cosmopolitan/third_party/ctags/make.c

/*
 *   $Id: make.c 751 2010-02-27 17:41:57Z elliotth $
 *
 *   Copyright (c) 2000-2005, Darren Hiebert
 *
 *   This source code is released for free distribution under the terms of the
 *   GNU General Public License.
 *
 *   This module contains functions for generating tags for makefiles.
 */
#include "third_party/ctags/general.h"
/* must always come first */
#include "third_party/ctags/options.h"
#include "third_party/ctags/parse.h"
#include "third_party/ctags/read.h"
#include "third_party/ctags/vstring.h"

/*
 *   DATA DEFINITIONS
 */
typedef enum { K_MACRO } shKind;

static kindOption MakeKinds[] = {{TRUE, 'm', "macro", "macros"}};

/*
 *   FUNCTION DEFINITIONS
 */

static int nextChar(void) {
  int c = fileGetc();
  if (c == '\\') {
    c = fileGetc();
    if (c == '\n') c = fileGetc();
  }
  return c;
}

static void skipLine(void) {
  int c;
  do
    c = nextChar();
  while (c != EOF && c != '\n');
  if (c == '\n') fileUngetc(c);
}

static int skipToNonWhite(void) {
  int c;
  do
    c = nextChar();
  while (c != '\n' && isspace(c));
  return c;
}

static boolean isIdentifier(int c) {
  return (boolean)(c != '\0' && (isalnum(c) || strchr(".-_", c) != NULL));
}

static void readIdentifier(const int first, vString *const id) {
  int c = first;
  vStringClear(id);
  while (isIdentifier(c)) {
    vStringPut(id, c);
    c = nextChar();
  }
  fileUngetc(c);
  vStringTerminate(id);
}

static void skipToMatch(const char *const pair) {
  const int begin = pair[0], end = pair[1];
  const unsigned long inputLineNumber = getInputLineNumber();
  int matchLevel = 1;
  int c = '\0';

  while (matchLevel > 0) {
    c = nextChar();
    if (c == begin)
      ++matchLevel;
    else if (c == end)
      --matchLevel;
    else if (c == '\n' || c == EOF)
      break;
  }
  if (c == EOF)
    verbose("%s: failed to find match for '%c' at line %lu\n",
            getInputFileName(), begin, inputLineNumber);
}

static void findMakeTags(void) {
  vString *name = vStringNew();
  boolean newline = TRUE;
  boolean in_define = FALSE;
  boolean in_rule = FALSE;
  boolean variable_possible = TRUE;
  int c;

  while ((c = nextChar()) != EOF) {
    if (newline) {
      if (in_rule) {
        if (c == '\t') {
          skipLine(); /* skip rule */
          continue;
        } else
          in_rule = FALSE;
      }
      variable_possible = (boolean)(!in_rule);
      newline = FALSE;
    }
    if (c == '\n')
      newline = TRUE;
    else if (isspace(c))
      continue;
    else if (c == '#')
      skipLine();
    else if (c == '(')
      skipToMatch("()");
    else if (c == '{')
      skipToMatch("{}");
    else if (c == ':') {
      variable_possible = TRUE;
      in_rule = TRUE;
    } else if (variable_possible && isIdentifier(c)) {
      readIdentifier(c, name);
      if (strcmp(vStringValue(name), "endef") == 0)
        in_define = FALSE;
      else if (in_define)
        skipLine();
      else if (strcmp(vStringValue(name), "define") == 0 && isIdentifier(c)) {
        in_define = TRUE;
        c = skipToNonWhite();
        readIdentifier(c, name);
        makeSimpleTag(name, MakeKinds, K_MACRO);
        skipLine();
      } else {
        if (strcmp(vStringValue(name), "export") == 0 && isIdentifier(c)) {
          c = skipToNonWhite();
          readIdentifier(c, name);
        }
        c = skipToNonWhite();
        if (strchr(":?+", c) != NULL) {
          boolean append = (boolean)(c == '+');
          if (c == ':') in_rule = TRUE;
          c = nextChar();
          if (c != '=')
            fileUngetc(c);
          else if (append) {
            skipLine();
            continue;
          }
        }
        if (c == '=') {
          makeSimpleTag(name, MakeKinds, K_MACRO);
          in_rule = FALSE;
          skipLine();
        }
      }
    } else
      variable_possible = FALSE;
  }
  vStringDelete(name);
}

extern parserDefinition *MakefileParser(void) {
  static const char *const patterns[] = {"[Mm]akefile", "GNUmakefile", NULL};
  static const char *const extensions[] = {"mak", "mk", NULL};
  parserDefinition *const def = parserNew("Make");
  def->kinds = MakeKinds;
  def->kindCount = KIND_COUNT(MakeKinds);
  def->patterns = patterns;
  def->extensions = extensions;
  def->parser = findMakeTags;
  return def;
}

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