https://github.com/erichkeane created https://github.com/llvm/llvm-project/pull/224378
These attributes modified the linkage of functions in certain cases that caused us to, ironically, skip emitting something when we picked it up via PCH during self-build. This patch just copies/pastes the code from classic codegen. >From dfd409d393eca83f77be793ea7884df70fac1c54 Mon Sep 17 00:00:00 2001 From: erichkeane <[email protected]> Date: Thu, 17 Sep 2026 09:19:59 -0700 Subject: [PATCH] [CIR] Correct the behavior of 'shouldEmitFunction' with always/noinline These attributes modified the linkage of functions in certain cases that caused us to, ironically, skip emitting something when we picked it up via PCH during self-build. This patch just copies/pastes the code from classic codegen. --- clang/lib/CIR/CodeGen/CIRGenModule.cpp | 14 +++++ .../noinline-available-externally-skip.cpp | 51 +++++++++++++++++++ 2 files changed, 65 insertions(+) create mode 100644 clang/test/CIR/CodeGen/noinline-available-externally-skip.cpp diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp index 3af6ce4ce6e94..03a799ccc74f1 100644 --- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp @@ -1705,6 +1705,20 @@ bool CIRGenModule::shouldEmitFunction(GlobalDecl gd) { if (fd->isInlineBuiltinDeclaration()) return true; + if (codeGenOpts.OptimizationLevel == 0 && !fd->hasAttr<AlwaysInlineAttr>()) + return false; + + // We don't import function bodies from other named module units since that + // behavior may break ABI compatibility of the current unit. + if (const Module *m = fd->getOwningModule(); + m && m->getTopLevelModule()->isNamedModule() && + getASTContext().getCurrentNamedModule() != m->getTopLevelModule()) { + errorNYI(fd->getSourceRange(), "should emit function in a named module"); + } + + if (fd->hasAttr<NoInlineAttr>()) + return false; + // PR9614 / glibc btowc workaround: an available_externally function whose // body just calls itself (via asm label or __builtin_* lowering on the // same name) is not a valid stand-in for the real implementation. Drop diff --git a/clang/test/CIR/CodeGen/noinline-available-externally-skip.cpp b/clang/test/CIR/CodeGen/noinline-available-externally-skip.cpp new file mode 100644 index 0000000000000..0a7821c61c150 --- /dev/null +++ b/clang/test/CIR/CodeGen/noinline-available-externally-skip.cpp @@ -0,0 +1,51 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -O0 -disable-llvm-passes -emit-cir %s -o %t.cir +// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR,CIRO0 + +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -O0 -disable-llvm-passes -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --input-file=%t-cir.ll %s --check-prefix=LLVM,LLVMO0 + +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O0 -disable-llvm-passes -emit-llvm %s -o %t.ll +// RUN: FileCheck --input-file=%t.ll %s --check-prefix=LLVM,LLVMO0 + +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -O2 -disable-llvm-passes -emit-cir %s -o %t.cir +// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR,CIRO2 + +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -O2 -disable-llvm-passes -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --input-file=%t-cir.ll %s --check-prefix=LLVM,LLVMO2 + +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -O2 -disable-llvm-passes -emit-llvm %s -o %t.ll +// RUN: FileCheck --input-file=%t.ll %s --check-prefix=LLVM,LLVMO2 + +template <typename T> +class Holder { + T val; +public: + explicit Holder(T v) : val(v) {} + // NOT defined. + // CIR-DAG: cir.func private @_ZNK6HolderIiE4dumpEv{{.*}}attributes {{{.*}}}{{[^{]*}}{{$}} + // LLVM-DAG: declare void @_ZNK6HolderIiE4dumpEv + __attribute__((noinline)) void dump() const {} + + // ONLY defined in O2: + // CIRO0-DAG: cir.func private @_ZNK6HolderIiE4showEv{{.*}}attributes {{{.*}}}{{[^{]*}}{{$}} + // CIRO2-DAG: cir.func available_externally @_ZNK6HolderIiE4showEv{{.*}}attributes {{{.*}}} { + // LLVMO0-DAG: declare void @_ZNK6HolderIiE4showEv + // LLVMO2-DAG: define available_externally void @_ZNK6HolderIiE4showEv + void show() const {} + + // CIR-DAG: cir.func always_inline available_externally @_ZNK6HolderIiE18dump_always_inlineEv{{.*}}attributes {{{.*}}} { + // LLVM-DAG: define available_externally void @_ZNK6HolderIiE18dump_always_inlineEv + __attribute__((always_inline)) void dump_always_inline() const {} +}; + +// Suppresses instantiation in this TU; dump() and show() are available_externally. +extern template class Holder<int>; + +// Normal Definition (wildcard is no_inline, added in O0) +// CIR-DAG: cir.func {{.*}}dso_local @_Z6callerP6HolderIiE{{.*}} attributes {{{.*}}} { +// LLVM-DAG: define {{.*}}dso_local void @_Z6callerP6HolderIiE +void caller(Holder<int> *h) { + h->dump_always_inline(); + h->dump(); + h->show(); +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
