Consider this example program with an inline function "foo": ==> foo.h <== extern int global; __inline void foo() { ++global; } void bar(); ==> pdb_comdat_main.c <== #include "foo.h" int main(void) { foo(); bar(); return 42; } ==> pdb_comdat_bar.c <== #include "foo.h" void bar(void) { foo(); } Both object files will contain debug info for foo, but only the debug info from pdb_comdat_main.obj should be included in the PDB. RUN: rm -rf %t && mkdir -p %t && cd %t RUN: yaml2obj %S/Inputs/pdb_comdat_main.yaml -o pdb_comdat_main.obj RUN: yaml2obj %S/Inputs/pdb_comdat_bar.yaml -o pdb_comdat_bar.obj RUN: lld-link pdb_comdat_main.obj pdb_comdat_bar.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main RUN: llvm-pdbutil dump -l -symbols -globals %t.pdb | FileCheck %s CHECK: Lines CHECK: ============================================================ CHECK-LABEL: Mod 0000 | `{{.*}}pdb_comdat_main.obj`: CHECK: c:\src\llvm-project\build\pdb_comdat_main.c (MD5: F969E51BBE373436D81492EB61387F36) CHECK: c:\src\llvm-project\build\foo.h (MD5: D74D834EFAC3AE2B45E606A8320B1D5C) CHECK-LABEL: Mod 0001 | `{{.*}}pdb_comdat_bar.obj`: CHECK: c:\src\llvm-project\build\pdb_comdat_bar.c (MD5: 365279DB4FCBEDD721BBFC3B14A953C2) CHECK-NOT: c:\src\llvm-project\build\foo.h CHECK-LABEL: Mod 0002 | `* Linker *`: CHECK-LABEL: Global Symbols CHECK-NEXT: ============================================================ CHECK-NEXT: Records CHECK-NEXT: 84 | S_PROCREF [size = 20] `main` CHECK-NEXT: module = 1, sum name = 0, offset = 120 CHECK-NEXT: 148 | S_PROCREF [size = 20] `bar` CHECK-NEXT: module = 2, sum name = 0, offset = 120 CHECK-NEXT: 128 | S_PROCREF [size = 20] `foo` CHECK-NEXT: module = 1, sum name = 0, offset = 208 CHECK-NEXT: 104 | S_GDATA32 [size = 24] `global` CHECK-NEXT: type = 0x0074 (int), addr = 0003:0000 CHECK-NEXT: 168 | S_GDATA32 [size = 24] `global` CHECK-NEXT: type = 0x0074 (int), addr = 0003:0000 CHECK: Symbols CHECK: ============================================================ CHECK-LABEL: Mod 0000 | `{{.*}}pdb_comdat_main.obj`: CHECK: 4 | S_OBJNAME [size = 56] sig=0, `C:\src\llvm-project\build\pdb_comdat_main.obj` CHECK: 60 | S_COMPILE3 [size = 60] CHECK: machine = intel x86-x64, Ver = Microsoft (R) Optimizing Compiler, language = c CHECK: frontend = 19.0.24215.1, backend = 19.0.24215.1 CHECK: flags = security checks | hot patchable CHECK: 120 | S_GPROC32 [size = 44] `main` CHECK: parent = 0, end = 196, addr = 0001:0000, code size = 24 CHECK: debug start = 4, debug end = 19, flags = none CHECK: 164 | S_FRAMEPROC [size = 32] CHECK: size = 40, padding size = 0, offset to padding = 0 CHECK: bytes of callee saved registers = 0, exception handler addr = 0000:0000 CHECK: flags = has async eh | opt speed CHECK: 196 | S_END [size = 4] CHECK: 200 | S_BUILDINFO [size = 8] BuildId = `0x100A` CHECK: 208 | S_GPROC32 [size = 44] `foo` CHECK: parent = 0, end = 284, addr = 0001:0032, code size = 15 CHECK: debug start = 0, debug end = 14, flags = none CHECK: 252 | S_FRAMEPROC [size = 32] CHECK: size = 0, padding size = 0, offset to padding = 0 CHECK: bytes of callee saved registers = 0, exception handler addr = 0000:0000 CHECK: flags = marked inline | has async eh | opt speed CHECK: 284 | S_END [size = 4] CHECK-LABEL: Mod 0001 | `{{.*}}pdb_comdat_bar.obj`: CHECK: 4 | S_OBJNAME [size = 56] sig=0, `C:\src\llvm-project\build\pdb_comdat_bar.obj` CHECK: 60 | S_COMPILE3 [size = 60] CHECK: machine = intel x86-x64, Ver = Microsoft (R) Optimizing Compiler, language = c CHECK: frontend = 19.0.24215.1, backend = 19.0.24215.1 CHECK: flags = security checks | hot patchable CHECK: 120 | S_GPROC32 [size = 44] `bar` CHECK: parent = 0, end = 196, addr = 0001:0048, code size = 14 CHECK: debug start = 4, debug end = 9, flags = none CHECK: 164 | S_FRAMEPROC [size = 32] CHECK: size = 40, padding size = 0, offset to padding = 0 CHECK: bytes of callee saved registers = 0, exception handler addr = 0000:0000 CHECK: flags = has async eh | opt speed CHECK: 196 | S_END [size = 4] CHECK: 200 | S_BUILDINFO [size = 8] BuildId = `0x100D` CHECK-NOT: S_GPROC32 {{.*}} `foo` CHECK-LABEL: Mod 0002 | `* Linker *`: Reorder the object files and verify that the other table is selected. RUN: lld-link pdb_comdat_bar.obj pdb_comdat_main.obj -out:t.exe -debug -pdb:t.pdb -nodefaultlib -entry:main RUN: llvm-pdbutil dump -l t.pdb | FileCheck %s --check-prefix=REORDER REORDER-LABEL: Mod 0000 | `{{.*}}pdb_comdat_bar.obj`: REORDER: c:\src\llvm-project\build\pdb_comdat_bar.c (MD5: 365279DB4FCBEDD721BBFC3B14A953C2) REORDER: c:\src\llvm-project\build\foo.h (MD5: D74D834EFAC3AE2B45E606A8320B1D5C) REORDER-LABEL: Mod 0001 | `{{.*}}pdb_comdat_main.obj`: REORDER: c:\src\llvm-project\build\pdb_comdat_main.c REORDER-NOT: c:\src\llvm-project\build\foo.h REORDER-LABEL: Mod 0002 | `* Linker *`: Make sure that we don't crash on non-prevailing debug sections if -debug is not enabled. RUN: lld-link pdb_comdat_main.obj pdb_comdat_bar.obj -out:%t.exe -nodefaultlib -entry:main