Drop support for LLVM 10 and below (#5202)

It has been 3 years since Dave propose to bump
minimun LLVM version to 11. The CI is ready.
So let's move on.

Closes #3808.

Signed-off-by: Hengqi Chen <[email protected]>

Author: chenhengqi

CMakeLists.txt

@@ -144,7 +144,7 @@ if(NOT PYTHON_ONLY)
 
     # clang is linked as a library, but the library path searching is
     # primitively supported, unlike libLLVM
-    set(CLANG_SEARCH "/opt/local/llvm/lib;/usr/lib/llvm-3.7/lib;${LLVM_LIBRARY_DIRS}")
+    set(CLANG_SEARCH "/opt/local/llvm/lib;${LLVM_LIBRARY_DIRS}")
     find_library(libclangAnalysis NAMES clangAnalysis clang-cpp HINTS ${CLANG_SEARCH})
     find_library(libclangAST NAMES clangAST clang-cpp HINTS ${CLANG_SEARCH})
     find_library(libclangBasic NAMES clangBasic clang-cpp HINTS ${CLANG_SEARCH})

cmake/clang_libs.cmake

@@ -2,7 +2,7 @@ if(ENABLE_LLVM_SHARED)
 set(llvm_libs "LLVM")
 else()
 set(llvm_raw_libs bitwriter bpfcodegen debuginfodwarf irreader linker
-  mcjit objcarcopts option passes lto)
+  mcjit objcarcopts option passes lto bpfasmparser bpfdisassembler)
 if(ENABLE_LLVM_NATIVECODEGEN)
 set(llvm_raw_libs ${llvm_raw_libs} nativecodegen)
 endif()
@@ -18,10 +18,6 @@ list(FIND LLVM_AVAILABLE_LIBS "LLVMFrontendOpenMP" _llvm_frontendOpenMP)
 if (${_llvm_frontendOpenMP} GREATER -1)
   list(APPEND llvm_raw_libs frontendopenmp)
 endif()
-if (${LLVM_PACKAGE_VERSION} VERSION_EQUAL 6 OR ${LLVM_PACKAGE_VERSION} VERSION_GREATER 6)
-  list(APPEND llvm_raw_libs bpfasmparser)
-  list(APPEND llvm_raw_libs bpfdisassembler)
-endif()
 if (${LLVM_PACKAGE_VERSION} VERSION_EQUAL 15 OR ${LLVM_PACKAGE_VERSION} VERSION_GREATER 15)
   list(APPEND llvm_raw_libs windowsdriver)
 endif()
@@ -43,11 +39,8 @@ else()
 set(clang_libs
   ${libclangFrontend}
   ${libclangSerialization}
-  ${libclangDriver})
-
-if (${LLVM_PACKAGE_VERSION} VERSION_EQUAL 8 OR ${LLVM_PACKAGE_VERSION} VERSION_GREATER 8)
-  list(APPEND clang_libs ${libclangASTMatchers})
-endif()
+  ${libclangDriver}
+  ${libclangASTMatchers})
 
 list(APPEND clang_libs
   ${libclangParse}

src/cc/bcc_debug.cc

@@ -127,12 +127,9 @@ void SourceDebugger::dump() {
     errs() << "Debug Error: cannot get register info\n";
     return;
   }
-#if LLVM_VERSION_MAJOR >= 10
+
   MCTargetOptions MCOptions;
   std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, TripleStr, MCOptions));
-#else
-  std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, TripleStr));
-#endif
   if (!MAI) {
     errs() << "Debug Error: cannot get assembly info\n";
     return;
@@ -174,13 +171,7 @@ void SourceDebugger::dump() {
     return;
   }
 
-  // bcc has only one compilation unit
-  // getCompileUnitAtIndex() was gone in llvm 8.0 (https://reviews.llvm.org/D49741)
-#if LLVM_VERSION_MAJOR >= 8
   DWARFCompileUnit *CU = cast<DWARFCompileUnit>(DwarfCtx->getUnitAtIndex(0));
-#else
-  DWARFCompileUnit *CU = DwarfCtx->getCompileUnitAtIndex(0);
-#endif
   if (!CU) {
     errs() << "Debug Error: dwarf context failed to get compile unit\n";
     return;
@@ -202,15 +193,15 @@ void SourceDebugger::dump() {
     uint64_t Size;
     uint8_t *FuncStart = info.start_;
     uint64_t FuncSize = info.size_;
-#if LLVM_VERSION_MAJOR >= 9
+
     auto section = sections_.find(info.section_);
     if (section == sections_.end()) {
       errs() << "Debug Error: no section entry for section " << info.section_
              << '\n';
       return;
     }
     unsigned SectionID = get<2>(section->second);
-#endif
+
     ArrayRef<uint8_t> Data(FuncStart, FuncSize);
     uint32_t CurrentSrcLine = 0;
 
