[PATCH] D63350: [LLD] [COFF] Handle .eh_frame$symbol as associative comdat for MinGW

[Martin Storsjö via Phabricator via llvm-commits]

mstorsjo created this revision.
mstorsjo added reviewers: rnk, ruiu.
Herald added a project: LLVM.

This matches how it is done for .xdata and .pdata already.

On i386, the symbol name in the section name suffix does not contain the extra underscore prefix.

This is one part of a fix for PR42217.


Repository:
  rLLD LLVM Linker

https://reviews.llvm.org/D63350

Files:
  COFF/InputFiles.cpp
  test/COFF/associative-comdat-mingw-i386.s


Index: test/COFF/associative-comdat-mingw-i386.s
===================================================================
--- /dev/null
+++ test/COFF/associative-comdat-mingw-i386.s
@@ -0,0 +1,37 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=i686-windows-gnu %s -filetype=obj -o %t.obj
+
+# RUN: lld-link -lldmingw -entry:main %t.obj -out:%t.exe
+# RUN: llvm-objdump -s %t.exe | FileCheck %s
+
+# Check that the .eh_frame comdat was included, even if it had no symbols,
+# due to associativity with the symbol _foo.
+
+# CHECK: Contents of section .eh_fram:
+# CHECK:  403000 42
+
+        .text
+        .def            _main;
+        .scl            2;
+        .type           32;
+        .endef
+        .globl          _main
+        .p2align        4, 0x90
+_main:
+        call            _foo
+        ret
+
+        .section        .eh_frame$foo,"dr"
+        .linkonce       discard
+        .byte           0x42
+
+        .def            _foo;
+        .scl            2;
+        .type           32;
+        .endef
+        .section        .text$foo,"xr",discard,foo
+        .globl          _foo
+        .p2align        4
+_foo:
+        ret
Index: COFF/InputFiles.cpp
===================================================================
--- COFF/InputFiles.cpp
+++ COFF/InputFiles.cpp
@@ -288,6 +288,8 @@
   if (SC && SC->getOutputCharacteristics() & IMAGE_SCN_MEM_EXECUTE) {
     StringRef Name;
     COFFObj->getSymbolName(Sym, Name);
+    if (getMachineType() == I386)
+      Name.consume_front("_");
     PrevailingSectionMap[Name] = SectionNumber;
   }
 }
@@ -297,9 +299,10 @@
     const DenseMap<StringRef, uint32_t> &PrevailingSectionMap) {
   StringRef Name;
   COFFObj->getSymbolName(Sym, Name);
-  if (Name.consume_front(".pdata$") || Name.consume_front(".xdata$")) {
-    // For MinGW, treat .[px]data$<func> as implicitly associative to
-    // the symbol <func>.
+  if (Name.consume_front(".pdata$") || Name.consume_front(".xdata$") ||
+      Name.consume_front(".eh_frame$")) {
+    // For MinGW, treat .[px]data$<func> and .eh_frame$<func> as implicitly
+    // associative to the symbol <func>.
     auto ParentSym = PrevailingSectionMap.find(Name);
     if (ParentSym != PrevailingSectionMap.end())
       readAssociativeDefinition(Sym, Def, ParentSym->second);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D63350.204823.patch
Type: text/x-patch
Size: 2292 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190614/b0d65c8f/attachment.bin>