[clang] [SPIR-V] Prefer llvm-spirv-<LLVM_VERSION_MAJOR> tool (PR #77897)

[Henry Linjamäki via cfe-commits]

https://github.com/linehill created https://github.com/llvm/llvm-project/pull/77897

Prefer using `llvm-spirv-<LLVM_VERSION_MAJOR>` tool (i.e. `llvm-spirv-18`) over plain `llvm-spirv`. If the versioned tool is not found in PATH, fall back to use the plain `llvm-spirv`.

An issue with the using `llvm-spirv` is that the one found in PATH might be compiled against older LLVM version which could lead to crashes or obscure bugs. For example, `llvm-spirv` distributed by Ubuntu links against different LLVM version depending on the Ubuntu release (LLVM-10 in 20.04LTS, LLVM-13 in 22.04LTS).

>From 6165987ab890156a503d7afa38ad5c88510368b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henry=20Linjam=C3=A4ki?= <henry.mikael.linjamaki at intel.com>
Date: Thu, 21 Dec 2023 08:43:16 +0200
Subject: [PATCH] [SPIR-V] Prefer llvm-spirv-<LLVM_VERSION_MAJOR> tool

Prefer using `llvm-spirv-<LLVM_VERSION_MAJOR>` tool
(i.e. `llvm-spirv-18`) over plain `llvm-spirv`. If the versioned tool
is not found in PATH, fall back to use the plain `llvm-spirv`.

An issue with the using `llvm-spirv` is that the one found in PATH
might be compiled against older LLVM version which could lead to
crashes or obscure bugs. For example, `llvm-spirv` distributed by
Ubuntu links against different LLVM version depending on the Ubuntu
release (LLVM-10 in 20.04LTS, LLVM-13 in 22.04LTS).
---
 clang/lib/Driver/ToolChains/SPIRV.cpp  | 12 ++++++++++--
 clang/test/Driver/hipspv-toolchain.hip | 13 +++++++++++++
 clang/test/Driver/spirv-toolchain.cl   | 10 ++++++++++
 clang/test/lit.site.cfg.py.in          |  1 +
 4 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/SPIRV.cpp b/clang/lib/Driver/ToolChains/SPIRV.cpp
index 27de69550853cf..ce900600cbee51 100644
--- a/clang/lib/Driver/ToolChains/SPIRV.cpp
+++ b/clang/lib/Driver/ToolChains/SPIRV.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 #include "SPIRV.h"
 #include "CommonArgs.h"
+#include "clang/Basic/Version.h"
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/InputInfo.h"
@@ -32,8 +33,15 @@ void SPIRV::constructTranslateCommand(Compilation &C, const Tool &T,
 
   CmdArgs.append({"-o", Output.getFilename()});
 
-  const char *Exec =
-      C.getArgs().MakeArgString(T.getToolChain().GetProgramPath("llvm-spirv"));
+  // Try to find "llvm-spirv-<LLVM_VERSION_MAJOR>". Otherwise, fall back to
+  // plain "llvm-spirv".
+  using namespace std::string_literals;
+  auto VersionedTool = "llvm-spirv-"s + std::to_string(LLVM_VERSION_MAJOR);
+  std::string ExeCand = T.getToolChain().GetProgramPath(VersionedTool.c_str());
+  if (!llvm::sys::fs::can_execute(ExeCand))
+    ExeCand = T.getToolChain().GetProgramPath("llvm-spirv");
+
+  const char *Exec = C.getArgs().MakeArgString(ExeCand);
   C.addCommand(std::make_unique<Command>(JA, T, ResponseFileSupport::None(),
                                          Exec, CmdArgs, Input, Output));
 }
diff --git a/clang/test/Driver/hipspv-toolchain.hip b/clang/test/Driver/hipspv-toolchain.hip
index bfae41049ba4dd..5f6dcc069afe8b 100644
--- a/clang/test/Driver/hipspv-toolchain.hip
+++ b/clang/test/Driver/hipspv-toolchain.hip
@@ -34,3 +34,16 @@
 // CHECK-SAME: "-o" [[OBJ_HOST:".*o"]] "-x" "hip"
 
 // CHECK: {{".*ld.*"}} {{.*}}[[OBJ_HOST]]
+
+//-----------------------------------------------------------------------------
+// Check llvm-spirv-<LLVM_VERSION_MAJOR> is used if it is found in PATH.
+// RUN: mkdir -p %t/versioned
+// RUN: touch %t/versioned/llvm-spirv-%llvm-version-major \
+// RUN:   && chmod +x %t/versioned/llvm-spirv-%llvm-version-major
+// RUN: env "PATH=%t/versioned" %clang -### -target x86_64-linux-gnu \
+// RUN:   --offload=spirv64 --hip-path=%S/Inputs/hipspv -nohipwrapperinc \
+// RUN:   %s 2>&1 \
+// RUN:   | FileCheck -DVERSION=%llvm-version-major \
+// RUN:   --check-prefix=VERSIONED %s
+
+// VERSIONED: {{.*}}llvm-spirv-[[VERSION]]
diff --git a/clang/test/Driver/spirv-toolchain.cl b/clang/test/Driver/spirv-toolchain.cl
index db3ee4d3fe02f8..de818177cb19f1 100644
--- a/clang/test/Driver/spirv-toolchain.cl
+++ b/clang/test/Driver/spirv-toolchain.cl
@@ -77,3 +77,13 @@
 
 // XTOR: {{llvm-spirv.*"}}
 // BACKEND-NOT: {{llvm-spirv.*"}}
+
+//-----------------------------------------------------------------------------
+// Check llvm-spirv-<LLVM_VERSION_MAJOR> is used if it is found in PATH.
+// RUN: mkdir -p %t/versioned
+// RUN: touch %t/versioned/llvm-spirv-%llvm-version-major \
+// RUN:   && chmod +x %t/versioned/llvm-spirv-%llvm-version-major
+// RUN: env "PATH=%t/versioned" %clang -### --target=spirv64 -x cl -c %s 2>&1 \
+// RUN:   | FileCheck -DVERSION=%llvm-version-major --check-prefix=VERSIONED %s
+
+// VERSIONED: {{.*}}llvm-spirv-[[VERSION]]
diff --git a/clang/test/lit.site.cfg.py.in b/clang/test/lit.site.cfg.py.in
index ef75770a2c3c9a..b4e88096aaa0f3 100644
--- a/clang/test/lit.site.cfg.py.in
+++ b/clang/test/lit.site.cfg.py.in
@@ -41,6 +41,7 @@ config.llvm_external_lit = path(r"@LLVM_EXTERNAL_LIT@")
 config.standalone_build = @CLANG_BUILT_STANDALONE@
 config.ppc_linux_default_ieeelongdouble = @PPC_LINUX_DEFAULT_IEEELONGDOUBLE@
 config.have_llvm_driver = @LLVM_TOOL_LLVM_DRIVER_BUILD@
+config.substitutions.append(("%llvm-version-major", "@LLVM_VERSION_MAJOR@"))
 
 import lit.llvm
 lit.llvm.initialize(lit_config, config)