@@ -219,24 +210,15 @@ void SourceDebugger::dump() {
     string src_dbg_str;
     llvm::raw_string_ostream os(src_dbg_str);
     for (uint64_t Index = 0; Index < FuncSize; Index += Size) {
-#if LLVM_VERSION_MAJOR >= 10
       S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index, nulls());
-#else
-      S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index, nulls(),
-                                 nulls());
-#endif
       if (S != MCDisassembler::Success) {
         os << "Debug Error: disassembler failed: " << std::to_string(S) << '\n';
         break;
       } else {
         DILineInfo LineInfo;
 
         LineTable->getFileLineInfoForAddress(
-#if LLVM_VERSION_MAJOR >= 9
             {(uint64_t)FuncStart + Index, SectionID},
-#else
-            (uint64_t)FuncStart + Index,
-#endif
 #if LLVM_VERSION_MAJOR >= 20
             false,
 #endif
@@ -248,11 +230,7 @@ void SourceDebugger::dump() {
                     os);
         os << format("%4" PRIu64 ":", Index >> 3) << '\t';
         dumpBytes(Data.slice(Index, Size), os);
-#if LLVM_VERSION_MAJOR >= 10
         IP->printInst(&Inst, 0, "", *STI, os);
-#else
-        IP->printInst(&Inst, os, "", *STI);
-#endif
         os << '\n';
       }
     }

src/cc/bcc_debug.h

@@ -29,14 +29,6 @@ class SourceDebugger {
         prog_func_info_(prog_func_info),
         mod_src_(mod_src),
         src_dbg_fmap_(src_dbg_fmap) {}
-// Only support dump for llvm 6.x and later.
-//
-// The llvm 5.x, but not earlier versions, also supports create
-// a dwarf context for source debugging based
-// on a set of in-memory sections with slightly different interfaces.
-// FIXME: possibly to support 5.x
-//
-#if LLVM_VERSION_MAJOR >= 6
   void dump();
 
  private:
@@ -47,10 +39,6 @@ class SourceDebugger {
                    uint32_t &CurrentSrcLine, llvm::raw_ostream &os);
   void getDebugSections(
       llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> &DebugSections);
-#else
-  void dump() {
-  }
-#endif
 
  private:
   llvm::Module *mod_;

src/cc/bpf_module.cc

@@ -123,17 +123,10 @@ class MyMemoryManager : public SectionMemoryManager {
       if (!section)
         continue;
 
-#if LLVM_VERSION_MAJOR >= 10
       auto sec_name = section.get()->getName();
       if (!sec_name)
         continue;
-#else
-      llvm::StringRef sec_name_obj;
-      if (!section.get()->getName(sec_name_obj))
-        continue;
 
-      auto sec_name = &sec_name_obj;
-#endif
       info->section_ = sec_name->str();
       info->size_ = ss.second;
     }
@@ -160,11 +153,9 @@ BPFModule::BPFModule(unsigned flags, TableStorage *ts, bool rw_engine_enabled,
   LLVMInitializeBPFTargetMC();
   LLVMInitializeBPFTargetInfo();
   LLVMInitializeBPFAsmPrinter();
-#if LLVM_VERSION_MAJOR >= 6
   LLVMInitializeBPFAsmParser();
   if (flags & DEBUG_SOURCE)
     LLVMInitializeBPFDisassembler();
-#endif
   LLVMLinkInMCJIT(); /* call empty function to force linking of MCJIT */
   if (!ts_) {
     local_ts_ = createSharedTableStorage();
@@ -553,19 +544,12 @@ int BPFModule::finalize() {
       *sections_p;
 
   mod->setTargetTriple("bpf-pc-linux");
-#if LLVM_VERSION_MAJOR >= 11
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
   mod->setDataLayout("e-m:e-p:64:64-i64:64-i128:128-n32:64-S128");
 #else
   mod->setDataLayout("E-m:e-p:64:64-i64:64-i128:128-n32:64-S128");
 #endif
-#else
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-  mod->setDataLayout("e-m:e-p:64:64-i64:64-n32:64-S128");
-#else
-  mod->setDataLayout("E-m:e-p:64:64-i64:64-n32:64-S128");
-#endif
-#endif
+
   sections_p = rw_engine_enabled_ ? &sections_ : &tmp_sections;
 
   string err;

src/cc/frontends/clang/b_frontend_action.cc

@@ -758,11 +758,7 @@ bool ProbeVisitor::IsContextMemberExpr(Expr *E) {
 
 SourceRange
 ProbeVisitor::expansionRange(SourceRange range) {
-#if LLVM_VERSION_MAJOR >= 7
   return rewriter_.getSourceMgr().getExpansionRange(range).getAsRange();
-#else
-  return rewriter_.getSourceMgr().getExpansionRange(range);
-#endif
 }
 
