[LLD][COFF] Emit tail merge pdata for delay load thunks on ARM64EC

[cjacek]

No description provided.

[llvmbot]

@llvm/pr-subscribers-lld
@llvm/pr-subscribers-lld-coff

@llvm/pr-subscribers-platform-windows

Author: Jacek Caban (cjacek)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/116810.diff

2 Files Affected:

• (modified) lld/COFF/DLL.cpp (+4)
• (modified) lld/test/COFF/arm64ec-delayimport.test (+8-5)

diff --git a/lld/COFF/DLL.cpp b/lld/COFF/DLL.cpp
index 797d9f1490253a..0f6a40a41ca00f 100644
--- a/lld/COFF/DLL.cpp
+++ b/lld/COFF/DLL.cpp
@@ -395,6 +395,7 @@ class TailMergePDataChunkX64 : public NonSectionChunk {
   }
 
   size_t getSize() const override { return 3 * sizeof(uint32_t); }
+  MachineTypes getMachine() const override { return AMD64; }
 
   void writeTo(uint8_t *buf) const override {
     write32le(buf + 0, tm->getRVA()); // TailMergeChunk start RVA
@@ -415,6 +416,7 @@ class TailMergeUnwindInfoX64 : public NonSectionChunk {
   }
 
   size_t getSize() const override { return sizeof(tailMergeUnwindInfoX64); }
+  MachineTypes getMachine() const override { return AMD64; }
 
   void writeTo(uint8_t *buf) const override {
     memcpy(buf, tailMergeUnwindInfoX64, sizeof(tailMergeUnwindInfoX64));
@@ -882,6 +884,7 @@ Chunk *DelayLoadContents::newTailMergeChunk(Chunk *dir) {
 Chunk *DelayLoadContents::newTailMergeUnwindInfoChunk() {
   switch (ctx.config.machine) {
   case AMD64:
+  case ARM64EC:
     return make<TailMergeUnwindInfoX64>();
     // FIXME: Add support for other architectures.
   default:
@@ -891,6 +894,7 @@ Chunk *DelayLoadContents::newTailMergeUnwindInfoChunk() {
 Chunk *DelayLoadContents::newTailMergePDataChunk(Chunk *tm, Chunk *unwind) {
   switch (ctx.config.machine) {
   case AMD64:
+  case ARM64EC:
     return make<TailMergePDataChunkX64>(tm, unwind);
     // FIXME: Add support for other architectures.
   default:
diff --git a/lld/test/COFF/arm64ec-delayimport.test b/lld/test/COFF/arm64ec-delayimport.test
index 0c8009362f80e7..1e0bd899ba323d 100644
--- a/lld/test/COFF/arm64ec-delayimport.test
+++ b/lld/test/COFF/arm64ec-delayimport.test
@@ -12,9 +12,9 @@ RUN: lld-link -machine:arm64ec -dll -noentry -out:out.dll loadconfig-arm64ec.obj
 RUN:          helper-mangled.obj test-arm64ec.lib test2-arm64ec.lib -delayload:test.dll -map
 
 RUN: llvm-readobj --hex-dump=.test out.dll | FileCheck --check-prefix=TESTSEC %s
-TESTSEC:      0x180009000 00600000 88700000 00200000 10100000
-TESTSEC-NEXT: 0x180009010 08600000 90700000 10200000 30100000
-TESTSEC-NEXT: 0x180009020 1c100000 3c100000 00300000
+TESTSEC:      0x18000a000 00600000 88700000 00200000 10100000
+TESTSEC-NEXT: 0x18000a010 08600000 90700000 10200000 30100000
+TESTSEC-NEXT: 0x18000a020 1c100000 3c100000 00300000
 
 RUN: llvm-objdump -d out.dll | FileCheck --check-prefix=DISASM %s
 DISASM:      0000000180001000 <.text>:
@@ -61,7 +61,7 @@ DISASM-NEXT: 18000203d: 66 0f 7f 4c 24 10            movdqa  %xmm1, 0x10(%rsp)
 DISASM-NEXT: 180002043: 66 0f 7f 54 24 20            movdqa  %xmm2, 0x20(%rsp)
 DISASM-NEXT: 180002049: 66 0f 7f 5c 24 30            movdqa  %xmm3, 0x30(%rsp)
 DISASM-NEXT: 18000204f: 48 8b d0                     movq    %rax, %rdx
-DISASM-NEXT: 180002052: 48 8d 0d 97 21 00 00         leaq    0x2197(%rip), %rcx      # 0x1800041f0
+DISASM-NEXT: 180002052: 48 8d 0d a7 21 00 00         leaq    0x21a7(%rip), %rcx      # 0x180004200
 DISASM-NEXT: 180002059: e8 aa ef ff ff               callq   0x180001008 <.text+0x8>
 DISASM-NEXT: 18000205e: 66 0f 6f 04 24               movdqa  (%rsp), %xmm0
 DISASM-NEXT: 180002063: 66 0f 6f 4c 24 10            movdqa  0x10(%rsp), %xmm1
@@ -85,7 +85,7 @@ IMPORTS-NEXT:   Name: test.dll
 IMPORTS-NEXT:   Attributes: 0x1
 IMPORTS-NEXT:   ModuleHandle: 0x7080
 IMPORTS-NEXT:   ImportAddressTable: 0x7088
-IMPORTS-NEXT:   ImportNameTable: 0x4230
+IMPORTS-NEXT:   ImportNameTable: 0x4240
 IMPORTS-NEXT:   BoundDelayImportTable: 0x0
 IMPORTS-NEXT:   UnloadDelayImportTable: 0x0
 IMPORTS-NEXT:   Import {
@@ -140,6 +140,9 @@ RELOC-NEXT:     Type: DIR64
 RELOC-NEXT:     Address: 0x6008
 RELOC-NEXT:   }
 
+RUN: llvm-readobj --hex-dump=.pdata out.dll | FileCheck --check-prefix=PDATA %s
+PDATA: 0x180008000 2e200000 81200000 18400000
+
 Verify that a demangled version of __delayLoadHelper2 can be used.
 
 RUN: lld-link -machine:arm64ec -dll -noentry -out:out2.dll loadconfig-arm64ec.obj test.obj \

[mstorsjo]

LGTM, looks reasonable and straightforward.

[mstorsjo]

Why is this bit needed here (and the other addition of getMachine() as well), or more precisely - why wasn't it needed before and why is it needed now?

[cjacek]

ARM64EC targets require an additional operation in Writer::mergeSections to separate ARM and x86 chunks. Other targets do not consider the machine type of .pdata entries, so this was unnecessary prior to this PR.

I added getMachine to TailMergeUnwindInfoX64 for consistency, though it could be skipped.