Add TableGen ctags(1) emitter and helper script.

To use this in conjunction with exuberant ctags to generate a single
combined tags file, run tblgen first and then
  $ ctags --append [...]

Since some identifiers have corresponding definitions in C++ code,
it can be useful (if using vim) to also use cscope, and
  :set cscopetagorder=1
so that
  :tag X
will preferentially select the tablegen symbol, while
  :cscope find g X
will always find the C++ symbol.

Patch by Kevin Schoedel!

(a couple small formatting changes courtesy of clang-format)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177682 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 561 insertions, 1 deletions

diff --git a/utils/TableGen/CMakeLists.txt b/utils/TableGen/CMakeLists.txt
index d0f44be69a..3ee1974431 100644
--- a/utils/TableGen/CMakeLists.txt
+++ b/utils/TableGen/CMakeLists.txt
@@ -33,4 +33,5 @@ add_tablegen(llvm-tblgen LLVM
   X86DisassemblerTables.cpp
   X86ModRMFilters.cpp
   X86RecognizableInstr.cpp
+  CTagsEmitter.cpp
   )
diff --git a/utils/TableGen/CTagsEmitter.cpp b/utils/TableGen/CTagsEmitter.cpp
new file mode 100644
index 0000000000..8bf777839b
--- /dev/null
+++ b/utils/TableGen/CTagsEmitter.cpp
@@ -0,0 +1,99 @@
+//===- CTagsEmitter.cpp - Generate ctags-compatible index ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tablegen backend emits an index of definitions in ctags(1) format.
+// A helper script, utils/TableGen/tdtags, provides an easier-to-use
+// interface; run 'tdtags -H' for documentation.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "ctags-emitter"
+
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/TableGen/Error.h"
+#include "llvm/TableGen/Record.h"
+#include "llvm/TableGen/TableGenBackend.h"
+#include <algorithm>
+#include <string>
+#include <vector>
+using namespace llvm;
+
+namespace llvm { extern SourceMgr SrcMgr; }
+
+namespace {
+
+class Tag {
+private:
+  const std::string *Id;
+  SMLoc Loc;
+public:
+  Tag(const std::string &Name, const SMLoc Location)
+      : Id(&Name), Loc(Location) {}
+  int operator<(const Tag &B) const { return *Id < *B.Id; }
+  void emit(raw_ostream &OS) const {
+    int BufferID = SrcMgr.FindBufferContainingLoc(Loc);
+    MemoryBuffer *CurMB = SrcMgr.getBufferInfo(BufferID).Buffer;
+    const char *BufferName = CurMB->getBufferIdentifier();
+    std::pair<unsigned, unsigned> LineAndColumn = SrcMgr.getLineAndColumn(Loc);
+    OS << *Id << "\t" << BufferName << "\t" << LineAndColumn.first << "\n";
+  }
+};
+
+class CTagsEmitter {
+private:
+  RecordKeeper &Records;
+public:
+  CTagsEmitter(RecordKeeper &R) : Records(R) {}
+
+  void run(raw_ostream &OS);
+
+private:
+  static SMLoc locate(const Record *R);
+};
+
+} // End anonymous namespace.
+
+SMLoc CTagsEmitter::locate(const Record *R) {
+  ArrayRef<SMLoc> Locs = R->getLoc();
+  if (Locs.empty()) {
+    SMLoc NullLoc;
+    return NullLoc;
+  }
+  return Locs.front();
+}
+
+void CTagsEmitter::run(raw_ostream &OS) {
+  const std::map<std::string, Record *> &Classes = Records.getClasses();
+  const std::map<std::string, Record *> &Defs = Records.getDefs();
+  std::vector<Tag> Tags;
+  // Collect tags.
+  Tags.reserve(Classes.size() + Defs.size());
+  for (std::map<std::string, Record *>::const_iterator I = Classes.begin(),
+                                                       E = Classes.end();
+       I != E; ++I)
+    Tags.push_back(Tag(I->first, locate(I->second)));
+  for (std::map<std::string, Record *>::const_iterator I = Defs.begin(),
+                                                       E = Defs.end();
+       I != E; ++I)
+    Tags.push_back(Tag(I->first, locate(I->second)));
+  // Emit tags.
+  std::sort(Tags.begin(), Tags.end());
+  OS << "!_TAG_FILE_FORMAT\t1\t/original ctags format/\n";
+  OS << "!_TAG_FILE_SORTED\t1\t/0=unsorted, 1=sorted, 2=foldcase/\n";
+  for (std::vector<Tag>::const_iterator I = Tags.begin(), E = Tags.end();
+       I != E; ++I)
+    I->emit(OS);
+}
+
+namespace llvm {
+
+void EmitCTags(RecordKeeper &RK, raw_ostream &OS) { CTagsEmitter(RK).run(OS); }
+
+} // End llvm namespace.
diff --git a/utils/TableGen/TableGen.cpp b/utils/TableGen/TableGen.cpp
index 510f2548cd..b5c3ca760d 100644
--- a/utils/TableGen/TableGen.cpp
+++ b/utils/TableGen/TableGen.cpp
@@ -40,7 +40,8 @@ enum ActionType {
   GenTgtIntrinsic,
   PrintEnums,
   PrintSets,
-  GenOptParserDefs
+  GenOptParserDefs,
+  GenCTags
 };
 
