[clang] [llvm] [LinkerWrapper] Allow 'all' as a generic bundled architecture (PR #81193)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/81193

Summary:
Currently, the linker wrapper sourts input files into different link
jobs according to their architectures. Here we assume each architecture
is a unique and incompatible link job unless they are specifically
marked compatible. This patch simply adds an `all` target to represent
an architecture that should be linked against every single other
architecture.

This will be useful for modelling generic IR such as the ROCm device
libraries or the NVPTX libdevice.


>From dcf508138c7ccf7877e63d2c60bd44196ec95468 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Thu, 8 Feb 2024 15:37:10 -0600
Subject: [PATCH] [LinkerWrapper] Allow 'all' as a generic bundled architecture

Summary:
Currently, the linker wrapper sourts input files into different link
jobs according to their architectures. Here we assume each architecture
is a unique and incompatible link job unless they are specifically
marked compatible. This patch simply adds an `all` target to represent
an architecture that should be linked against every single other
architecture.

This will be useful for modelling generic IR such as the ROCm device
libraries or the NVPTX libdevice.
---
 clang/test/Driver/linker-wrapper.c | 16 ++++++++++++++++
 llvm/lib/Object/OffloadBinary.cpp  |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/clang/test/Driver/linker-wrapper.c b/clang/test/Driver/linker-wrapper.c
index 010001b83d7c2d..647629a5969bdc 100644
--- a/clang/test/Driver/linker-wrapper.c
+++ b/clang/test/Driver/linker-wrapper.c
@@ -172,6 +172,22 @@ __attribute__((visibility("protected"), used)) int x;
 // AMD-TARGET-ID: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a:xnack+ -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
 // AMD-TARGET-ID: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a:xnack- -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
 
+// RUN: clang-offload-packager -o %t-lib.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=all
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t.o -fembed-offload-object=%t-lib.out
+// RUN: llvm-ar rcs %t.a %t.o
+// RUN: clang-offload-packager -o %t1.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx90a
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t1.o -fembed-offload-object=%t1.out
+// RUN: clang-offload-packager -o %t2.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx908
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t2.o -fembed-offload-object=%t2.out
+// RUN: clang-linker-wrapper --host-triple=x86_64-unknown-linux-gnu --dry-run \
+// RUN:   --linker-path=/usr/bin/ld -- %t1.o %t2.o %t.a -o a.out 2>&1 | FileCheck %s --check-prefix=ARCH-ALL
+
+// ARCH-ALL: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx908 -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
+// ARCH-ALL: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
+
 // RUN: clang-offload-packager -o %t.out \
 // RUN:   --image=file=%t.elf.o,kind=openmp,triple=x86_64-unknown-linux-gnu \
 // RUN:   --image=file=%t.elf.o,kind=openmp,triple=x86_64-unknown-linux-gnu
diff --git a/llvm/lib/Object/OffloadBinary.cpp b/llvm/lib/Object/OffloadBinary.cpp
index 22d604b125c583..58b9b39e0d2721 100644
--- a/llvm/lib/Object/OffloadBinary.cpp
+++ b/llvm/lib/Object/OffloadBinary.cpp
@@ -355,6 +355,10 @@ bool object::areTargetsCompatible(const OffloadFile::TargetID &LHS,
   if (LHS.first != RHS.first)
     return false;
 
+  // If the architecture is "all" we assume it is always compatible.
+  if (LHS.second.equals("all") || RHS.second.equals("all"))
+    return true;
+
   // Only The AMDGPU target requires additional checks.
   llvm::Triple T(LHS.first);
   if (!T.isAMDGPU())