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Diffstat (limited to 'src/output.c')
| -rw-r--r-- | src/output.c | 1017 |
1 files changed, 1017 insertions, 0 deletions
diff --git a/src/output.c b/src/output.c new file mode 100644 index 0000000..c378afe --- /dev/null +++ b/src/output.c @@ -0,0 +1,1017 @@ +/* GNU m4 -- A simple macro processor + + Copyright (C) 1989-1994, 2004-2013 Free Software Foundation, Inc. + + This file is part of GNU M4. + + GNU M4 is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + GNU M4 is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "m4.h" + +#include <limits.h> +#include <sys/stat.h> + +#include "gl_avltree_oset.h" +#include "gl_xoset.h" + +/* Size of initial in-memory buffer size for diversions. Small diversions + would usually fit in. */ +#define INITIAL_BUFFER_SIZE 512 + +/* Maximum value for the total of all in-memory buffer sizes for + diversions. */ +#define MAXIMUM_TOTAL_SIZE (512 * 1024) + +/* Size of buffer size to use while copying files. */ +#define COPY_BUFFER_SIZE (32 * 512) + +/* Output functions. Most of the complexity is for handling cpp like + sync lines. + + This code is fairly entangled with the code in input.c, and maybe it + belongs there? */ + +typedef struct temp_dir m4_temp_dir; + +/* When part of diversion_table, each struct m4_diversion either + represents an open file (zero size, non-NULL u.file), an in-memory + buffer (non-zero size, non-NULL u.buffer), or an unused placeholder + diversion (zero size, u is NULL, non-zero used indicates that a + file has been created). When not part of diversion_table, u.next + is a pointer to the free_list chain. */ + +typedef struct m4_diversion m4_diversion; + +struct m4_diversion + { + union + { + FILE *file; /* Diversion file on disk. */ + char *buffer; /* Malloc'd diversion buffer. */ + m4_diversion *next; /* Free-list pointer */ + } u; + int divnum; /* Which diversion this represents. */ + int size; /* Usable size before reallocation. */ + int used; /* Used buffer length, or tmp file exists. */ + }; + +/* Table of diversions 1 through INT_MAX. */ +static gl_oset_t diversion_table; + +/* Diversion 0 (not part of diversion_table). */ +static m4_diversion div0; + +/* Linked list of reclaimed diversion storage. */ +static m4_diversion *free_list; + +/* Obstack from which diversion storage is allocated. */ +static struct obstack diversion_storage; + +/* Total size of all in-memory buffer sizes. */ +static int total_buffer_size; + +/* The number of the currently active diversion. This variable is + maintained for the `divnum' builtin function. */ +int current_diversion; + +/* Current output diversion, NULL if output is being currently + discarded. output_diversion->u is guaranteed non-NULL except when + the diversion has never been used; use size to determine if it is a + malloc'd buffer or a FILE. output_diversion->used is 0 if u.file + is stdout, and non-zero if this is a malloc'd buffer or a temporary + diversion file. */ +static m4_diversion *output_diversion; + +/* Cache of output_diversion->u.file, only valid when + output_diversion->size is 0. */ +static FILE *output_file; + +/* Cache of output_diversion->u.buffer + output_diversion->used, only + valid when output_diversion->size is non-zero. */ +static char *output_cursor; + +/* Cache of output_diversion->size - output_diversion->used, only + valid when output_diversion->size is non-zero. */ +static int output_unused; + +/* Number of input line we are generating output for. */ +int output_current_line; + +/* Temporary directory holding all spilled diversion files. */ +static m4_temp_dir *output_temp_dir; + +/* Cache of most recently used spilled diversion files. */ +static FILE *tmp_file1; +static FILE *tmp_file2; + +/* Diversions that own tmp_file, or 0. */ +static int tmp_file1_owner; +static int tmp_file2_owner; + +/* True if tmp_file2 is more recently used. */ +static bool tmp_file2_recent; + + +/* Internal routines. */ + +/* Callback for comparing list elements ELT1 and ELT2 for order in + diversion_table. */ +static int +cmp_diversion_CB (const void *elt1, const void *elt2) +{ + const m4_diversion *d1 = (const m4_diversion *) elt1; + const m4_diversion *d2 = (const