diff options
| -rw-r--r-- | src/ChangeLog | 21 | ||||
| -rw-r--r-- | src/buffer.h | 43 | ||||
| -rw-r--r-- | src/casetab.c | 6 | ||||
| -rw-r--r-- | src/character.h | 3 | ||||
| -rw-r--r-- | src/lisp.h | 47 |
5 files changed, 67 insertions, 53 deletions
diff --git a/src/ChangeLog b/src/ChangeLog index 7468af4c725..7e873e3d85d 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,5 +1,26 @@ 2011-03-15 Paul Eggert <eggert@cs.ucla.edu> + Fix a race condition diagnosed by gcc -Wsequence-point (Bug#8254). + An expression of the form (DOWNCASE (x) == DOWNCASE (y)), found in + dired.c's scmp function, had undefined behavior. + * lisp.h (DOWNCASE_TABLE, UPCASE_TABLE, DOWNCASE, UPPERCASEP): + (NOCASEP, LOWERCASEP, UPCASE, UPCASE1): Move from here ... + * buffer.h: ... to here, because these macros use current_buffer, + and the new implementation with inline functions needs to have + current_buffer in scope now, rather than later when the macros + are used. + (downcase, upcase1): New static inline functions. + (DOWNCASE, UPCASE1): Reimplement using these functions. + This avoids undefined behavior in expressions like + DOWNCASE (x) == DOWNCASE (y), which previously suffered + from race conditions in accessing the global variables + case_temp1 and case_temp2. + * casetab.c (case_temp1, case_temp2): Remove; no longer needed. + * lisp.h (case_temp1, case_temp2): Remove their decls. + * character.h (ASCII_CHAR_P): Move from here ... + * lisp.h: ... to here, so that the inline functions mentioned + above can use them. + * dired.c (directory_files_internal_unwind): Now static. * fileio.c (file_name_as_directory, directory_file_name): diff --git a/src/buffer.h b/src/buffer.h index 0975d2e3adc..996e4e59c27 100644 --- a/src/buffer.h +++ b/src/buffer.h @@ -1026,4 +1026,47 @@ extern int last_per_buffer_idx; #define PER_BUFFER_VALUE(BUFFER, OFFSET) \ (*(Lisp_Object *)((OFFSET) + (char *) (BUFFER))) + +/* Current buffer's map from characters to lower-case characters. */ + +#define DOWNCASE_TABLE BVAR (current_buffer, downcase_table) + +/* Current buffer's map from characters to upper-case characters. */ + +#define UPCASE_TABLE BVAR (current_buffer, upcase_table) + +/* Downcase a character, or make no change if that cannot be done. */ + +static inline EMACS_INT +downcase (int ch) +{ + Lisp_Object down = CHAR_TABLE_REF (DOWNCASE_TABLE, ch); + return NATNUMP (down) ? XFASTINT (down) : ch; +} +#define DOWNCASE(CH) downcase (CH) + +/* 1 if CH is upper case. */ + +#define UPPERCASEP(CH) (DOWNCASE (CH) != (CH)) +/* 1 if CH is neither upper nor lower case. */ + +#define NOCASEP(CH) (UPCASE1 (CH) == (CH)) + +/* 1 if CH is lower case. */ + +#define LOWERCASEP(CH) (!UPPERCASEP (CH) && !NOCASEP(CH)) + +/* Upcase a character, or make no change if that cannot be done. */ + +#define UPCASE(CH) (!UPPERCASEP (CH) ? UPCASE1 (CH) : (CH)) + +/* Upcase a character known to be not upper case. */ + +static inline EMACS_INT +upcase1 (int ch) +{ + Lisp_Object up = CHAR_TABLE_REF (UPCASE_TABLE, ch); + return NATNUMP (up) ? XFASTINT (up) : ch; +} +#define UPCASE1(CH) upcase1 (CH) diff --git a/src/casetab.c b/src/casetab.c index 5207e5315ae..56f6b065358 