[clang] [Feature]: support for the BC library file into the compile dependencies (PR #119513)

[via cfe-commits]

https://github.com/zhouronghua updated https://github.com/llvm/llvm-project/pull/119513

>From 7c6d2a44b9b0f34aa5b54eb7c4046bb8b15fe6e6 Mon Sep 17 00:00:00 2001
From: "ronghua.zhou" <ronghua.zhou at enflame-tech.com>
Date: Tue, 10 Dec 2024 06:32:24 +0000
Subject: [PATCH] [Feature]: support for the BC library file into the compile
 dependencies

---
 clang/lib/Driver/ToolChains/Clang.cpp   | 44 ++++++++++++++++++++++---
 clang/lib/Frontend/CompilerInstance.cpp | 10 ++++--
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index d3206c3e8e25ed..c51c36adb49ddf 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -996,9 +996,9 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
   else
     ArgM = ArgMD;
 
+  // Determine the output location.
+  const char *DepFile = nullptr;
   if (ArgM) {
-    // Determine the output location.
-    const char *DepFile;
     if (Arg *MF = Args.getLastArg(options::OPT_MF)) {
       DepFile = MF->getValue();
       C.addFailureResultFile(DepFile, &JA);
@@ -1010,8 +1010,9 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
       DepFile = getDependencyFileName(Args, Inputs);
       C.addFailureResultFile(DepFile, &JA);
     }
-    CmdArgs.push_back("-dependency-file");
-    CmdArgs.push_back(DepFile);
+    // mv to dtu select
+    // CmdArgs.push_back("-dependency-file");
+    // CmdArgs.push_back(DepFile);
 
     bool HasTarget = false;
     for (const Arg *A : Args.filtered(options::OPT_MT, options::OPT_MQ)) {
@@ -1100,6 +1101,40 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("__clang_openmp_device_functions.h");
   }
 
+  if (getToolChain().getTriple().isNVPTX() ||
+      getToolChain().getTriple().isAMDGCN()) {
+    //  When we set(CMAKE_DEPFILE_FLAGS_${lang} "-MD -MT <DEP_TARGET> -MF
+    //  <DEP_FILE>.host") in cmake during heterogeneous compilation,
+    // we really gererate *.d.host (for host) and *.d (for GPU target),
+    // the content of *.d  = *.d.host + builtin.bc (i.e. libdevice.10.bc or some
+    // files in --hip-device-lib)
+    // so when libdevice.10.bc or hip-device-lib is updated, the incremental
+    // build rule will be triggered.
+    if (DepFile) {
+      SmallString<128> NewDepFile(DepFile);
+      llvm::StringRef SubStr = ".host";
+      size_t Pos = NewDepFile.find(SubStr);
+      CmdArgs.push_back("-dependency-file");
+      // for tops target, trim .host in dep file
+      if (Pos != llvm::StringRef::npos) {
+        // erase substr
+        auto ndf = NewDepFile.substr(0, Pos);
+        CmdArgs.push_back(Args.MakeArgString(ndf));
+      } else {
+        // if not set dep file with .host extend, remain depfile not touched
+        CmdArgs.push_back(Args.MakeArgString(DepFile));
+      }
+    }
+  }
+  // Host side remain depfile not touched
+  else {
+    // for host compile, we generate orginal dep file
+    if (DepFile) {
+      CmdArgs.push_back("-dependency-file");
+      CmdArgs.push_back(DepFile);
+    }
+  }
+
   if (Args.hasArg(options::OPT_foffload_via_llvm)) {
     // Add llvm_wrappers/* to our system include path.  This lets us wrap
     // standard library headers and other headers.
@@ -1110,7 +1145,6 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
       CmdArgs.push_back("__llvm_offload_device.h");
     else
       CmdArgs.push_back("__llvm_offload_host.h");
-  }
 
   // Add -i* options, and automatically translate to
   // -include-pch/-include-pth for transparent PCH support. It's
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index fbfc305ca06a04..14779b0161a70e 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -494,8 +494,14 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
 
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
-  if (!DepOpts.OutputFile.empty())
-    addDependencyCollector(std::make_shared<DependencyFileGenerator>(DepOpts));
+  if (!DepOpts.OutputFile.empty()) {
+    auto DFG = std::make_shared<DependencyFileGenerator>(DepOpts);
+    for (auto F : getCodeGenOpts().LinkBitcodeFiles) {
+      DFG->maybeAddDependency(F.Filename, false, false, false, false);
+    }
+    addDependencyCollector(DFG);
+  }
+
   if (!DepOpts.DOTOutputFile.empty())
     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
                              getHeaderSearchOpts().Sysroot);