[clang] [PS5][Driver] Pass default -z options to PS5 linker (PR #113162)

[Edd Dawson via cfe-commits]

https://github.com/playstation-edd created https://github.com/llvm/llvm-project/pull/113162

Until now, these options have been hardcoded as downstream patches in LLD. Add them to the driver so that the private patches can be removed.

PS5 only. These implementation of these behaviours will remain in the proprietary linker on PS4.

SIE tracker: TOOLCHAIN-16704

>From 0d931fb93485472e2e7263496eb6d2bc71a9ae73 Mon Sep 17 00:00:00 2001
From: Edd Dawson <edd.dawson at sony.com>
Date: Mon, 21 Oct 2024 13:08:31 +0100
Subject: [PATCH] [PS5][Driver] Pass default -z options to PS5 linker

Until now, these options have been hardcoded as downstream patches in
LLD. Add them to the driver so that the private patches can be removed.

PS5 only. These implementation of these behaviours will remain in the
proprietary linker on PS4.

SIE tracker: TOOLCHAIN-16704
---
 clang/lib/Driver/ToolChains/PS4CPU.cpp | 33 ++++++++++++++++++++++----
 clang/test/Driver/ps5-linker.c         | 16 +++++++++++++
 2 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/PS4CPU.cpp b/clang/lib/Driver/ToolChains/PS4CPU.cpp
index 7c028f18c0308f..a6a3501394afae 100644
--- a/clang/lib/Driver/ToolChains/PS4CPU.cpp
+++ b/clang/lib/Driver/ToolChains/PS4CPU.cpp
@@ -229,6 +229,8 @@ void tools::PS5cpu::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   const Driver &D = TC.getDriver();
   ArgStringList CmdArgs;
 
+  const bool Relocatable = Args.hasArg(options::OPT_r);
+
   // Silence warning for "clang -g foo.o -o foo"
   Args.ClaimAllArgs(options::OPT_g_Group);
   // and "clang -emit-llvm foo.o -o foo"
@@ -240,11 +242,32 @@ void tools::PS5cpu::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back(
       Args.MakeArgString("--sysroot=" + TC.getSDKLibraryRootDir()));
 
-  // Default to PIE for non-static executables.
-  const bool PIE =
-      !Args.hasArg(options::OPT_r, options::OPT_shared, options::OPT_static);
-  if (Args.hasFlag(options::OPT_pie, options::OPT_no_pie, PIE))
-    CmdArgs.push_back("-pie");
+  if (!Relocatable) {
+    // Default to PIE for non-static executables.
+    const bool PIE = !Args.hasArg(options::OPT_shared, options::OPT_static);
+    if (Args.hasFlag(options::OPT_pie, options::OPT_no_pie, PIE))
+      CmdArgs.push_back("-pie");
+
+    // Lazy binding of PLTs is not supported on PlayStation. They are placed in
+    // the RelRo segment.
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("now");
+
+    // Don't export linker-generated __start/stop... section bookends.
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("start-stop-visibility=hidden");
+
+    // Patch relocated regions of DWARF whose targets are eliminated at link
+    // time with specific tombstones, such that they're recognisable by the
+    // PlayStation debugger.
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("dead-reloc-in-nonalloc=.debug*=0xffffffffffffffff");
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back(
+        "dead-reloc-in-nonalloc=.debug_ranges=0xfffffffffffffffe");
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("dead-reloc-in-nonalloc=.debug_loc=0xfffffffffffffffe");
+  }
 
   if (Args.hasArg(options::OPT_static))
     CmdArgs.push_back("-static");
diff --git a/clang/test/Driver/ps5-linker.c b/clang/test/Driver/ps5-linker.c
index 4ae65963e361aa..2b9e673c0a23e2 100644
--- a/clang/test/Driver/ps5-linker.c
+++ b/clang/test/Driver/ps5-linker.c
@@ -14,6 +14,22 @@
 // CHECK-NO-PIE-NOT: "-pie"
 // CHECK-SHARED: "--shared"
 
+// Test the driver passes PlayStation-specific -z options to the linker.
+
+// RUN: %clang --target=x86_64-sie-ps5 %s -### 2>&1 | FileCheck --check-prefixes=CHECK-Z %s
+
+// CHECK-Z: {{ld(\.exe)?}}"
+// CHECK-Z-SAME: "-z" "now"
+// CHECK-Z-SAME: "-z" "start-stop-visibility=hidden"
+// CHECK-Z-SAME: "-z" "dead-reloc-in-nonalloc=.debug*=0xffffffffffffffff"
+// CHECK-Z-SAME: "-z" "dead-reloc-in-nonalloc=.debug_ranges=0xfffffffffffffffe"
+// CHECK-Z-SAME: "-z" "dead-reloc-in-nonalloc=.debug_loc=0xfffffffffffffffe"
+
+// RUN: %clang --target=x86_64-sie-ps5 -r %s -### 2>&1 | FileCheck --check-prefixes=CHECK-NO-Z %s
+
+// CHECK-NO-Z: {{ld(\.exe)?}}"
+// CHECK-NO-Z-NOT: "-z"
+
 // Test that -static is forwarded to the linker
 
 // RUN: %clang --target=x86_64-sie-ps5 -static %s -### 2>&1 | FileCheck --check-prefixes=CHECK-STATIC %s