m4_diversion *) elt2; + /* No need to worry about overflow, since we don't create diversions + with negative divnum. */ + return d1->divnum - d2->divnum; +} + +/* Callback for comparing list element ELT against THRESHOLD. */ +static bool +threshold_diversion_CB (const void *elt, const void *threshold) +{ + const m4_diversion *diversion = (const m4_diversion *) elt; + /* No need to worry about overflow, since we don't create diversions + with negative divnum. */ + return diversion->divnum >= *(const int *) threshold; +} + +/* Clean up any temporary directory. Designed for use as an atexit + handler, where it is not safe to call exit() recursively; so this + calls _exit if a problem is encountered. */ +static void +cleanup_tmpfile (void) +{ + /* Close any open diversions. */ + bool fail = false; + + if (diversion_table) + { + const void *elt; + gl_oset_iterator_t iter = gl_oset_iterator (diversion_table); + while (gl_oset_iterator_next (&iter, &elt)) + { + m4_diversion *diversion = (m4_diversion *) elt; + if (!diversion->size && diversion->u.file + && close_stream_temp (diversion->u.file) != 0) + { + M4ERROR ((0, errno, + "cannot clean temporary file for diversion")); + fail = true; + } + } + gl_oset_iterator_free (&iter); + } + + /* Clean up the temporary directory. */ + if (cleanup_temp_dir (output_temp_dir) != 0) + fail = true; + if (fail) + _exit (exit_failure); +} + +/* Convert DIVNUM into a temporary file name for use in m4_tmp*. */ +static const char * +m4_tmpname (int divnum) +{ + static char *buffer; + static char *tail; + if (buffer == NULL) + { + tail = xasprintf ("%s/m4-%d", output_temp_dir->dir_name, INT_MAX); + buffer = (char *) obstack_copy0 (&diversion_storage, tail, + strlen (tail)); + free (tail); + tail = strrchr (buffer, '-') + 1; + } + assert (0 < divnum); + sprintf (tail, "%d", divnum); + return buffer; +} + +/* Create a temporary file for diversion DIVNUM open for reading and + writing in a secure temp directory. The file will be automatically + closed and deleted on a fatal signal. The file can be closed and + reopened with m4_tmpclose and m4_tmpopen, or moved with + m4_tmprename; when finally done with the file, close it with + m4_tmpremove. Exits on failure, so the return value is always an + open file. */ +static FILE * +m4_tmpfile (int divnum) +{ + const char *name; + FILE *file; + + if (output_temp_dir == NULL) + { + output_temp_dir = create_temp_dir ("m4-", NULL, true); + if (output_temp_dir == NULL) + M4ERROR ((EXIT_FAILURE, errno, + "cannot create temporary file for diversion")); + atexit (cleanup_tmpfile); + } + name = m4_tmpname (divnum); + register_temp_file (output_temp_dir, name); + file = fopen_temp (name, O_BINARY ? "wb+" : "w+"); + if (file == NULL) + { + unregister_temp_file (output_temp_dir, name); + M4ERROR ((EXIT_FAILURE, errno, + "cannot create temporary file for diversion")); + } + else if (set_cloexec_flag (fileno (file), true) != 0) + M4ERROR ((warning_status, errno, + "Warning: cannot protect diversion across forks")); + return file; +} + +/* Reopen a temporary file for diversion DIVNUM for reading and + writing in a secure temp directory. If REREAD, the file is + positioned at offset 0, otherwise the file is positioned at the + end. Exits on failure, so the return value is always an open + file. */ +static FILE * +m4_tmpopen (int divnum, bool reread) +{ + const char *name; + FILE *file; + + if (tmp_file1_owner == divnum) + { + if (reread && fseeko (tmp_file1, 0, SEEK_SET) != 0) + m4_error (EXIT_FAILURE, errno, + _("cannot seek within diversion")); + tmp_file2_recent = false; + return tmp_file1; + } + else if (tmp_file2_owner == divnum) + { + if (reread && fseeko (tmp_file2, 0, SEEK_SET) != 0) + m4_error (EXIT_FAILURE, errno, + _("cannot seek within diversion")); + tmp_file2_recent = true; + return tmp_file2; + } + name = m4_tmpname (divnum); + /* We need update mode, to avoid truncation. */ + file = fopen_temp (name, O_BINARY ? "rb+" : "r+"); + if (file == NULL) + M4ERROR ((EXIT_FAILURE, errno, + "cannot create temporary file for diversion")); + else if (set_cloexec_flag (fileno (file), true) != 0) + m4_error (0, errno, _("cannot protect diversion across forks")); + /* Update mode starts at the