 SourceLocation
@@ -1431,11 +1427,7 @@ bool BTypeVisitor::VisitImplicitCastExpr(ImplicitCastExpr *E) {
 
 SourceRange
 BTypeVisitor::expansionRange(SourceRange range) {
-#if LLVM_VERSION_MAJOR >= 7
   return rewriter_.getSourceMgr().getExpansionRange(range).getAsRange();
-#else
-  return rewriter_.getSourceMgr().getExpansionRange(range);
-#endif
 }
 
 template <unsigned N>
@@ -1454,17 +1446,10 @@ int64_t BTypeVisitor::getFieldValue(VarDecl *Decl, FieldDecl *FDecl, int64_t Ori
   unsigned idx = FDecl->getFieldIndex();
 
   if (auto I = dyn_cast_or_null<InitListExpr>(Decl->getInit())) {
-#if LLVM_VERSION_MAJOR >= 8
     Expr::EvalResult res;
     if (I->getInit(idx)->EvaluateAsInt(res, C)) {
       return res.Val.getInt().getExtValue();
     }
-#else
-    llvm::APSInt res;
-    if (I->getInit(idx)->EvaluateAsInt(res, C)) {
-      return res.getExtValue();
-    }
-#endif
   }
 
   return OrigFValue;
@@ -1871,17 +1856,10 @@ void BFrontendAction::EndSourceFileAction() {
 
   if (flags_ & DEBUG_PREPROCESSOR)
     rewriter_->getEditBuffer(rewriter_->getSourceMgr().getMainFileID()).write(llvm::errs());
-#if LLVM_VERSION_MAJOR >= 9
+
   llvm::raw_string_ostream tmp_os(mod_src_);
   rewriter_->getEditBuffer(rewriter_->getSourceMgr().getMainFileID())
       .write(tmp_os);
-#else
-  if (flags_ & DEBUG_SOURCE) {
-    llvm::raw_string_ostream tmp_os(mod_src_);
-    rewriter_->getEditBuffer(rewriter_->getSourceMgr().getMainFileID())
-        .write(tmp_os);
-  }
-#endif
 
   for (auto func : func_range_) {
     auto f = func.first;

src/cc/frontends/clang/frontend_action_common.h

@@ -15,10 +15,5 @@
  */
 #include <llvm/Config/llvm-config.h>
 
-#if LLVM_VERSION_MAJOR >= 8
 #define GET_BEGINLOC(E)  ((E)->getBeginLoc())
 #define GET_ENDLOC(E)  ((E)->getEndLoc())
-#else
-#define GET_BEGINLOC(E)  ((E)->getLocStart())
-#define GET_ENDLOC(E)    ((E)->getLocEnd())
-#endif

src/cc/frontends/clang/loader.cc

@@ -179,13 +179,7 @@ static int CreateFromArgs(clang::CompilerInvocation &invocation,
                           const llvm::opt::ArgStringList &ccargs,
                           clang::DiagnosticsEngine &diags)
 {
-#if LLVM_VERSION_MAJOR >= 10
   return clang::CompilerInvocation::CreateFromArgs(invocation, ccargs, diags);
-#else
-  return clang::CompilerInvocation::CreateFromArgs(
-              invocation, const_cast<const char **>(ccargs.data()),
-              const_cast<const char **>(ccargs.data()) + ccargs.size(), diags);
-#endif
 }
 
 }
@@ -288,13 +282,10 @@ int ClangLoader::parse(
   vector<string> kflags;
   if (kbuild_helper.get_flags(un.machine, &kflags))
     return -1;
-#if LLVM_VERSION_MAJOR >= 9
+
   flags_cstr.push_back("-g");
   flags_cstr.push_back("-gdwarf-4");
-#else
-  if (flags_ & DEBUG_SOURCE)
-    flags_cstr.push_back("-g");
-#endif
+
   for (auto it = kflags.begin(); it != kflags.end(); ++it)
     flags_cstr.push_back(it->c_str());
 
@@ -416,10 +407,8 @@ int ClangLoader::do_compile(
   string target_triple = get_clang_target();
   driver::Driver drv("", target_triple, diags);
 
-#if LLVM_VERSION_MAJOR >= 4
   if (target_triple == "x86_64-unknown-linux-gnu" || target_triple == "aarch64-unknown-linux-gnu")
     flags_cstr.push_back("-fno-jump-tables");
-#endif
 
   drv.setTitle("bcc-clang-driver");
   drv.setCheckInputsExist(false);