[llvm] [ThinLTO][Bitcode] Generate import type in bitcode (PR #87600)

[Mingming Liu via llvm-commits]

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@@ -48,20 +48,20 @@
 ; First disassemble per-module summary and find out the GUID for {large_func, large_indirect_callee}.
 ;
 ; RUN: llvm-dis lib.bc -o - | FileCheck %s --check-prefix=LIB-DIS
+; LIB-DIS: [[LIBMOD:\^[0-9]+]] = module: (path: "lib.bc", hash: (0, 0, 0, 0, 0))
 ; LIB-DIS: [[LARGEFUNC:\^[0-9]+]] = gv: (name: "large_func", summaries: {{.*}}) ; guid = 2418497564662708935
 ; LIB-DIS: [[LARGEINDIRECT:\^[0-9]+]] = gv: (name: "large_indirect_callee", summaries: {{.*}}) ; guid = 14343440786664691134
 ; LIB-DIS: [[LARGEINDIRECTALIAS:\^[0-9]+]] = gv: (name: "large_indirect_callee_alias", summaries: {{.*}}, aliasee: [[LARGEINDIRECT]]
 ;
-; Secondly disassemble main's combined summary and test that large callees are
-; not imported as declarations yet.
-; TODO: Serialize declaration bit and test declaration bits are correctly set.
+; Secondly disassemble main's combined summary and verify the import type of
+; these two GUIDs are declaration.
 ;
 ; RUN: llvm-dis main.bc.thinlto.bc -o - | FileCheck %s --check-prefix=MAIN-DIS
 ;
 ; MAIN-DIS: [[LIBMOD:\^[0-9]+]] = module: (path: "lib.bc", hash: (0, 0, 0, 0, 0))
-; MAIN-DIS-NOT: [[LARGEFUNC:\^[0-9]+]] = gv: (guid: 2418497564662708935, summaries: (function: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration), insts: 8, {{.*}})))
-; MAIN-DIS-NOT: [[LARGEINDIRECT:\^[0-9]+]] = gv: (guid: 14343440786664691134, summaries: (function: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration), insts: 8, {{.*}})))
-; MAIN-DIS-NOT: [[LARGEINDIRECTALIAS:\^[0-9]+]] = gv: (guid: 16730173943625350469, summaries: (alias: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration)
+; MAIN-DIS: [[LARGEFUNC:\^[0-9]+]] = gv: (guid: 2418497564662708935, summaries: (function: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration), insts: 8, {{.*}})))
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minglotus-6 wrote:

I updated the test case as suggested, and it's indeed an interesting case, and actually needs a follow-up fix. As shown by the updated test, function alias summary has 'null' aliasee. I'm preparing a fix.

For function alias definition, postlink pipeline clones the aliasee function and keeps using alias's name. I'm looking into whether it makes sense to rewrite the callee to aliasee (for indirect calls we need to update value profiles).

https://github.com/llvm/llvm-project/pull/87600