beginning of the stream, but sometimes + we want the end. */ + else if (!reread && fseeko (file, 0, SEEK_END) != 0) + m4_error (EXIT_FAILURE, errno, + _("cannot seek within diversion")); + return file; +} + +/* Close, but don't delete, a temporary FILE for diversion DIVNUM. To + reduce the I/O overhead of repeatedly opening and closing the same + file, this implementation caches the most recent spilled diversion. + On the other hand, keeping every spilled diversion open would run + into EMFILE limits. */ +static int +m4_tmpclose (FILE *file, int divnum) +{ + int result = 0; + if (divnum != tmp_file1_owner && divnum != tmp_file2_owner) + { + if (tmp_file2_recent) + { + if (tmp_file1_owner) + result = close_stream_temp (tmp_file1); + tmp_file1 = file; + tmp_file1_owner = divnum; + } + else + { + if (tmp_file2_owner) + result = close_stream_temp (tmp_file2); + tmp_file2 = file; + tmp_file2_owner = divnum; + } + } + return result; +} + +/* Delete a closed temporary FILE for diversion DIVNUM. */ +static int +m4_tmpremove (int divnum) +{ + if (divnum == tmp_file1_owner) + { + int result = close_stream_temp (tmp_file1); + if (result) + return result; + tmp_file1_owner = 0; + } + else if (divnum == tmp_file2_owner) + { + int result = close_stream_temp (tmp_file2); + if (result) + return result; + tmp_file2_owner = 0; + } + return cleanup_temp_file (output_temp_dir, m4_tmpname (divnum)); +} + +/* Transfer the temporary file for diversion OLDNUM to the previously + unused diversion NEWNUM. Return an open stream visiting the new + temporary file, positioned at the end, or exit on failure. */ +static FILE* +m4_tmprename (int oldnum, int newnum) +{ + /* m4_tmpname reuses its return buffer. */ + char *oldname = xstrdup (m4_tmpname (oldnum)); + const char *newname = m4_tmpname (newnum); + register_temp_file (output_temp_dir, newname); + if (oldnum == tmp_file1_owner) + { + /* Be careful of mingw, which can't rename an open file. */ + if (RENAME_OPEN_FILE_WORKS) + tmp_file1_owner = newnum; + else + { + if (close_stream_temp (tmp_file1)) + m4_error (EXIT_FAILURE, errno, + _("cannot close temporary file for diversion")); + tmp_file1_owner = 0; + } + } + else if (oldnum == tmp_file2_owner) + { + /* Be careful of mingw, which can't rename an open file. */ + if (RENAME_OPEN_FILE_WORKS) + tmp_file2_owner = newnum; + else + { + if (close_stream_temp (tmp_file2)) + m4_error (EXIT_FAILURE, errno, + _("cannot close temporary file for diversion")); + tmp_file2_owner = 0; + } + } + /* Either it is safe to rename an open file, or no one should have + oldname open at this point. */ + if (rename (oldname, newname)) + m4_error (EXIT_FAILURE, errno, + _("cannot create temporary file for diversion")); + unregister_temp_file (output_temp_dir, oldname); + free (oldname); + return m4_tmpopen (newnum, false); +} + + +/*------------------------. +| Output initialization. | +`------------------------*/ + +void +output_init (void) +{ + diversion_table = gl_oset_create_empty (GL_AVLTREE_OSET, cmp_diversion_CB, + NULL); + div0.u.file = stdout; + output_diversion = &div0; + output_file = stdout; + obstack_init (&diversion_storage); +} + +void +output_exit (void) +{ + /* Order is important, since we may have registered cleanup_tmpfile + as an atexit handler, and it must not traverse stale memory. */ + gl_oset_t table = diversion_table; + if (tmp_file1_owner) + m4_tmpremove (tmp_file1_owner); + if (tmp_file2_owner) + m4_tmpremove (tmp_file2_owner); + diversion_table = NULL; + gl_oset_free (table); + obstack_free (&diversion_storage, NULL); +} + +/*----------------------------------------------------------------. +| Reorganize in-memory diversion buffers so the current diversion | +| can accomodate LENGTH more characters without further | +| reorganization. The current diversion buffer is made bigger if | +| possible. But to make room for a bigger buffer, one of the | +| in-memory diversion buffers might have to be flushed to a newly | +| created temporary file. This flushed buffer might well be the | +| current one. | +`----------------------------------------------------------------*/ + +static void +make_room_for (int length) +{ + int wanted_size; + m4_diversion *selected_diversion = NULL; + + /* Compute needed size for in-memory buffer. Diversions in-memory + buffers start at 0 bytes, then 512, then keep doubling until it is + decided to flush them to disk. */ + + output_diversion->used = output_diversion->size - output_unused; + + for (wanted_size = output_diversion->size; + wanted_size < output_diversion->used + length; + wanted_size = wanted_size == 0 ? INITIAL_BUFFER_SIZE : wanted_size * 2) + ; + + /* Check if we are exceeding the maximum amount of buffer memory. */ + + if (total_buffer_size - output_diversion->size + wanted_size + > MAXIMUM_TOTAL_SIZE) + { + int selected_used; + char *selected_buffer; + m4_diversion *diversion; + int count; + gl_oset_iterator_t iter; + const void *elt; + + /* Find out the buffer having most data, in view of flushing it to + disk. Fake the current buffer as having already received the + projected data, while making the selection. So, if it is + selected indeed, we will flush it smaller, before it grows. */ + + selected_diversion = output_diversion; + selected_used = output_diversion->used + length; + + iter = gl_oset_iterator (diversion_table); + while (gl_oset_iterator_next (&iter, &elt)) + { + diversion = (m4_diversion *) elt; + if (diversion->used > selected_used) + { + selected_diversion = diversion; + selected_used = diversion->used; + } + } + gl_oset_iterator_free (&iter); + + /* Create a temporary file, write the in-memory buffer of the + diversion to this file, then release the buffer. Zero the + diversion before doing anything that can exit () (including + m4_tmpfile), so that the atexit handler doesn't try to close + a garbage pointer as a file. */ + + selected_buffer = selected_diversion->u.buffer; + total_buffer_size -= selected_diversion->size; + selected_diversion->size = 0; + selected_diversion->u.file = NULL; + selected_diversion->u.file = m4_tmpfile (selected_diversion->divnum); + + if (selected_diversion->used > 0) + { + count = fwrite (selected_buffer, (size_t) selected_diversion->used, + 1, selected_diversion->u.file); + if (count != 1) + M4ERROR ((EXIT_FAILURE, errno, + "ERROR: cannot flush diversion to temporary file")); + } + + /* Reclaim the buffer space for other diversions. */ + + free (selected_buffer); + selected_diversion->used = 1; + } + + /* Reload output_file, just in case the flushed diversion was current. */ + + if (output_diversion == selected_diversion) + { + /* The flushed diversion was current indeed. */ + + output_file = output_diversion->u.file; + output_cursor = NULL; + output_unused = 0; + } + else + { + /* Close any selected file since it is not the current diversion. */ + if (selected_diversion) + { + FILE *file = selected_diversion->u.file; + selected_diversion->u.file = NULL; + if (m4_tmpclose (file, selected_diversion->divnum) != 0) + m4_error (0, errno, + _("cannot close temporary file for diversion")); + } + + /* The current buffer may be safely reallocated. */ + { + char *buffer = output_diversion->u.buffer; + output_diversion->u.buffer = xcharalloc ((size_t) wanted_size); + memcpy (output_diversion->u.buffer, buffer, output_diversion->used); + free (buffer); + } + + total_buffer_size += wanted_size - output_diversion->size; + output_diversion->size = wanted_size; + + output_cursor = output_diversion->u.buffer + output_diversion->used; + output_unused = wanted_size - output_diversion->used; + } +} + +/*--------------------------------------------------------------. +| Output one character CHAR, when it is known that it goes to a | +| diversion file or an in-memory diversion buffer. | +`--------------------------------------------------------------*/ + +#define OUTPUT_CHARACTER(Char) \ + if (output_file) \ + putc ((Char), output_file); \ + else if (output_unused == 0) \ + output_character_helper ((Char)); \ + else \ + (output_unused--, *output_cursor++ = (Char)) + +static void +output_character_helper (int character) +{ + make_room_for (1); + + if (output_file) + putc (character, output_file); + else + { + *output_cursor++ = character; + output_unused--; + } +} + +/*-------------------------------------------------------------------. +| Output one TEXT having LENGTH characters, when it is known that it | +| goes to a diversion