[Transforms][RISCV] Remove a "using namespace llvm" from an include file. Fix a place that became dependent on it.

[craig.topper]

Summary

This include file was created in October and has a "using namespace llvm". This seems to get exposed to other include files and finally onto cpp files. While this somewhat okay for llvm itself, its bad for other projects that use llvm as a library and includes a header file that picks this up. This was found by ISPC which has some class names at gloal scope with the same names as LLVM.

It looks like RISCV accidentally became dependent on this. I fixed it by reordering some includes in the RISCV code, but maybe we want to change the TableGenEmitter to put "namespace llvm {" in the generated file instead? But we probably want to do the simplest thing first so we can merge it to 10.0.

[dblaikie]

Ah, bother - good catch!

[hans]

Cherry-picked to 10.x in ac2c2db1674f200f87b05bee528c761600d87615 thanks!

llvm/include/llvm/Transforms/Utils/SizeOpts.h

 
 #ifndef LLVM_TRANSFORMS_UTILS_SIZEOPTS_H
 #define LLVM_TRANSFORMS_UTILS_SIZEOPTS_H
 
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Support/CommandLine.h"
 
-using namespace llvm;
-
-extern cl::opt<bool> EnablePGSO;
-extern cl::opt<bool> PGSOLargeWorkingSetSizeOnly;
-extern cl::opt<bool> PGSOIRPassOrTestOnly;
-extern cl::opt<bool> PGSOColdCodeOnly;
-extern cl::opt<bool> ForcePGSO;
-extern cl::opt<int> PgsoCutoffInstrProf;
-extern cl::opt<int> PgsoCutoffSampleProf;
+extern llvm::cl::opt<bool> EnablePGSO;
+extern llvm::cl::opt<bool> PGSOLargeWorkingSetSizeOnly;
+extern llvm::cl::opt<bool> PGSOIRPassOrTestOnly;
+extern llvm::cl::opt<bool> PGSOColdCodeOnly;
+extern llvm::cl::opt<bool> ForcePGSO;
+extern llvm::cl::opt<int> PgsoCutoffInstrProf;
+extern llvm::cl::opt<int> PgsoCutoffSampleProf;
 
 namespace llvm {
 
 class BasicBlock;
 class BlockFrequencyInfo;
 class Function;
 class ProfileSummaryInfo;
 

llvm/lib/Target/RISCV/RISCVInstrInfo.cpp

 #include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/RegisterScavenging.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TargetRegistry.h"
 
+using namespace llvm;
+
 #define GEN_CHECK_COMPRESS_INSTR
 #include "RISCVGenCompressInstEmitter.inc"
 
 #define GET_INSTRINFO_CTOR_DTOR
 #include "RISCVGenInstrInfo.inc"
 
-using namespace llvm;
-
 RISCVInstrInfo::RISCVInstrInfo(RISCVSubtarget &STI)
     : RISCVGenInstrInfo(RISCV::ADJCALLSTACKDOWN, RISCV::ADJCALLSTACKUP),
       STI(STI) {}
 
 unsigned RISCVInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
                                              int &FrameIndex) const {
   switch (MI.getOpcode()) {
   default: