOUT: call void @_CF.Main.84588f41d61dafba(i32 %x), !dbg !33
// CHECK:STDOUT: call void @"_COp.5e27612b9dd31a14:core.Destroy.Core"(ptr %.loc25_6.3.temp), !dbg !32
// CHECK:STDOUT: call void @_CF.Main.84588f41d61dafba(i32 %x), !dbg !33
// CHECK:STDOUT: ret i32 %x, !dbg !34
// CHECK:STDOUT: }
// CHECK:STDOUT: