sink DebugCompressionType into MC for exposing to clang

This is a preparatory change to expose the debug compression style to
clang.  It requires exposing the enumeration and passing the actual
value through to the backend from the frontend in actual value form
rather than a boolean that selects the GNU style of debug info
compression.

Minor tweak to the ELF Object Writer to use a variable for re-used
values.  Add an assertion that debug information format is one of the
two currently known types if debug information is being compressed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305038 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 12 deletions

diff --git a/tools/llvm-mc/llvm-mc.cpp b/tools/llvm-mc/llvm-mc.cpp
index 87efac2d33c..8782588dfdd 100644
--- a/tools/llvm-mc/llvm-mc.cpp
+++ b/tools/llvm-mc/llvm-mc.cpp
@@ -56,17 +56,15 @@ static cl::opt<bool> RelaxELFRel(
     "relax-relocations", cl::init(true),
     cl::desc("Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL"));
 
-static cl::opt<DebugCompressionType>
-CompressDebugSections("compress-debug-sections", cl::ValueOptional,
-  cl::init(DebugCompressionType::DCT_None),
-  cl::desc("Choose DWARF debug sections compression:"),
-  cl::values(
-    clEnumValN(DebugCompressionType::DCT_None, "none",
-      "No compression"),
-    clEnumValN(DebugCompressionType::DCT_Zlib, "zlib",
-      "Use zlib compression"),
-    clEnumValN(DebugCompressionType::DCT_ZlibGnu, "zlib-gnu",
-      "Use zlib-gnu compression (deprecated)")));
+static cl::opt<DebugCompressionType> CompressDebugSections(
+    "compress-debug-sections", cl::ValueOptional,
+    cl::init(DebugCompressionType::None),
+    cl::desc("Choose DWARF debug sections compression:"),
+    cl::values(clEnumValN(DebugCompressionType::None, "none", "No compression"),
+               clEnumValN(DebugCompressionType::Z, "zlib",
+                          "Use zlib compression"),
+               clEnumValN(DebugCompressionType::GNU, "zlib-gnu",
+                          "Use zlib-gnu compression (deprecated)")));
 
 static cl::opt<bool>
 ShowInst("show-inst", cl::desc("Show internal instruction representation"));
@@ -494,7 +492,7 @@ int main(int argc, char **argv) {
 
   MAI->setRelaxELFRelocations(RelaxELFRel);
 
-  if (CompressDebugSections != DebugCompressionType::DCT_None) {
+  if (CompressDebugSections != DebugCompressionType::None) {
     if (!zlib::isAvailable()) {
       errs() << ProgName
              << ": build tools with zlib to enable -compress-debug-sections";