[clang] [Driver] Always use gas with -fno-integrated-as on Solaris (PR #65489)

[via cfe-commits]

https://github.com/rorth created https://github.com/llvm/llvm-project/pull/65489:

`clang -fno-integrated-as` doesn't currently work on Solaris: it doesn't even select between 32 and 64-bit objects.  Besides, Solaris has both the native assembler (`/usr/bin/as`) and the GNU assembler (`/usr/bin/gas` resp. `/usr/gnu/bin/as`).  The native sparc and x86 assemblers aren't compatible with `clang`'s assembler syntax to varying degrees, and the command line options for `as` and `gas` are completely different.

Therefore this patch chooses to always use `gas` on Solaris, using `gnutools::Assembler::ConstructJob` to pass the correct options.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, and `x86_64-pc-linux-gnu`.

>From b867ca65e585427a6d02c245d90797a08f6dfc8e Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at CeBiTec.Uni-Bielefeld.DE>
Date: Wed, 6 Sep 2023 16:35:27 +0200
Subject: [PATCH] [Driver] Always use gas with -fno-integrated-as on Solaris

`clang -fno-integrated-as` doesn't currently work on Solaris: it doesn't
even select between 32 or 64-bit objects.  Besides, Solaris has both the
native assembler (`/usr/bin/as`) and the GNU assembler (`/usr/bin/gas`
resp. `/usr/gnu/bin/as`).  The native sparc and x86 assemblers aren't
compatible with `clang`'s assembler syntax to varying degrees, and the
command line options for `as` and `gas` are completely different.

Therefore this patch chooses to always use `gas` on Solaris, using
`gnutools::Assembler::ConstructJob` to pass the correct options.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, and
`x86_64-pc-linux-gnu`.
---
 clang/lib/Driver/ToolChains/Gnu.cpp     |  4 ++++
 clang/lib/Driver/ToolChains/Solaris.cpp | 17 +++--------------
 clang/lib/Driver/ToolChains/Solaris.h   |  5 ++---
 clang/test/Driver/solaris-as.c          | 11 +++++++++++
 4 files changed, 20 insertions(+), 17 deletions(-)
 create mode 100644 clang/test/Driver/solaris-as.c

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index d215dd77921778..7aeb8e29ebc557 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -700,6 +700,10 @@ void tools::gnutools::Assembler::ConstructJob(Compilation &C,
   unsigned PICLevel;
   bool IsPIE;
   const char *DefaultAssembler = "as";
+  // Enforce GNU as on Solaris; the native assembler's input syntax isn't fully
+  // compatible.
+  if (getToolChain().getTriple().isOSSolaris())
+    DefaultAssembler = "gas";
   std::tie(RelocationModel, PICLevel, IsPIE) =
       ParsePICArgs(getToolChain(), Args);
 
diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp
index a22e4c2e47b87e..30b79b4d90e011 100644
--- a/clang/lib/Driver/ToolChains/Solaris.cpp
+++ b/clang/lib/Driver/ToolChains/Solaris.cpp
@@ -8,6 +8,7 @@
 
 #include "Solaris.h"
 #include "CommonArgs.h"
+#include "Gnu.h"
 #include "clang/Basic/LangStandard.h"
 #include "clang/Config/config.h"
 #include "clang/Driver/Compilation.h"
@@ -32,20 +33,8 @@ void solaris::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                       const InputInfoList &Inputs,
                                       const ArgList &Args,
                                       const char *LinkingOutput) const {
-  claimNoWarnArgs(Args);
-  ArgStringList CmdArgs;
-
-  Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
-
-  CmdArgs.push_back("-o");
-  CmdArgs.push_back(Output.getFilename());
-
-  for (const auto &II : Inputs)
-    CmdArgs.push_back(II.getFilename());
-
-  const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
-  C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
-                                         Exec, CmdArgs, Inputs, Output));
+  // Just call the Gnu version, which enforces gas on Solaris.
+  gnutools::Assembler::ConstructJob(C, JA, Output, Inputs, Args, LinkingOutput);
 }
 
 bool solaris::isLinkerGnuLd(const ToolChain &TC, const ArgList &Args) {
diff --git a/clang/lib/Driver/ToolChains/Solaris.h b/clang/lib/Driver/ToolChains/Solaris.h
index fe3e7f3a1f1b99..04b68c5053caa6 100644
--- a/clang/lib/Driver/ToolChains/Solaris.h
+++ b/clang/lib/Driver/ToolChains/Solaris.h
@@ -19,10 +19,9 @@ namespace tools {
 
 /// solaris -- Directly call Solaris assembler and linker
 namespace solaris {
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler : public gnutools::Assembler {
 public:
-  Assembler(const ToolChain &TC)
-      : Tool("solaris::Assembler", "assembler", TC) {}
+  Assembler(const ToolChain &TC) : gnutools::Assembler(TC) {}
 
   bool hasIntegratedCPP() const override { return false; }
 
diff --git a/clang/test/Driver/solaris-as.c b/clang/test/Driver/solaris-as.c
new file mode 100644
index 00000000000000..bf06dd97cc3862
--- /dev/null
+++ b/clang/test/Driver/solaris-as.c
@@ -0,0 +1,11 @@
+/// General tests for assembler invocations on Solaris.
+
+/// Test that clang uses gas on Solaris.
+// RUN: %clang -x assembler %s -### -c -fno-integrated-as \
+// RUN:         --target=sparc-sun-solaris2.11 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-GAS %s
+// RUN: %clang -x assembler %s -### -c -fno-integrated-as \
+// RUN:         --target=sparc-sun-solaris2.11 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-GAS %s
+/// Allow for both "/usr/bin/gas" (native) and "gas" (cross) forms.
+// CHECK-GAS: gas"