file or an in-memory diversion buffer. | +`-------------------------------------------------------------------*/ + +void +output_text (const char *text, int length) +{ + int count; + + if (!output_diversion || !length) + return; + + if (!output_file && length > output_unused) + make_room_for (length); + + if (output_file) + { + count = fwrite (text, length, 1, output_file); + if (count != 1) + M4ERROR ((EXIT_FAILURE, errno, "ERROR: copying inserted file")); + } + else + { + memcpy (output_cursor, text, (size_t) length); + output_cursor += length; + output_unused -= length; + } +} + +/*--------------------------------------------------------------------. +| Add some text into an obstack OBS, taken from TEXT, having LENGTH | +| characters. If OBS is NULL, output the text to an external file | +| or an in-memory diversion buffer instead. If OBS is NULL, and | +| there is no output file, the text is discarded. LINE is the line | +| where the token starts (not necessarily current_line, in the case | +| of multiline tokens). | +| | +| If we are generating sync lines, the output has to be examined, | +| because we need to know how much output each input line generates. | +| In general, sync lines are output whenever a single input lines | +| generates several output lines, or when several input lines do not | +| generate any output. | +`--------------------------------------------------------------------*/ + +void +shipout_text (struct obstack *obs, const char *text, int length, int line) +{ + static bool start_of_output_line = true; + const char *cursor; + + /* If output goes to an obstack, merely add TEXT to it. */ + + if (obs != NULL) + { + obstack_grow (obs, text, length); + return; + } + + /* Do nothing if TEXT should be discarded. */ + + if (output_diversion == NULL) + return; + + /* Output TEXT to a file, or in-memory diversion buffer. */ + + if (!sync_output) + switch (length) + { + + /* In-line short texts. */ + + case 8: OUTPUT_CHARACTER (*text); text++; + case 7: OUTPUT_CHARACTER (*text); text++; + case 6: OUTPUT_CHARACTER (*text); text++; + case 5: OUTPUT_CHARACTER (*text); text++; + case 4: OUTPUT_CHARACTER (*text); text++; + case 3: OUTPUT_CHARACTER (*text); text++; + case 2: OUTPUT_CHARACTER (*text); text++; + case 1: OUTPUT_CHARACTER (*text); + case 0: + return; + + /* Optimize longer texts. */ + + default: + output_text (text, length); + } + else + { + /* Check for syncline only at the start of a token. Multiline + tokens, and tokens that are out of sync but in the middle of + the line, must wait until the next raw newline triggers a + syncline. */ + if (start_of_output_line) + { + start_of_output_line = false; + output_current_line++; +#ifdef DEBUG_OUTPUT + xfprintf (stderr, "DEBUG: line %d, cur %d, cur out %d\n", + line, current_line, output_current_line); +#endif + + /* Output a `#line NUM' synchronization directive if needed. + If output_current_line was previously given a negative + value (invalidated), output `#line NUM "FILE"' instead. */ + + if (output_current_line != line) + { + OUTPUT_CHARACTER ('#'); + OUTPUT_CHARACTER ('l'); + OUTPUT_CHARACTER ('i'); + OUTPUT_CHARACTER ('n'); + OUTPUT_CHARACTER ('e'); + OUTPUT_CHARACTER (' '); + for (cursor = ntoa (line, 10); *cursor; cursor++) + OUTPUT_CHARACTER (*cursor); + if (output_current_line < 1 && current_file[0] != '\0') + { + OUTPUT_CHARACTER (' '); + OUTPUT_CHARACTER ('"'); + for (cursor = current_file; *cursor; cursor++) + OUTPUT_CHARACTER (*cursor); + OUTPUT_CHARACTER ('"'); + } + OUTPUT_CHARACTER ('\n'); + output_current_line = line; + } + } + + /* Output the token, and track embedded newlines. */ + for (; length-- > 0; text++) + { + if (start_of_output_line) + { + start_of_output_line = false; + output_current_line++; +#ifdef DEBUG_OUTPUT + xfprintf (stderr, "DEBUG: line %d, cur %d, cur out %d\n", + line, current_line, output_current_line); +#endif + } + OUTPUT_CHARACTER (*text); + if (*text == '\n') + start_of_output_line = true; + } + } +} + +/* Functions for use by diversions. */ + +/*------------------------------------------------------------------. +| Make a file for diversion DIVNUM, and install it in the diversion | +| table. Grow the size of the diversion