Author: Joseph Huber Date: 2024-10-29T15:34:28-05:00 New Revision: a78861fc55d18046989ff4d624a037e9181da170
URL: https://github.com/llvm/llvm-project/commit/a78861fc55d18046989ff4d624a037e9181da170 DIFF: https://github.com/llvm/llvm-project/commit/a78861fc55d18046989ff4d624a037e9181da170.diff LOG: [NvlinkWrapper] Add support for `--undefined` (#113934) Summary: This flag is pretty canonical in ELF linkers, it allows us to force the link job to extract a library if it defines a specific symbol. This is mostly useful for letting us forcibly extract things that don't fit the normal model (i.e. kernels) from static libraries. Added: Modified: clang/test/Driver/nvlink-wrapper.c clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp clang/tools/clang-nvlink-wrapper/NVLinkOpts.td Removed: ################################################################################ diff --git a/clang/test/Driver/nvlink-wrapper.c b/clang/test/Driver/nvlink-wrapper.c index 2b0993caee4248..79f4a6641732f7 100644 --- a/clang/test/Driver/nvlink-wrapper.c +++ b/clang/test/Driver/nvlink-wrapper.c @@ -21,12 +21,13 @@ int bar() { } #else extern int y; -int __attribute__((visibility("hidden"))) x = 999; +extern int x; int baz() { return y + x; } #endif // Create various inputs to test basic linking and LTO capabilities. Creating a // CUDA binary requires access to the `ptxas` executable, so we just use x64. +// RUN: %clang -cc1 %s -triple nvptx64-nvidia-cuda -emit-llvm-bc -o %t.o // RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -DX -o %t-x.o // RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -DY -o %t-y.o // RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -DZ -o %t-z.o @@ -36,6 +37,7 @@ int baz() { return y + x; } // RUN: llvm-ar rcs %t-y.a %t-y.o // RUN: llvm-ar rcs %t-z.a %t-z.o // RUN: llvm-ar rcs %t-w.a %t-w.o +// RUN: llvm-ar rcs %t-u.a %t-u.o // // Check that we forward any unrecognized argument to 'nvlink'. @@ -49,11 +51,16 @@ int baz() { return y + x; } // `libx.a` and `liby.a` because extern weak symbols do not extract and `libz.a` // is not used at all. // -// RUN: clang-nvlink-wrapper --dry-run %t-x.a %t-u.o %t-y.a %t-z.a %t-w.a \ +// RUN: clang-nvlink-wrapper --dry-run %t-x.a %t-u.a %t-y.a %t-z.a %t-w.a %t.o \ // RUN: -arch sm_52 -o a.out 2>&1 | FileCheck %s --check-prefix=LINK // LINK: nvlink{{.*}} -arch sm_52 -o a.out [[INPUT:.+]].cubin {{.*}}-x-{{.*}}.cubin{{.*}}-y-{{.*}}.cubin -// RUN: %clang -cc1 %s -triple nvptx64-nvidia-cuda -emit-llvm-bc -o %t.o +// +// Same as above but we use '--undefined' to forcibly extract 'libz.a' +// +// RUN: clang-nvlink-wrapper --dry-run %t-x.a %t-u.a %t-y.a %t-z.a %t-w.a %t.o \ +// RUN: -u z -arch sm_52 -o a.out 2>&1 | FileCheck %s --check-prefix=LINK +// UNDEFINED: nvlink{{.*}} -arch sm_52 -o a.out [[INPUT:.+]].cubin {{.*}}-x-{{.*}}.cubin{{.*}}-y-{{.*}}.cubin{{.*}}-z-{{.*}}.cubin // // Check that the LTO interface works and properly preserves symbols used in a diff --git a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp index b9767a7a03d0b5..bc191afdca739d 100644 --- a/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp +++ b/clang/tools/clang-nvlink-wrapper/ClangNVLinkWrapper.cpp @@ -250,6 +250,7 @@ struct Symbol { }; Symbol() : File(), Flags(None), UsedInRegularObj(false) {} + Symbol(Symbol::Flags Flags) : File(), Flags(Flags), UsedInRegularObj(true) {} Symbol(MemoryBufferRef File, const irsymtab::Reader::SymbolRef Sym) : File(File), Flags(0), UsedInRegularObj(false) { @@ -535,6 +536,8 @@ Expected<SmallVector<StringRef>> getInput(const ArgList &Args) { bool Extracted = true; StringMap<Symbol> SymTab; + for (auto &Sym : Args.getAllArgValues(OPT_u)) + SymTab[Sym] = Symbol(Symbol::Undefined); SmallVector<std::unique_ptr<MemoryBuffer>> LinkerInput; while (Extracted) { Extracted = false; diff --git a/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td b/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td index a80c5937b42992..6de1a25c14f8be 100644 --- a/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td +++ b/clang/tools/clang-nvlink-wrapper/NVLinkOpts.td @@ -43,11 +43,11 @@ def plugin : JoinedOrSeparate<["--", "-"], "plugin">, Flags<[HelpHidden, WrapperOnlyOption]>; def arch : Separate<["--", "-"], "arch">, - HelpText<"Specify the 'sm_' name of the target architecture.">; + HelpText<"Specify the 'sm_' name of the target architecture">; def : Joined<["--", "-"], "plugin-opt=mcpu=">, Flags<[HelpHidden, WrapperOnlyOption]>, Alias<arch>; -def g : Flag<["-"], "g">, HelpText<"Specify that this was a debug compile.">; +def g : Flag<["-"], "g">, HelpText<"Specify that this was a debug compile">; def debug : Flag<["--"], "debug">, Alias<g>; def lto_emit_llvm : Flag<["--"], "lto-emit-llvm">, Flags<[WrapperOnlyOption]>, @@ -55,6 +55,9 @@ def lto_emit_llvm : Flag<["--"], "lto-emit-llvm">, Flags<[WrapperOnlyOption]>, def lto_emit_asm : Flag<["--"], "lto-emit-asm">, Flags<[WrapperOnlyOption]>, HelpText<"Emit assembly code">; +def u : JoinedOrSeparate<["-"], "u">, HelpText<"Force undefined symbol during linking">; +def undefined : JoinedOrSeparate<["--"], "undefined">, Alias<u>; + def O : Joined<["--", "-"], "plugin-opt=O">, Flags<[WrapperOnlyOption]>, MetaVarName<"<O0, O1, O2, or O3>">, HelpText<"Optimization level for LTO">; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