100644 --- a/src/casetab.c +++ b/src/casetab.c @@ -28,11 +28,6 @@ Lisp_Object Qcase_table_p, Qcase_table; Lisp_Object Vascii_downcase_table, Vascii_upcase_table; Lisp_Object Vascii_canon_table, Vascii_eqv_table; -/* Used as a temporary in DOWNCASE and other macros in lisp.h. No - need to mark it, since it is used only very temporarily. */ -int case_temp1; -Lisp_Object case_temp2; - static void set_canon (Lisp_Object case_table, Lisp_Object range, Lisp_Object elt); static void set_identity (Lisp_Object table, Lisp_Object c, Lisp_Object elt); static void shuffle (Lisp_Object table, Lisp_Object c, Lisp_Object elt); @@ -302,4 +297,3 @@ syms_of_casetab (void) defsubr (&Sset_case_table); defsubr (&Sset_standard_case_table); } - diff --git a/src/character.h b/src/character.h index d29ab41557b..6d5b8110109 100644 --- a/src/character.h +++ b/src/character.h @@ -128,9 +128,6 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ XSETCDR ((x), tmp); \ } while (0) -/* Nonzero iff C is an ASCII character. */ -#define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80) - /* Nonzero iff C is a character of code less than 0x100. */ #define SINGLE_BYTE_CHAR_P(c) ((unsigned) (c) < 0x100) diff --git a/src/lisp.h b/src/lisp.h index 3ba18186497..15c13e0467b 100644 --- a/src/lisp.h +++ b/src/lisp.h @@ -841,6 +841,9 @@ struct Lisp_Vector #endif /* not __GNUC__ */ +/* Nonzero iff C is an ASCII character. */ +#define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80) + /* Almost equivalent to Faref (CT, IDX) with optimization for ASCII characters. Do not check validity of CT. */ #define CHAR_TABLE_REF(CT, IDX) \ @@ -2041,50 +2044,6 @@ extern int pending_signals; #define QUITP (!NILP (Vquit_flag) && NILP (Vinhibit_quit)) -/* Variables used locally in the following case handling macros. */ -extern int case_temp1; -extern Lisp_Object case_temp2; - -/* Current buffer's map from characters to lower-case characters. */ - -#define DOWNCASE_TABLE BVAR (current_buffer, downcase_table) - -/* Current buffer's map from characters to upper-case characters. */ - -#define UPCASE_TABLE BVAR (current_buffer, upcase_table) - -/* Downcase a character, or make no change if that cannot be done. */ - -#define DOWNCASE(CH) \ - ((case_temp1 = (CH), \ - case_temp2 = CHAR_TABLE_REF (DOWNCASE_TABLE, case_temp1), \ - NATNUMP (case_temp2)) \ - ? XFASTINT (case_temp2) : case_temp1) - -/* 1 if CH is upper case. */ - -#define UPPERCASEP(CH) (DOWNCASE (CH) != (CH)) - -/* 1 if CH is neither upper nor lower case. */ - -#define NOCASEP(CH) (UPCASE1 (CH) == (CH)) - -/* 1 if CH is lower case. */ - -#define LOWERCASEP(CH) (!UPPERCASEP (CH) && !NOCASEP(CH)) - -/* Upcase a character, or make no change if that cannot be done. */ - -#define UPCASE(CH) (!UPPERCASEP (CH) ? UPCASE1 (CH) : (CH)) - -/* Upcase a character known to be not upper case. */ - -#define UPCASE1(CH) \ - ((case_temp1 = (CH), \ - case_temp2 = CHAR_TABLE_REF (UPCASE_TABLE, case_temp1), \ - NATNUMP (case_temp2)) \ - ? XFASTINT (case_temp2) : case_temp1) - extern Lisp_Object Vascii_downcase_table, Vascii_upcase_table; extern Lisp_Object Vascii_canon_table, Vascii_eqv_table; |