Remove "JumpTableDataSection" from TAI, instead, have AsmPrinter

compute it based on what it knows.  As part of this, rename getSectionForMergeableConstant
to getSectionForConstant because it works for non-mergable constants also.

The only functionality change from this is that Xcore will start dropping
its jump tables into readonly section instead of data section in -static mode.
This should be fine as the linker resolves the relocations.  If this is a
problem, let me know and we'll come up with another solution.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77833 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 17 insertions, 13 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 7c9fcf5fd6..f9839ddc68 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -349,8 +349,7 @@ void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
     }
     }
 
-    const MCSection *S =
-      getObjFileLowering().getSectionForMergeableConstant(Kind);
+    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
     
     // The number of sections are small, just do a linear search from the
     // last section to the first.
@@ -419,22 +418,21 @@ void AsmPrinter::EmitJumpTableInfo(MachineJumpTableInfo *MJTI,
   // the appropriate section.
   TargetLowering *LoweringInfo = TM.getTargetLowering();
 
-  const char *JumpTableDataSection = TAI->getJumpTableDataSection();
   const Function *F = MF.getFunction();
-  
-  const MCSection *FuncSection =
-    getObjFileLowering().SectionForGlobal(F, Mang, TM);
-
   bool JTInDiffSection = false;
-  if ((IsPic && !LoweringInfo->usesGlobalOffsetTable()) ||
-      !JumpTableDataSection || F->isWeakForLinker()) {
+  if (F->isWeakForLinker() ||
+      (IsPic && !LoweringInfo->usesGlobalOffsetTable())) {
     // In PIC mode, we need to emit the jump table to the same section as the
     // function body itself, otherwise the label differences won't make sense.
     // We should also do if the section name is NULL or function is declared in
     // discardable section.
-    SwitchToSection(FuncSection);
+    SwitchToSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
   } else {
-    SwitchToDataSection(JumpTableDataSection);
+    // Otherwise, drop it in the readonly section.
+    const MCSection *ReadOnlySection = 
+      getObjFileLowering().getSectionForConstant(
+                                       SectionKind::get(SectionKind::ReadOnly));
+    SwitchToSection(ReadOnlySection);
     JTInDiffSection = true;
   }
   
diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index 1d33c7e1fe..be1e6bfe75 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -178,7 +178,13 @@ void ELFWriter::addExternalSymbol(const char *External) {
 // Get jump table section on the section name returned by TAI
 ELFSection &ELFWriter::getJumpTableSection() {
   unsigned Align = TM.getTargetData()->getPointerABIAlignment();
-  return getSection(TAI->getJumpTableDataSection(),
+  
+  const TargetLoweringObjectFile &TLOF =
+    TM.getTargetLowering()->getObjFileLowering();
+
+  return getSection(TLOF.getSectionForConstant(
+                                      SectionKind::get(SectionKind::ReadOnly))
+                    ->getName(),
                     ELFSection::SHT_PROGBITS,
                     ELFSection::SHF_ALLOC, Align);
 }
@@ -204,7 +210,7 @@ ELFSection &ELFWriter::getConstantPoolSection(MachineConstantPoolEntry &CPE) {
   const TargetLoweringObjectFile &TLOF =
     TM.getTargetLowering()->getObjFileLowering();
 
-  return getSection(TLOF.getSectionForMergeableConstant(Kind)->getName(),
+  return getSection(TLOF.getSectionForConstant(Kind)->getName(),
                     ELFSection::SHT_PROGBITS,
                     ELFSection::SHF_MERGE | ELFSection::SHF_ALLOC,
                     CPE.getAlignment());