Revert "Revert r305164/5/7."

Restore the `-gz` option to the driver with some minor tweaks to handle
the additional case for `-Wa,--compress-debug-sections`.

This intends to make the compression of the debug information
controllable from the driver.  The following is the behaviour:

  -gz           enable compression (ambiguous for format, will default to zlib-gnu)
  -gz=none      disable compression
  -gz=zlib-gnu  enable compression (deprecated GNU style zlib compression)
  -gz=zlib      enable compression (zlib based compression)

Although -Wa,-compress-debug-sections works, it should be discouraged
when using the driver to invoke the assembler.  However, we permit the
assembler to accept the GNU as style argument --compress-debug-sections
to maintain compatibility.

Note, -gz/-gz= does *NOT* imply -g.  That is, you need to additionally
specific -g for debug information to be generated.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306115 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 59 insertions, 15 deletions

diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index bd4e894d65..292cf72b56 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -910,6 +910,37 @@ static void RenderDebugEnablingArgs(const ArgList &Args, ArgStringList &CmdArgs,
   }
 }
 
+static void RenderDebugInfoCompressionArgs(const ArgList &Args,
+                                           ArgStringList &CmdArgs,
+                                           const Driver &D) {
+  const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ);
+  if (!A)
+    return;
+
+  if (A->getOption().getID() == options::OPT_gz) {
+    if (llvm::zlib::isAvailable())
+      CmdArgs.push_back("-compress-debug-sections");
+    else
+      D.Diag(diag::warn_debug_compression_unavailable);
+    return;
+  }
+
+  StringRef Value = A->getValue();
+  if (Value == "none") {
+    CmdArgs.push_back("-compress-debug-sections=none");
+  } else if (Value == "zlib" || Value == "zlib-gnu") {
+    if (llvm::zlib::isAvailable()) {
+      CmdArgs.push_back(
+          Args.MakeArgString("-compress-debug-sections=" + Twine(Value)));
+    } else {
+      D.Diag(diag::warn_debug_compression_unavailable);
+    }
+  } else {
+    D.Diag(diag::err_drv_unsupported_option_argument)
+        << A->getOption().getName() << Value;
+  }
+}
+
 static const char *RelocationModelName(llvm::Reloc::Model Model) {
   switch (Model) {
   case llvm::Reloc::Static:
@@ -1747,10 +1778,6 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
   // arg after parsing the '-I' arg.
   bool TakeNextArg = false;
 
-  // When using an integrated assembler, translate -Wa, and -Xassembler
-  // options.
-  bool CompressDebugSections = false;
-
   bool UseRelaxRelocations = ENABLE_X86_RELAX_RELOCATIONS;
   const char *MipsTargetFeature = nullptr;
   for (const Arg *A :
@@ -1825,12 +1852,11 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
         CmdArgs.push_back("-massembler-fatal-warnings");
       } else if (Value == "--noexecstack") {
         CmdArgs.push_back("-mnoexecstack");
-      } else if (Value == "-compress-debug-sections" ||
-                 Value == "--compress-debug-sections") {
-        CompressDebugSections = true;
-      } else if (Value == "-nocompress-debug-sections" ||
+      } else if (Value.startswith("-compress-debug-sections") ||
+                 Value.startswith("--compress-debug-sections") ||
+                 Value == "-nocompress-debug-sections" ||
                  Value == "--nocompress-debug-sections") {
-        CompressDebugSections = false;
+        CmdArgs.push_back(Value.data());
       } else if (Value == "-mrelax-relocations=yes" ||
                  Value == "--mrelax-relocations=yes") {
         UseRelaxRelocations = true;
@@ -1883,12 +1909,6 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
       }
     }
   }
-  if (CompressDebugSections) {
-    if (llvm::zlib::isAvailable())
-      CmdArgs.push_back("-compress-debug-sections");
-    else
-      D.Diag(diag::warn_debug_compression_unavailable);
-  }
   if (UseRelaxRelocations)
     CmdArgs.push_back("--mrelax-relocations");
   if (MipsTargetFeature != nullptr) {
@@ -2824,6 +2844,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-generate-type-units");
   }
 
+  RenderDebugInfoCompressionArgs(Args, CmdArgs, D);
+
   bool UseSeparateSections = isUseSeparateSections(Triple);
 
   if (Args.hasFlag(options::OPT_ffunction_sections,
@@ -4927,6 +4949,7 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
 
   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
   const std::string &TripleStr = Triple.getTriple();
+  const auto &D = getToolChain().getDriver();
 
   // Don't warn about "clang -w -c foo.s"
   Args.ClaimAllArgs(options::OPT_w);
@@ -5014,6 +5037,8 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
   }
   RenderDebugEnablingArgs(Args, CmdArgs, DebugInfoKind, DwarfVersion,
                           llvm::DebuggerKind::Default);
+  RenderDebugInfoCompressionArgs(Args, CmdArgs, D);
+
 
   // Handle -fPIC et al -- the relocation-model affects the assembler
   // for some targets.
diff --git a/lib/Driver/ToolChains/Gnu.cpp b/lib/Driver/ToolChains/Gnu.cpp
index d50f8e21f6..c9d15ea00d 100644
--- a/lib/Driver/ToolChains/Gnu.cpp
+++ b/lib/Driver/ToolChains/Gnu.cpp
@@ -650,6 +650,8 @@ void tools::gnutools::Assembler::ConstructJob(Compilation &C,
                                               const InputInfoList &Inputs,
                                               const ArgList &Args,
                                               const char *LinkingOutput) const {
+  const auto &D = getToolChain().getDriver();
+
   claimNoWarnArgs(Args);
 
   ArgStringList CmdArgs;
@@ -660,6 +662,23 @@ void tools::gnutools::Assembler::ConstructJob(Compilation &C,
   std::tie(RelocationModel, PICLevel, IsPIE) =
       ParsePICArgs(getToolChain(), Args);
 
+  if (const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ)) {
+    if (A->getOption().getID() == options::OPT_gz) {
+      CmdArgs.push_back("-compress-debug-sections");
+    } else {
+      StringRef Value = A->getValue();
+      if (Value == "none") {
+        CmdArgs.push_back("-compress-debug-sections=none");
+      } else if (Value == "zlib" || Value == "zlib-gnu") {
+        CmdArgs.push_back(
+            Args.MakeArgString("-compress-debug-sections=" + Twine(Value)));
+      } else {
+        D.Diag(diag::err_drv_unsupported_option_argument)
+            << A->getOption().getName() << Value;
+      }
+    }
+  }
+
   switch (getToolChain().getArch()) {
   default:
     break;