From 1eaf8a5165d55cab4b844ae82c3a952c81023473 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 7 May 2025 00:55:04 -0700
Subject: [PATCH 1/2] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20in?=
 =?UTF-8?q?itial=20version?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Created using spr 1.3.5-bogner
---
 llvm/lib/MC/MCContext.cpp       | 21 +++++++++++++++++++++
 llvm/test/MC/ELF/symbol-names.s | 19 ++++++++++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index f70087e14f702..41caf20b331b2 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -212,6 +212,27 @@ MCDataFragment *MCContext::allocInitialFragment(MCSection &Sec) {
 MCSymbol *MCContext::getOrCreateSymbol(const Twine &Name) {
   SmallString<128> NameSV;
   StringRef NameRef = Name.toStringRef(NameSV);
+  if (NameRef.contains('\\')) {
+    NameSV = NameRef;
+    size_t S = 0;
+    // Support escaped \\ and \" as in GNU Assembler. GAS issues a warning for
+    // other characters following \\, which we do not implement due to code
+    // structure.
+    for (size_t I = 0, E = NameSV.size(); I < E; ++I) {
+      char C = NameSV[I];
+      if (C == '\\') {
+        switch (NameSV[I + 1]) {
+        case '"':
+        case '\\':
+          C = NameSV[++I];
+          break;
+        }
+      }
+      NameSV[S++] = C;
+    }
+    NameSV.resize(S);
+    NameRef = NameSV;
+  }
 
   assert(!NameRef.empty() && "Normal symbols cannot be unnamed!");
 
diff --git a/llvm/test/MC/ELF/symbol-names.s b/llvm/test/MC/ELF/symbol-names.s
index f605c723d4d4d..8c891052ebd9a 100644
--- a/llvm/test/MC/ELF/symbol-names.s
+++ b/llvm/test/MC/ELF/symbol-names.s
@@ -1,12 +1,25 @@
-// RUN: llvm-mc -triple i686-pc-linux -filetype=obj %s -o - | llvm-readobj --symbols - | FileCheck %s
+// RUN: llvm-mc -triple=x86_64 -filetype=obj %s | llvm-objdump -tdr - | FileCheck %s
 
 // MC allows ?'s in symbol names as an extension.
 
+// CHECK-LABEL:SYMBOL TABLE:
+// CHECK-NEXT: 0000000000000001 l     F .text  0000000000000000 a"b\{{$}}
+// CHECK-NEXT: 0000000000000000 g     F .text  0000000000000000 foo?bar
+// CHECK-NEXT: 0000000000000000 *UND*          0000000000000000 a"b\q{{$}}
+// CHECK-EMPTY:
+
 .text
 .globl foo?bar
 .type foo?bar, @function
 foo?bar:
 ret
 
-// CHECK: Symbol
-// CHECK: Name: foo?bar
+// CHECK-LABEL:<a"b\>:
+// CHECK-NEXT:   callq  {{.*}} <a"b\>
+// CHECK-NEXT:   callq  {{.*}}
+// CHECK-NEXT:     R_X86_64_PLT32 a"b\q-0x4
+.type "a\"b\\", @function
+"a\"b\\":
+  call "a\"b\\"
+/// GAS emits a warning for \q
+  call "a\"b\q"

From 688b66793add274fac2aa6877c2d01ccaaa5222a Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 7 May 2025 23:00:29 -0700
Subject: [PATCH 2/2] update safeseh.s

Created using spr 1.3.5-bogner
---
 llvm/lib/MC/MCSymbol.cpp    | 2 ++
 llvm/test/MC/COFF/safeseh.s | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/MC/MCSymbol.cpp b/llvm/lib/MC/MCSymbol.cpp
index 2a709f4aef80c..3ca85b76a35d9 100644
--- a/llvm/lib/MC/MCSymbol.cpp
+++ b/llvm/lib/MC/MCSymbol.cpp
@@ -74,6 +74,8 @@ void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
       OS << "\\n";
     else if (C == '"')
       OS << "\\\"";
+    else if (C == '\\')
+      OS << "\\\\";
     else
       OS << C;
   }
diff --git a/llvm/test/MC/COFF/safeseh.s b/llvm/test/MC/COFF/safeseh.s
index d21628daff5fa..afcdc771ff994 100644
--- a/llvm/test/MC/COFF/safeseh.s
+++ b/llvm/test/MC/COFF/safeseh.s
@@ -2,5 +2,5 @@
 
 // check that we quote the output of .safeseh
 
-.safeseh "\01foo"
-// CHECK: .safeseh "\01foo"
+.safeseh "\\foo"
+// CHECK: .safeseh "\\foo"