 namespace {
@@ -82,6 +83,8 @@ namespace {
                                "Print expanded sets for testing DAG exprs"),
                     clEnumValN(GenOptParserDefs, "gen-opt-parser-defs",
                                "Generate option definitions"),
+                    clEnumValN(GenCTags, "gen-ctags",
+                               "Generate ctags-compatible index"),
                     clEnumValEnd));
 
   cl::opt<std::string>
@@ -161,6 +164,9 @@ bool LLVMTableGenMain(raw_ostream &OS, RecordKeeper &Records) {
     }
     break;
   }
+  case GenCTags:
+    EmitCTags(Records, OS);
+    break;
   }
 
   return false;
diff --git a/utils/TableGen/TableGenBackends.h b/utils/TableGen/TableGenBackends.h
index cc99092658..28b626e17e 100644
--- a/utils/TableGen/TableGenBackends.h
+++ b/utils/TableGen/TableGenBackends.h
@@ -75,5 +75,6 @@ void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS);
 void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS);
 void EmitMapTable(RecordKeeper &RK, raw_ostream &OS);
 void EmitOptParser(RecordKeeper &RK, raw_ostream &OS);
+void EmitCTags(RecordKeeper &RK, raw_ostream &OS);
 
 } // End llvm namespace
diff --git a/utils/TableGen/tdtags b/utils/TableGen/tdtags
new file mode 100644
index 0000000000..5214485f4e
--- /dev/null
+++ b/utils/TableGen/tdtags
@@ -0,0 +1,453 @@
+#!/bin/sh
+#===-- tdtags - TableGen tags wrapper ---------------------------*- sh -*-===#
+# vim:set sts=2 sw=2 et:
+#===----------------------------------------------------------------------===#
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===----------------------------------------------------------------------===#
+#
+# This is a wrapper script to simplify generating ctags(1)-compatible index
+# files for target .td files. Run tdtags -H for more documentation.
+#
+# For portability, this script is intended to conform to IEEE Std 1003.1-2008.
+#
+#===----------------------------------------------------------------------===#
+
+SELF=${0##*/}
+
+usage() {
+cat <<END
+Usage: $SELF [ <options> ] tdfile
+   or: $SELF [ <options> ] -x recipe [arg ...]
+OPTIONS
+  -H          Display further help.
+  -a          Append the tags to an existing tags file.
+  -f <file>   Write tags to the specified file (defaults to 'tags').
+  -I <dir>    Add the directory to the search path for tblgen include files.
+  -x <recipe> Generate tags file(s) for a common use case:
+  -q          Suppress $TBLGEN error messages.
+  -v          Be verbose; report progress.
+END
+  usage_recipes
+}
+
+usage_recipes() {
+cat <<END
+     all      - Generate an index in each directory that contains .td files
+                in the LLVM source tree.
+     here     - Generate an index for all .td files in the current directory.
+     recurse  - Generate an index in each directory that contains .td files
+                in and under the current directory.
+     target [<target> ...]
+              - Generate a tags file for each specified LLVM code generator
+                target, or if none are specified, all targets.
+END
+}
+
+help() {
+cat <<END
+NAME
+  $SELF - generate ctags(1)-compatible index files for tblgen .td source
+
+SYNOPSIS
+  $SELF [ options ] -x recipe [arg ...]
+  $SELF [ options ] [file ...]
+
+DESCRIPTION
+  With the '-x' option, $SELF produces one or more tags files for a
+  particular common use case. See the RECIPES section below for details.
+
+  Without the '-x' option, $SELF provides a ctags(1)-like interface to
+  $TBLGEN.
+
+OPTIONS
+  -a          Append newly generated tags to those already in an existing
+              tags file. Without ths option, any and all existing tags are
+              replaced. NOTE: When building a mixed tags file, using ${SELF}
+              for tblgen tags and ctags(1) for other languages, it is best
+              to run ${SELF} first without '-a', and ctags(1) second with '-a',
+              because ctags(1) handling is more capable.
+  -f <file>   Use the name <file> for the tags file, rather than the default
+              "tags". If the <file> is "-", then the tag index is written to
+              standard output.
+  -H          Display this document.
+  -I <dir>    Add the directory <dir> to the search path for 'include'
+              statements in tblgen source.
+  -x          Run a canned recipe, rather than operate on specified files.
+              When '-x' is present, the first non-option argument is the
+              name of a recipe, and any further arguments are arguments to
+              that recipe. With no arguments, lists the available recipes.
+  -q          Suppress $TBLGEN error messages. Not all .td files are well-
+              formed outside a specific context, so recipes will sometimes
+              produce error messages for certain .td files. These errors
+              do not affect the indices produced for valid files.
+  -v          Be verbose; report progress.
+
+RECIPES
+  $SELF -x all
+              Produce a tags file in every directory in the LLVM source tree
+              that contains any .td files.
+  $SELF -x here
+              Produce a tags file from .td files in the current directory.
+  $SELF -x recurse
+              Produce a tags file in every directory that contains any .td
+              files, in and under the current directory.
+  $SELF -x target [<target> ...]
+              Produce a tags file for each named code generator target, or
+              if none are named, for all code generator targets.
+END
+}
+
+# Temporary file management.
+#
+# Since SUS sh(1) has no arrays, this script makes extensive use of
+# temporary files. The follow are 'global' and used to carry information
+# across functions:
+#   $TMP:D    Include directories.
+#   $TMP:I    Included files.
+#   $TMP:T    Top-level files, that are not included by another.
+#   $TMP:W    Directories in which to generate tags (Worklist).
+# For portability to OS X, names must not differ only in case.
+#
+TMP=${TMPDIR:-/tmp}/$SELF:$$
+trap "rm -f $TMP*" 0
+trap exit 1 2 13 15
+>$TMP:D
+
+td_dump()
+{
+  if [ $OPT_VERBOSE -gt 1 ]
+  then
+    printf '===== %s =====\n' "$1"
+    cat <"$1"
+  fi
+}
+
+# Escape the arguments, taken as a whole.
+e() {
+  printf '%s' "$*" |
+    sed -e "s/'/'\\\\''/g" -e "1s/^/'/" -e "\$s/\$/'/"
+}
+
+# Determine whether the given directory contains at least one .td file.
+dir_has_td() {
+  for i in $1/*.td
+  do
+    [ -f "$i" ] && return 0
+  done
+  return 1
+}
+
+# Partition the supplied list of files, plus any files included from them,
+# into two groups:
+#   $TMP:T    Top-level files, that are not included by another.
+#   $TMP:I    Included files.
+# Add standard directories to the include paths in $TMP:D if this would
+# benefit the any of the included files.
+td_prep() {
+  >$TMP:E
+  >$TMP:J
+  for i in *.td
+  do
+    [ "x$i" = 'x*.td' ] && return 1
+    if [ -f "$i" ]
+    then
+      printf '%s\n' "$i" >>$TMP:E
+      sed -n -e 's/include[[:space:]]"\(.*\)".*/\1/p' <"$i" >>$TMP:J
+    else
+      printf >&2 '%s: "%s" not found.\n' "$SELF" "$i"
+      exit 7
+    fi
+  done
+  sort -u <$TMP:E >$TMP:X
+  sort -u <$TMP:J >$TMP:I
+  # A file that exists but is not included is toplevel.
+  comm -23 $TMP:X $TMP:I >$TMP:T
+  td_dump $TMP:T
+  td_dump $TMP:I
+  # Check include files.
+  while read i
+  do
+    [ -f "$i" ] && continue
+    while read d
+    do
+      [ -f "$d/$i" ] && break
+    done <$TMP:D
+    if [ -z "$d" ]
+    then
+      # See whether this include file can be found in a common location.
+      for d in $LLVM_SRC_ROOT/include \
+               $LLVM_SRC_ROOT/tools/clang/include
+      do
+        if [ -f "$d/$i" ]
+        then
+          printf '%s\n' "$d" >>$TMP:D
+          break
+        fi
+      done
+    fi
+  done <$TMP:I
+  td_dump $TMP:D
+}
+
+# Generate tags for the list of files in $TMP:T.
+td_tag() {
+  # Collect include directories.
+  inc=
+  while read d
+  do
+    inc="${inc}${inc:+ }$(e "-I=$d")"
+  done <$TMP:D
+
+  if [ $OPT_VERBOSE -ne 0 ]
+  then
+    printf >&2 'In "%s",\n' "$PWD"
+  fi
+
+  # Generate tags for each file.
+  n=0
+  while read i
+  do
+    if [ $OPT_VERBOSE -ne 0 ]
+    then
+      printf >&2 '  generating tags from "%s"\n' "$i"
+    fi
+    n=$((n + 1))
+    t=$(printf '%s:A:%05u' "$TMP" $n)
+    eval $TBLGEN --gen-ctags $inc "$i" >$t 2>$TMP:F
+    [ $OPT_NOTBLGENERR -eq 1 ] || cat $TMP:F
+  done <$TMP:T
+
+  # Add existing tags if requested.
+  if [ $OPT_APPEND -eq 1 -a -f "$OPT_TAGSFILE" ]
+  then
+    if [ $OPT_VERBOSE -ne 0 ]
+    then
+      printf >&2 '  and existing tags from "%s"\n' "$OPT_TAGSFILE"
+    fi
+    n=$((n + 1))
+    t=$(printf '%s:A:%05u' "$TMP" $n)
+    sed -e '/^!_TAG_/d' <"$OPT_TAGSFILE" | sort -u >$t
+  fi
+
+  # Merge tags.
+  if [ $n = 1 ]
+  then
+    mv -f "$t" $TMP:M
+  else
+    sort -m -u $TMP:A:* >$TMP:M
+  fi
+
+  # Emit tags.
+  if [ x${OPT_TAGSFILE}x = x-x ]
+  then
+    cat $TMP:M
+  else
+    if [ $OPT_VERBOSE -ne 0 ]
+    then
+      printf >&2 '  into "%s".\n' "$OPT_TAGSFILE"
+    fi
+    mv -f $TMP:M "$OPT_TAGSFILE"
+  fi
+}
+
+# Generate tags for the current directory.
+td_here() {
+  td_prep
+  [ -s $TMP:T ] || return 1
+  td_tag
+}
+
+# Generate tags for the current directory, and report an error if there are
+# no .td files present.
+do_here()
+{
+  if ! td_here
+  then
+    printf >&2 '%s: Nothing to do here.\n' "$SELF"
+    exit 1
+  fi
+}
+
