[PS5][Driver] Pass default -z options to PS5 linker

[playstation-edd]

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

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-driver

Author: Edd Dawson (playstation-edd)

Changes

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

---

Full diff: https://github.com/llvm/llvm-project/pull/113162.diff

2 Files Affected:

• (modified) clang/lib/Driver/ToolChains/PS4CPU.cpp (+28-5)
• (modified) clang/test/Driver/ps5-linker.c (+16)

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

[playstation-edd]

@pogo59 - I recall you expressed an interest in being subscribed to such PRs. Please do let me know if it gets tiresome!

[playstation-edd]

Note to self: fix typo in comment on submission ("These implementation ...").

[jmorse]

LGTM

[pogo59]

Did you mean to include these changes in the PR? It looks like the old code would pass through an explicit -pie even with -r; the new code will (probably) diagnose that -pie as unused. This is likely a good thing, but is not mentioned in the commit message.

[playstation-edd]

The inclusion was deliberate. I took the opportunity to perform the check for OPT_r in one place. But I didn't spot the edge-case change in behaviour that you mention, forgetting that hasArg() had a side-effect - sorry!

Would we prefer that I undo this bit and defer to a separate PR? Or update the final commit message and perhaps add a test case for the behaviour change?

[pogo59]

These are small things but I'd be inclined to separate it out. Apart from being "in the driver" it's not really related, functionally, to the -z changes.

[playstation-edd]

I have undone this part of the change. Thanks for spotting it.