[clang] [Driver] Link Flang runtime on Solaris (PR #65644)

[Rainer Orth via cfe-commits]

https://github.com/rorth created https://github.com/llvm/llvm-project/pull/65644:

I noticed that `flang-new` cannot link Fortran executables on Solaris since the runtime libs are missing.

This patch fixes this, following `Gnu.cpp`.  The `linker-flags.f90` testcase is augmented to test for this.

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

>From 31bdd3477d9f54996b71584598bdd75f2cef31db Mon Sep 17 00:00:00 2001
From: Rainer Orth <ro at gcc.gnu.org>
Date: Thu, 7 Sep 2023 19:19:32 +0200
Subject: [PATCH] [Driver] Link Flang runtime on Solaris

I noticed that `flang-new` cannot link Fortran executables on Solaris since
the runtime libs are missing.

This patch fixes this, following `Gnu.cpp`.  The `linker-flags.f90` testcase
is augmented to test for this.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, and
`x86_64-pc-linux-gnu`.
---
 clang/lib/Driver/ToolChains/Solaris.cpp | 8 ++++++++
 flang/test/Driver/linker-flags.f90      | 1 +
 2 files changed, 9 insertions(+)

diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp
index 36fe12608eefc6c..252c71d3379eab4 100644
--- a/clang/lib/Driver/ToolChains/Solaris.cpp
+++ b/clang/lib/Driver/ToolChains/Solaris.cpp
@@ -223,6 +223,14 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
         getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
       CmdArgs.push_back("-lm");
     }
+    // Additional linker set-up and flags for Fortran. This is required in order
+    // to generate executables. As Fortran runtime depends on the C runtime,
+    // these dependencies need to be listed before the C runtime below.
+    if (D.IsFlangMode()) {
+      addFortranRuntimeLibraryPath(getToolChain(), Args, CmdArgs);
+      addFortranRuntimeLibs(getToolChain(), CmdArgs);
+      CmdArgs.push_back("-lm");
+    }
     if (Args.hasArg(options::OPT_fstack_protector) ||
         Args.hasArg(options::OPT_fstack_protector_strong) ||
         Args.hasArg(options::OPT_fstack_protector_all)) {
diff --git a/flang/test/Driver/linker-flags.f90 b/flang/test/Driver/linker-flags.f90
index 09b8a224df13828..717dcc7775e2126 100644
--- a/flang/test/Driver/linker-flags.f90
+++ b/flang/test/Driver/linker-flags.f90
@@ -4,6 +4,7 @@
 
 ! RUN: %flang -### -target ppc64le-linux-gnu %S/Inputs/hello.f90 2>&1 | FileCheck %s --check-prefixes=CHECK,GNU
 ! RUN: %flang -### -target aarch64-apple-darwin %S/Inputs/hello.f90 2>&1 | FileCheck %s --check-prefixes=CHECK,DARWIN
+! RUN: %flang -### -target sparc-sun-solaris2.11 %S/Inputs/hello.f90 2>&1 | FileCheck %s --check-prefixes=CHECK,GNU
 ! RUN: %flang -### -target x86_64-windows-gnu %S/Inputs/hello.f90 2>&1 | FileCheck %s --check-prefixes=CHECK,MINGW
 
 ! NOTE: Clang's driver library, clangDriver, usually adds 'libcmt' and