[clang] [lld] [Clang][MinGW] Pass --functionpadmin to the linker when -fms-hotpatch is used (PR #116512)

[Jacek Caban via cfe-commits]

https://github.com/cjacek created https://github.com/llvm/llvm-project/pull/116512

None

>From c13f631c8074c85242fd1f639fd09aae78fede6a Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek at codeweavers.com>
Date: Sat, 16 Nov 2024 14:16:58 +0100
Subject: [PATCH 1/2] [LLD][MinGW] Add support for --functionpadmin option

This introduces the MinGW counterpart of lld-link's -functionpadmin.
---
 lld/MinGW/Driver.cpp       | 8 ++++++++
 lld/MinGW/Options.td       | 3 +++
 lld/test/MinGW/driver.test | 7 +++++++
 3 files changed, 18 insertions(+)

diff --git a/lld/MinGW/Driver.cpp b/lld/MinGW/Driver.cpp
index 553698d4f537fc..706687202b19fb 100644
--- a/lld/MinGW/Driver.cpp
+++ b/lld/MinGW/Driver.cpp
@@ -329,6 +329,14 @@ bool link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
       add("-build-id");
   }
 
+  if (auto *a = args.getLastArg(OPT_functionpadmin)) {
+    StringRef v = a->getValue();
+    if (v.empty())
+      add("-functionpadmin");
+    else
+      add("-functionpadmin:" + v);
+  }
+
   if (args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false))
     add("-WX");
   else
diff --git a/lld/MinGW/Options.td b/lld/MinGW/Options.td
index ff7e21fa808f39..abe5e5c82ca3ff 100644
--- a/lld/MinGW/Options.td
+++ b/lld/MinGW/Options.td
@@ -215,6 +215,9 @@ defm error_limit:
 def build_id: J<"build-id=">, HelpText<"Generate build ID note (pass none to disable)">, 
   MetaVarName<"<arg>">;
 def : F<"build-id">, Alias<build_id>, HelpText<"Alias for --build-id=">;
+def functionpadmin: J<"functionpadmin=">, HelpText<"Prepares an image for hotpatching">,
+  MetaVarName<"<arg>">;
+def : F<"functionpadmin">, Alias<functionpadmin>, HelpText<"Alias for --functionpadmin=">;
 
 // Alias
 def alias_Bdynamic_call_shared: Flag<["-"], "call_shared">, Alias<Bdynamic>;
diff --git a/lld/test/MinGW/driver.test b/lld/test/MinGW/driver.test
index 2831d155fef128..ed6bc880f8f2d9 100644
--- a/lld/test/MinGW/driver.test
+++ b/lld/test/MinGW/driver.test
@@ -445,6 +445,13 @@ RUN: ld.lld -### foo.o -m i386pep --build-id=fast 2>&1 | FileCheck -check-prefix
 BUILD_ID_WARN: unsupported build id hashing: fast, using default hashing.
 BUILD_ID_WARN: -build-id{{ }}
 
+RUN: ld.lld -### foo.o -m i386pep --functionpadmin= 2>&1 | FileCheck -check-prefix=FUNCTIONPADMIN %s
+RUN: ld.lld -### foo.o -m i386pep --functionpadmin 2>&1 | FileCheck -check-prefix=FUNCTIONPADMIN %s
+FUNCTIONPADMIN: -functionpadmin{{ }}
+
+RUN: ld.lld -### foo.o -m i386pep --functionpadmin=2 2>&1 | FileCheck -check-prefix=FUNCTIONPADMIN2 %s
+FUNCTIONPADMIN2: -functionpadmin:2{{ }}
+
 RUN: ld.lld -### foo.o -m i386pep --build-id=none 2>&1 | FileCheck -check-prefix=NO_BUILD_ID %s
 RUN: ld.lld -### foo.o -m i386pep -s 2>&1 | FileCheck -check-prefix=NO_BUILD_ID %s
 RUN: ld.lld -### foo.o -m i386pep -S 2>&1 | FileCheck -check-prefix=NO_BUILD_ID %s

>From 51ebafdc3f6ec6251f042b8a13175f3b017f1833 Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek at codeweavers.com>
Date: Sat, 16 Nov 2024 14:32:55 +0100
Subject: [PATCH 2/2] [clang][MinGW] Pass --functionpadmin to the linker when
 -fms-hotpatch is used

---
 clang/lib/Driver/ToolChains/MinGW.cpp | 3 +++
 clang/test/Driver/mingw.cpp           | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index e51daca5025a80..963de81027ca9f 100644
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -188,6 +188,9 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
           << A->getSpelling() << GuardArgs;
   }
 
+  if (Args.hasArg(options::OPT_fms_hotpatch))
+    CmdArgs.push_back("--functionpadmin");
+
   CmdArgs.push_back("-o");
   const char *OutputFile = Output.getFilename();
   // GCC implicitly adds an .exe extension if it is given an output file name
diff --git a/clang/test/Driver/mingw.cpp b/clang/test/Driver/mingw.cpp
index 4a9ba4d259b46f..9790c86a364f85 100644
--- a/clang/test/Driver/mingw.cpp
+++ b/clang/test/Driver/mingw.cpp
@@ -84,3 +84,7 @@
 // RUN: %clang --target=arm64ec-windows-gnu -### -o /dev/null %s 2>&1 \
 // RUN:   | FileCheck %s --check-prefix CHECK_MINGW_EC_LINK
 // CHECK_MINGW_EC_LINK: "-m" "arm64ecpe"
+
+// RUN: %clang --target=i686-windows-gnu -fms-hotpatch -### -- %s 2>&1 \
+// RUN:    | FileCheck %s --check-prefix=FUNCTIONPADMIN
+// FUNCTIONPADMIN: "--functionpadmin"