[clang] [clang][hexagon] Add support for -nolibc (PR #67515)

[via cfe-commits]

https://github.com/androm3da updated https://github.com/llvm/llvm-project/pull/67515

>From 4048b1e2557b11650cf2fa568c8814716e45daf5 Mon Sep 17 00:00:00 2001
From: Brian Cain <bcain at quicinc.com>
Date: Tue, 26 Sep 2023 19:57:47 -0700
Subject: [PATCH] [clang][hexagon] Add support for -nolibc

---
 clang/lib/Driver/ToolChains/Hexagon.cpp     |  6 ++++--
 clang/test/Driver/hexagon-toolchain-elf.c   | 23 ++++++++++++++++++++-
 clang/test/Driver/hexagon-toolchain-linux.c | 10 +++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Hexagon.cpp b/clang/lib/Driver/ToolChains/Hexagon.cpp
index e7dca1053dc8d8a..d81e022708932f7 100644
--- a/clang/lib/Driver/ToolChains/Hexagon.cpp
+++ b/clang/lib/Driver/ToolChains/Hexagon.cpp
@@ -377,7 +377,8 @@ constructHexagonLinkArgs(Compilation &C, const JobAction &JA,
         linkXRayRuntimeDeps(HTC, Args, CmdArgs);
 
       CmdArgs.push_back("-lclang_rt.builtins-hexagon");
-      CmdArgs.push_back("-lc");
+      if (!Args.hasArg(options::OPT_nolibc))
+        CmdArgs.push_back("-lc");
     }
     if (D.CCCIsCXX()) {
       if (HTC.ShouldLinkCXXStdlib(Args))
@@ -470,7 +471,8 @@ constructHexagonLinkArgs(Compilation &C, const JobAction &JA,
     if (!IsShared) {
       for (StringRef Lib : OsLibs)
         CmdArgs.push_back(Args.MakeArgString("-l" + Lib));
-      CmdArgs.push_back("-lc");
+      if (!Args.hasArg(options::OPT_nolibc))
+        CmdArgs.push_back("-lc");
     }
     CmdArgs.push_back("-lgcc");
 
diff --git a/clang/test/Driver/hexagon-toolchain-elf.c b/clang/test/Driver/hexagon-toolchain-elf.c
index b840de28fd92089..da859a144cfc888 100644
--- a/clang/test/Driver/hexagon-toolchain-elf.c
+++ b/clang/test/Driver/hexagon-toolchain-elf.c
@@ -278,7 +278,7 @@
 // CHECK335-SAME: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/G0/fini.o"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-// -nostdlib, -nostartfiles, -nodefaultlibs
+// -nostdlib, -nostartfiles, -nodefaultlibs, -nolibc
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // RUN: %clangxx -### --target=hexagon-unknown-elf \
 // RUN:   -ccc-install-dir %S/Inputs/hexagon_tree/Tools/bin \
@@ -337,6 +337,27 @@
 // CHECK338-NOT: "--end-group"
 // CHECK338: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/fini.o"
 
+// RUN: %clangxx -### --target=hexagon-unknown-elf \
+// RUN:   -ccc-install-dir %S/Inputs/hexagon_tree/Tools/bin -mcpu=hexagonv60 \
+// RUN:   -fuse-ld=lld -nolibc %s 2>&1 | FileCheck -check-prefix=CHECK-NOLIBC %s
+// CHECK-NOLIBC: "-cc1"
+// CHECK-NOLIBC: ld.lld
+// CHECK-NOLIBC-SAME: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/crt0_standalone.o"
+// CHECK-NOLIBC-SAME: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/crt0.o"
+// CHECK-NOLIBC-SAME: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/init.o"
+// CHECK-NOLIBC-SAME: "-L{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60"
+// CHECK-NOLIBC-SAME: "-L{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib"
+// CHECK-NOLIBC-SAME: "{{[^"]+}}.o"
+// CHECK-NOLIBC-SAME: "-lstdc++"
+// CHECK-NOLIBC-SAME: "-lm"
+// CHECK-NOLIBC-SAME: "--start-group"
+// CHECK-NOLIBC-SAME: "-lstandalone"
+// CHECK-NOLIBC-NOT: "-lc"
+// CHECK-NOLIBC-SAME: "-lgcc"
+// CHECK-NOLIBC-SAME: "--end-group"
+// CHECK-NOLIBC-SAME: "{{.*}}/Inputs/hexagon_tree/Tools/bin/../target/hexagon/lib/v60/fini.o"
+
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // -moslib
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
diff --git a/clang/test/Driver/hexagon-toolchain-linux.c b/clang/test/Driver/hexagon-toolchain-linux.c
index 51aa6ec90dc017b..fe32638417ea4ad 100644
--- a/clang/test/Driver/hexagon-toolchain-linux.c
+++ b/clang/test/Driver/hexagon-toolchain-linux.c
@@ -58,6 +58,16 @@
 // CHECK004-NOT:   "-lclang_rt.builtins-hexagon"
 // CHECK004-NOT:   "-lc"
 // -----------------------------------------------------------------------------
+// Passing --musl -nolibc
+// -----------------------------------------------------------------------------
+// RUN: %clang -### --target=hexagon-unknown-linux-musl \
+// RUN:   -ccc-install-dir %S/Inputs/hexagon_tree/Tools/bin \
+// RUN:   -mcpu=hexagonv60 --sysroot=%S/Inputs/basic_linux_libcxx_tree \
+// RUN:   -nolibc %s 2>&1 | FileCheck -check-prefix=CHECK-NOLIBC %s
+// CHECK-NOLIBC:       "-dynamic-linker={{/|\\\\}}lib{{/|\\\\}}ld-musl-hexagon.so.1"
+// CHECK-NOLIBC-SAME:  "{{.*}}basic_linux_libcxx_tree{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}crt1.o"
+// CHECK-NOLIBC-NOT:   "-lc"
+// -----------------------------------------------------------------------------
 // Not Passing -fno-use-init-array when musl is selected
 // -----------------------------------------------------------------------------
 // RUN: %clang -### --target=hexagon-unknown-linux-musl \