Skip to content

Set lambda linkage to LinkOnceODR (was Internal) #5045

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kinke merged 4 commits into from
Feb 3, 2026
Merged

Set lambda linkage to LinkOnceODR (was Internal) #5045

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
82d8e07
Set lambda linkage to LinkOnceODR (was Internal)
JohanEngelen Jan 19, 2026
ab1a780
Fix lambda tests for linkage change
JohanEngelen Jan 20, 2026
4dc2ca1
fixup
JohanEngelen Feb 2, 2026
277ebcc
fixup2
kinke Feb 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 2 additions & 5 deletions gen/tollvm.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -229,18 +229,15 @@ LLGlobalValue::LinkageTypes DtoLinkageOnly(Dsymbol *sym) {
return LLGlobalValue::InternalLinkage;

/* Function (incl. delegate) literals are emitted into each referencing
* compilation unit, so use internal linkage for all lambdas and all global
* compilation unit, so use linkonce_odr for all lambdas and all global
* variables they define.
* This makes sure these symbols don't accidentally collide when linking
* object files compiled by different compiler invocations (lambda mangles
* aren't stable - see https://issues.dlang.org/show_bug.cgi?id=23722).
*/
auto potentialLambda = sym;
if (auto vd = sym->isVarDeclaration())
if (vd->isDataseg())
potentialLambda = vd->toParent2();
if (potentialLambda->isFuncLiteralDeclaration())
return LLGlobalValue::InternalLinkage;
return LLGlobalValue::LinkOnceODRLinkage;

if (sym->isInstantiated())
return templateLinkage;
Expand Down
18 changes: 9 additions & 9 deletions tests/codegen/lambdas_gh3648.d
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
// Tests that lambdas and contained globals are emitted with internal linkage.
// Tests that lambdas and contained globals are emitted as linkonce_odr.

// RUN: %ldc -output-ll -of=%t.ll %s && FileCheck %s < %t.ll

Expand All @@ -25,22 +25,22 @@ void foo()
}(123);
}

// the global variables should be defined as internal:
// CHECK: _D14lambdas_gh364815__lambda_L5_C12FZ10global_bari{{.*}} = internal thread_local global
// CHECK: _D14lambdas_gh364816__lambda_L10_C20FZ18global_bar_inlinedOi{{.*}} = internal global
// CHECK: _D14lambdas_gh36483fooFZ__T15__lambda_L21_C5TiZQuFiZ12lambda_templi{{.*}} = internal global
// the global variables should be defined as linkonce_odr:
// CHECK: _D14lambdas_gh364815__lambda_L5_C12FZ10global_bari{{.*}} = linkonce_odr {{(hidden )?}}thread_local global
// CHECK: _D14lambdas_gh364816__lambda_L10_C20FZ18global_bar_inlinedOi{{.*}} = linkonce_odr {{(hidden )?}}global
// CHECK: _D14lambdas_gh36483fooFZ__T15__lambda_L21_C5TiZQuFiZ12lambda_templi{{.*}} = linkonce_odr {{(hidden )?}}global

// foo() should only call two lambdas:
// CHECK: define {{.*}}_D14lambdas_gh36483fooFZv
// CHECK-NEXT: call {{.*}}__lambda_L5_C12
// CHECK-NEXT: call {{.*}}__T15__lambda_L21_C5
// CHECK-NEXT: ret void

// bar() should be defined as internal:
// CHECK: define internal {{.*}}__lambda_L5_C12
// bar() should be defined as linkonce_odr:
// CHECK: define linkonce_odr {{.*}}__lambda_L5_C12

// bar_inlined() should NOT have made it to the .ll:
// CHECK-NOT: define {{.*}}__lambda_L10_C20

// the template lambda instance should be defined as internal:
// CHECK: define internal {{.*}}__T15__lambda_L21_C5
// the template lambda instance should be defined as linkonce_odr:
// CHECK: define linkonce_odr {{.*}}__T15__lambda_L21_C5
12 changes: 6 additions & 6 deletions tests/codegen/lambdas_gh3648b.d
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
// Tests that *imported* lambdas and contained globals are emitted with internal linkage.
// Tests that *imported* lambdas and contained globals are emitted as linkonce_odr.

// RUN: %ldc -output-ll -of=%t.ll %s -I%S && FileCheck %s < %t.ll

Expand All @@ -10,17 +10,17 @@ void foo()
bar_inlined();
}

// the global variables should be defined as internal:
// CHECK: _D14lambdas_gh364815__lambda_L5_C12FZ10global_bari{{.*}} = internal thread_local global
// CHECK: _D14lambdas_gh364816__lambda_L10_C20FZ18global_bar_inlinedOi{{.*}} = internal global
// the global variables should be defined as linkonce_odr:
// CHECK: _D14lambdas_gh364815__lambda_L5_C12FZ10global_bari{{.*}} = linkonce_odr {{(hidden )?}}thread_local global
// CHECK: _D14lambdas_gh364816__lambda_L10_C20FZ18global_bar_inlinedOi{{.*}} = linkonce_odr {{(hidden )?}}global

// foo() should only call one lambda:
// CHECK: define {{.*}}_D15lambdas_gh3648b3fooFZv
// CHECK-NEXT: call {{.*}}__lambda_L5_C12
// CHECK-NEXT: ret void

// bar() should be defined as internal:
// CHECK: define internal {{.*}}__lambda_L5_C12
// bar() should be defined as linkonce_odr:
// CHECK: define linkonce_odr {{.*}}__lambda_L5_C12

// bar_inlined() should NOT have made it to the .ll:
// CHECK-NOT: define {{.*}}__lambda_L10_C20