Add AsmParser support for the ELF .previous directive. Patch by Roman Divacky.

llvm-svn: 112849

5 files changed, 15 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 4ededb24fdc..1cc8fb0b548 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -217,6 +217,7 @@ static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
 void MCAsmStreamer::SwitchSection(const MCSection *Section) {
   assert(Section && "Cannot switch to a null section!");
   if (Section != CurSection) {
+    PrevSection = CurSection;
     CurSection = Section;
     Section->PrintSwitchToSection(MAI, OS);
   }
diff --git a/llvm/lib/MC/MCNullStreamer.cpp b/llvm/lib/MC/MCNullStreamer.cpp
index 5332ade2115..f7a2f20ca4b 100644
--- a/llvm/lib/MC/MCNullStreamer.cpp
+++ b/llvm/lib/MC/MCNullStreamer.cpp
@@ -26,6 +26,7 @@ namespace {
     /// @{
 
     virtual void SwitchSection(const MCSection *Section) {
+      PrevSection = CurSection;
       CurSection = Section;
     }
 
diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index eed4e7bd4f6..2b2385ef915 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -77,6 +77,7 @@ void MCObjectStreamer::SwitchSection(const MCSection *Section) {
   // If already in this section, then this is a noop.
   if (Section == CurSection) return;
 
+  PrevSection = CurSection;
   CurSection = Section;
   CurSectionData = &getAssembler().getOrCreateSectionData(*Section);
 }
diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
index b0bc5c6114e..f982fdaecb1 100644
--- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -50,6 +50,7 @@ public:
     AddDirectiveHandler<&ELFAsmParser::ParseDirectiveSize>(".size");
     AddDirectiveHandler<&ELFAsmParser::ParseDirectiveLEB128>(".sleb128");
     AddDirectiveHandler<&ELFAsmParser::ParseDirectiveLEB128>(".uleb128");
+    AddDirectiveHandler<&ELFAsmParser::ParseDirectivePrevious>(".previous");
   }
 
   bool ParseSectionDirectiveData(StringRef, SMLoc) {
@@ -111,6 +112,7 @@ public:
   bool ParseDirectiveLEB128(StringRef, SMLoc);
   bool ParseDirectiveSection(StringRef, SMLoc);
   bool ParseDirectiveSize(StringRef, SMLoc);
+  bool ParseDirectivePrevious(StringRef, SMLoc);
 };
 
 }
@@ -272,6 +274,14 @@ bool ELFAsmParser::ParseDirectiveLEB128(StringRef DirName, SMLoc) {
   return TokError("LEB128 not supported yet");
 }
 
+bool ELFAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
+  const MCSection *PreviousSection = getStreamer().getPreviousSection();
+  if (PreviousSection != NULL)
+    getStreamer().SwitchSection(PreviousSection);
+
+  return false;
+}
+
 namespace llvm {
 
 MCAsmParserExtension *createELFAsmParser() {
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index f682721b4a1..3e9d02ea5ae 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -15,7 +15,8 @@
 #include <cstdlib>
 using namespace llvm;
 
-MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0) {
+MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0),
+                                         PrevSection(0) {
 }
 
 MCStreamer::~MCStreamer() {