+# Generate tags for all .td files under the current directory.
+do_recurse()
+{
+  td_find "$PWD"
+  td_dirs
+}
+
+# Generate tags for all .td files in LLVM.
+do_all()
+{
+  td_find "$LLVM_SRC_ROOT"
+  td_dirs
+}
+
+# Generate tags for each directory in the worklist $TMP:W.
+td_dirs()
+{
+  while read d
+  do
+    (cd "$d" && td_here)
+  done <$TMP:W
+}
+
+# Find directories containing .td files within the specified directory,
+# and record them in the worklist $TMP:W.
+td_find()
+{
+  find -L "$1" -type f -name '*.td' |
+    sed -e 's:/[^/]*$::' |
+    sort -u >$TMP:W
+  td_dump $TMP:W
+}
+
+# Generate tags for the specified code generator targets, or
+# if there are no arguments, all targets.
+do_targets() {
+  cd $LLVM_SRC_ROOT/lib/Target
+  if [ -z "$*" ]
+  then
+    td_find "$PWD"
+  else
+    # Check that every specified argument is a target directory;
+    # if not, list all target directories.
+    for d
+    do
+      if [ -d "$d" ] && dir_has_td "$d"
+      then
+        printf '%s/%s\n' "$PWD" "$d"
+      else
+        printf >&2 '%s: "%s" is not a target. Targets are:\n' "$SELF" "$d"
+        for d in *
+        do
+          [ -d "$d" ] || continue
+          dir_has_td "$d" && printf >&2 '  %s\n' "$d"
+        done
+        exit 2
+      fi
+    done >$TMP:W
+  fi
+  td_dirs
+}
+
+# Change to the directory at the top of the enclosing LLVM source tree,
+# if possible.
+llvm_src_root() {
+  while [ "$PWD" != / ]
+  do
+    # Use this directory if multiple notable subdirectories are present.
+    [ -d include/llvm -a -d lib/Target ] && return 0
+    cd ..
+  done
+  return 1
+}
+
+# Ensure sort(1) behaves consistently.
+LC_ALL=C
+export LC_ALL
+
+# Globals.
+TBLGEN=llvm-tblgen
+LLVM_SRC_ROOT=
+
+# Command options.
+OPT_TAGSFILE=tags
+OPT_RECIPES=0
+OPT_APPEND=0
+OPT_VERBOSE=0
+OPT_NOTBLGENERR=0
+
+while getopts 'af:hxqvHI:' opt
+do
+  case $opt in
+  a)
+    OPT_APPEND=1
+    ;;
+  f)
+    OPT_TAGSFILE="$OPTARG"
+    ;;
+  x)
+    OPT_RECIPES=1
+    ;;
+  q)
+    OPT_NOTBLGENERR=1
+    ;;
+  v)
+    OPT_VERBOSE=$((OPT_VERBOSE + 1))
+    ;;
+  I)
+    printf '%s\n' "$OPTARG" >>$TMP:D
+    ;;
+  [hH])
+    help
+    exit 0
+    ;;
+  *)
+    usage >&2
+    exit 4
+    ;;
+  esac
+done
+shift $((OPTIND - 1))
+
+# Handle the case where tdtags is a simple ctags(1)-like wrapper for tblgen.
+if [ $OPT_RECIPES -eq 0 ]
+then
+  if [ -z "$*" ]
+  then
+    help >&2
+    exit 5
+  fi
+  for i
+  do
+    printf '%s\n' "$i"
+  done >$TMP:T
+  td_tag
+  exit $?
+fi
+
+# Find the directory at the top of the enclosing LLVM source tree.
+if ! LLVM_SRC_ROOT=$(llvm_src_root && pwd)
+then
+  printf >&2 '%s: Run from within the LLVM source tree.\n' "$SELF"
+  exit 3
+fi
+
+# Select canned actions.
+RECIPE="$1"
+case "$RECIPE" in
+all)
+  shift
+  do_all
+  ;;
+.|cwd|here)
+  shift
+  do_here
+  ;;
+recurse)
+  shift
+  do_recurse
+  ;;
+target)
+  shift
+  do_targets "$@"
+  ;;
+*)
+  if [ -n "$RECIPE" ]
+  then
+    shift
+    printf >&2 '%s: Unknown recipe "-x %s". ' "$SELF" "$RECIPE"
+  fi
+  printf >&2 'Recipes:\n'
+  usage_recipes >&2
+  printf >&2 'Run "%s -H" for help.\n' "$SELF"
+  exit 6
+  ;;
+esac
+
+exit $?