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author | Dirk Herrmann <dirk@dirk-herrmanns-seiten.de> | 2003-04-21 13:33:48 +0000 |
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committer | Dirk Herrmann <dirk@dirk-herrmanns-seiten.de> | 2003-04-21 13:33:48 +0000 |
commit | fce0b22d94aa0a12dbf5823d129c8e860cd7e210 (patch) | |
tree | f58b8b28e636b1bf9991c76b286b40054b06dd83 /libguile | |
parent | 1685446c0d77ed3386f77b306b6b47c451394daa (diff) | |
download | guile-fce0b22d94aa0a12dbf5823d129c8e860cd7e210.tar.gz |
* __scm.h: Fixed comment about the SCM_DEBUG_TYPING_STRICTNESS
debug option.
Diffstat (limited to 'libguile')
-rw-r--r-- | libguile/ChangeLog | 5 | ||||
-rw-r--r-- | libguile/__scm.h | 29 |
2 files changed, 28 insertions, 6 deletions
diff --git a/libguile/ChangeLog b/libguile/ChangeLog index 4e02b5c87..71a49a468 100644 --- a/libguile/ChangeLog +++ b/libguile/ChangeLog @@ -1,5 +1,10 @@ 2003-04-21 Dirk Herrmann <D.Herrmann@tu-bs.de> + * __scm.h: Fixed comment about the SCM_DEBUG_TYPING_STRICTNESS + debug option. + +2003-04-21 Dirk Herrmann <D.Herrmann@tu-bs.de> + * list.c (scm_ilength, scm_last_pair), unif.c (l2ra):Prefer !SCM_CONSP over SCM_NCONSP. Now, guile itself does not include any calls to SCM_NCONSP any more. diff --git a/libguile/__scm.h b/libguile/__scm.h index e8d1dd26c..c20a9c240 100644 --- a/libguile/__scm.h +++ b/libguile/__scm.h @@ -175,9 +175,10 @@ * These compile time options determine whether to include code that is only * useful for debugging guile itself or C level extensions to guile. The * common prefix for all option macros of this kind is "SCM_DEBUG_". It is - * guaranteed that a macro named SCM_DEBUG_XXX is defined to be either 0 or 1, - * i. e. there is no need to test for the undefined case. This allows to use - * these definitions comfortably within code, as in the following example: + * guaranteed that a macro named SCM_DEBUG_XXX is always defined (typically to + * either 0 or 1), i. e. there is no need to test for the undefined case. + * This allows to use these definitions comfortably within code, as in the + * following example: * #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0) * Any sane compiler will remove the unused branch without any performance * penalty for the resulting code. @@ -230,9 +231,25 @@ #define SCM_DEBUG_REST_ARGUMENT SCM_DEBUG #endif -/* Use this for _compile time_ type checking only, since the compiled result - * will be quite inefficient. The right way to make use of this option is to - * do a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=1', fix your +/* The macro SCM_DEBUG_TYPING_STRICTNESS indicates what level of type checking + * shall be performed with respect to the use of the SCM datatype. The macro + * may be defined to one of the values 0, 1 and 2. + * + * A value of 0 means that there will be no compile time type checking, since + * the SCM datatype will be declared as an integral type. This setting should + * only be used on systems, where casting from integral types to pointers may + * lead to loss of bit information. + * + * A value of 1 means that there will an intermediate level of compile time + * type checking, since the SCM datatype will be declared as a pointer to an + * undefined struct. This setting is the default, since it does not cost + * anything in terms of performance or code size. + * + * A value of 2 provides a maximum level of compile time type checking since + * the SCM datatype will be declared as a struct. This setting should be used + * for _compile time_ type checking only, since the compiled result is likely + * to be quite inefficient. The right way to make use of this option is to do + * a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=2', fix your * errors, and then do 'make clean; make'. */ #ifndef SCM_DEBUG_TYPING_STRICTNESS |