table as needed. | +`------------------------------------------------------------------*/ + +/* The number of possible diversions is limited only by memory and + available file descriptors (each overflowing diversion uses one). */ + +void +make_diversion (int divnum) +{ + m4_diversion *diversion = NULL; + + if (current_diversion == divnum) + return; + + if (output_diversion) + { + if (!output_diversion->size && !output_diversion->u.file) + { + assert (!output_diversion->used); + if (!gl_oset_remove (diversion_table, output_diversion)) + assert (false); + output_diversion->u.next = free_list; + free_list = output_diversion; + } + else if (output_diversion->size) + output_diversion->used = output_diversion->size - output_unused; + else if (output_diversion->used) + { + FILE *file = output_diversion->u.file; + output_diversion->u.file = NULL; + if (m4_tmpclose (file, output_diversion->divnum) != 0) + m4_error (0, errno, + _("cannot close temporary file for diversion")); + } + output_diversion = NULL; + output_file = NULL; + output_cursor = NULL; + output_unused = 0; + } + + current_diversion = divnum; + + if (divnum < 0) + return; + + if (divnum == 0) + diversion = &div0; + else + { + const void *elt; + if (gl_oset_search_atleast (diversion_table, threshold_diversion_CB, + &divnum, &elt)) + { + m4_diversion *temp = (m4_diversion *) elt; + if (temp->divnum == divnum) + diversion = temp; + } + } + if (diversion == NULL) + { + /* First time visiting this diversion. */ + if (free_list) + { + diversion = free_list; + free_list = diversion->u.next; + } + else + { + diversion = (m4_diversion *) obstack_alloc (&diversion_storage, + sizeof *diversion); + diversion->size = 0; + diversion->used = 0; + } + diversion->u.file = NULL; + diversion->divnum = divnum; + gl_oset_add (diversion_table, diversion); + } + + output_diversion = diversion; + if (output_diversion->size) + { + output_cursor = output_diversion->u.buffer + output_diversion->used; + output_unused = output_diversion->size - output_diversion->used; + } + else + { + if (!output_diversion->u.file && output_diversion->used) + output_diversion->u.file = m4_tmpopen (output_diversion->divnum, + false); + output_file = output_diversion->u.file; + } + output_current_line = -1; +} + +/*-------------------------------------------------------------------. +| Insert a FILE into the current output file, in the same manner | +| diversions are handled. This allows files to be included, without | +| having them rescanned by m4. | +`-------------------------------------------------------------------*/ + +void +insert_file (FILE *file) +{ + static char buffer[COPY_BUFFER_SIZE]; + size_t length; + + /* Optimize out inserting into a sink. */ + if (!output_diversion) + return; + + /* Insert output by big chunks. */ + while (1) + { + length = fread (buffer, 1, sizeof buffer, file); + if (ferror (file)) + M4ERROR ((EXIT_FAILURE, errno, "error reading inserted file")); + if (length == 0) + break; + output_text (buffer, length); + } +} + +/*-------------------------------------------------------------------. +| Insert DIVERSION (but not div0) into the current output file. The | +| diversion is NOT placed on the expansion obstack, because it must | +| not be rescanned. When the file is closed, it is deleted by the | +| system. | +`-------------------------------------------------------------------*/ + +static void +insert_diversion_helper (m4_diversion *diversion) +{ + /* Effectively undivert only if an output stream is active. */ + if (output_diversion) + { + if (diversion->size) + { + if (!output_diversion->u.file) + { + /* Transferring diversion metadata is faster than + copying contents. */ + assert (!output_diversion->used && output_diversion != &div0 + && !output_file); + output_diversion->u.buffer = diversion->u.buffer; + output_diversion->size = diversion->size; + output_cursor = diversion->u.buffer + diversion->used; + output_unused = diversion->size - diversion->used; + diversion->u.buffer = NULL; + } + else + { + /* Avoid double-charging the total in-memory size when + transferring from one in-memory diversion to + another. */ + total_buffer_size -= diversion->size; + output_text (diversion->u.buffer, diversion->used); + } + } + else if (!output_diversion->u.file) + { + /* Transferring diversion metadata is faster than copying + contents. */ + assert (!output_diversion->used && output_diversion != &div0 + && !output_file); + output_diversion->u.file = m4_tmprename (diversion->divnum, + output_diversion->divnum); + output_diversion->used = 1; + output_file = output_diversion->u.file; + diversion->u.file = NULL; + diversion->size = 1; + } + else + { + if (!diversion->u.file) + diversion->u.file = m4_tmpopen (diversion->divnum, true); + insert_file (diversion->u.file); + } + + output_current_line = -1; + } + + /* Return all space used by the diversion. */ + if (diversion->size) + { + if (!output_diversion) + total_buffer_size -= diversion->size; + free (diversion->u.buffer); + diversion->size = 0; + } + else + { + if (diversion->u.file) + { + FILE *file = diversion->u.file; + diversion->u.file = NULL; + if (m4_tmpclose (file, diversion->divnum) != 0) + m4_error (0, errno, + _("cannot clean temporary file for diversion")); + } + if (m4_tmpremove (diversion->divnum) != 0) + M4ERROR ((0, errno, "cannot clean temporary file for diversion")); + } + diversion->used = 0; + gl_oset_remove (diversion_table, diversion); + diversion->u.next = free_list; + free_list = diversion; +} + +/*------------------------------------------------------------------. +| Insert diversion number DIVNUM into the current output file. The | +| diversion is NOT placed on the expansion obstack, because it must | +| not be rescanned. When the file is closed, it is deleted by the | +| system. | +`------------------------------------------------------------------*/ + +void +insert_diversion (int divnum) +{ + const void *elt; + + /* Do not care about nonexistent diversions, and undiverting stdout + or self is a no-op. */ + if (divnum <= 0 || current_diversion == divnum) + return; + if (gl_oset_search_atleast (diversion_table, threshold_diversion_CB, + &divnum, &elt)) + { + m4_diversion *diversion = (m4_diversion *) elt; + if (diversion->divnum == divnum) + insert_diversion_helper (diversion); + } +} + +/*----------------------------------------------------------------. +| Get back all diversions. This is done just before exiting from | +| main, and from m4_undivert (), if called without arguments. | +`----------------------------------------------------------------*/ + +void +undivert_all (void) +{ + const void *elt; + gl_oset_iterator_t iter = gl_oset_iterator (diversion_table); + while (gl_oset_iterator_next (&iter, &elt)) + { + m4_diversion *diversion = (m4_diversion *) elt; + if (diversion->divnum != current_diversion) + insert_diversion_helper (diversion); + } + gl_oset_iterator_free (&iter); +} + +/*-------------------------------------------------------------. +| Produce all diversion information in frozen format on FILE. | +`-------------------------------------------------------------*/ + +void +freeze_diversions (FILE *file) +{ + int saved_number; + int last_inserted; + gl_oset_iterator_t iter; + const void *elt; + + saved_number = current_diversion; + last_inserted = 0; + make_diversion (0); + output_file = file; /* kludge in the frozen file */ + + iter = gl_oset_iterator (diversion_table); + while (gl_oset_iterator_next (&iter, &elt)) + { + m4_diversion *diversion = (m4_diversion *) elt; + if (diversion->size || diversion->used) + { + if (diversion->size) + xfprintf (file, "D%d,%d\n", diversion->divnum, diversion->used); + else + { + struct stat file_stat; + diversion->u.file = m4_tmpopen (diversion->divnum, true); + if (fstat (fileno (diversion->u.file), &file_stat) < 0) + M4ERROR ((EXIT_FAILURE, errno, "cannot stat diversion")); + if (file_stat.st_size < 0 + || (file_stat.st_size + 0UL + != (unsigned long int) file_stat.st_size)) + M4ERROR ((EXIT_FAILURE, 0, "diversion too large")); + xfprintf (file, "D%d,%lu\n", diversion->divnum, + (unsigned long int) file_stat.st_size); + } + + insert_diversion_helper (diversion); + putc ('\n', file); + + last_inserted = diversion->divnum; + } + } + gl_oset_iterator_free (&iter); + + /* Save the active diversion number, if not already. */ + + if (saved_number != last_inserted) + xfprintf (file, "D%d,0\n\n", saved_number); +} |