listing: add __?LIST_OPTIONS?__ and __?LIST_OPTIONS_DEFAULT?__ macros

Add macros to query the current state of the listing options, add
appropriate documentation.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

asm/preproc.c

@@ -8257,6 +8257,37 @@ err:
     return make_tok_num(NULL, val);
 }
 
+/*
+ * Given the currently default or command-line default listing options
+ */
+static Token *
+get_list_options(uint64_t optmask)
+{
+    static const char optchars[63] =
+        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+    char optbuf[65], *p;
+    unsigned int i;
+
+    p = optbuf;
+    for (i = 0; i < 62; i++) {
+        if (optmask & 4)
+            *p++ = optchars[i];
+        optmask >>= 1;
+    }
+    *p = '\0';
+
+    return make_tok_qstr_len(NULL, optbuf, p-optbuf);
+}
+
+static Token *
+stdmac_list_options(const SMacro *s, Token **params, int nparam)
+{
+    (void)s;
+    (void)params;
+    (void)nparam;
+    return get_list_options(active_list_options);
+}
+
 /*
  * Wrapper around define_smacro() which also checks to see if it is
  * a preprocessor directive, so that pp_op_may_be_function[] needs to
@@ -8295,6 +8326,7 @@ static void pp_add_magic_simple(void)
         { "__?BITS?__",  true, 0, 0, stdmac_bits },
         { "__?PTR?__",   true, 0, 0, stdmac_ptr },
         { "__?DEFAULT?__", true, 0, 0, stdmac_default },
+        { "__?LIST_OPTIONS?__", true, 0, 0, stdmac_list_options },
         { "%abs",        false, 1, SPARM_EVAL, stdmac_abs },
         { "%chr",        false, 1, SPARM_EVAL|SPARM_OPTIONAL|SPARM_VARADIC, stdmac_chr },
         { "%count",      false, 1, SPARM_VARADIC, stdmac_count },
@@ -8552,6 +8584,12 @@ static void pp_add_limits_stdmac(void)
     define_smacro("__?NASM_LIMITS?__", true, t, NULL);
 }
 
+static void pp_add_list_options_default_stdmac(void)
+{
+    define_smacro("__?LIST_OPTIONS_DEFAULT?__", true,
+                  get_list_options(cmdline_list_options), NULL);
+}
+
 static void pp_reset_stdmac(enum preproc_mode mode)
 {
     int apass;
@@ -8569,6 +8607,7 @@ static void pp_reset_stdmac(enum preproc_mode mode)
 
     pp_add_limits_stdmac();
 
+    pp_add_list_options_default_stdmac();
     do_predef = true;
 
     /*

doc/changes.src

@@ -133,10 +133,17 @@ It is the production version of NASM since 2025.
 \b Fix a crash when \c{-M} directives were used in response files.
 
 \b New listing option \c{-Lc} to include the contents of \c{INCBIN}
-   files.
+   files, see \k{opt-L}.
 
 \b New listing option \c{-Lt} to include the output from every
-   iteration of \c{TIMES} and \c{ALIGN} directives.
+   iteration of \c{TIMES} and \c{ALIGN} directives, see \k{opt-L}.
+
+\b The \c{%pragma list options} directive now support resetting
+   options to their command-line default, see \k{opt-L}.
+
+\b New predefined macros \c{__?LIST_OPTIONS?__} and
+   \c{__?LIST_OPTIONS_DEFAULT?__} to query the active and command-line
+   default listing options. See \k{opt-L}.
 
 
 \S{cl-3.01} Version 3.01

doc/running.src

@@ -138,24 +138,52 @@ bug reporting), and not likely to be otherwise useful:
 
 \b \c{-L!} enable \e{all} listing options including debugging ones
 
+For forward compatility reasons, an undefined flag will be
+ignored. Thus, a new flag introduced in a newer version of NASM can be
+specified without breaking older versions. Listing flags will always
+be a single alphanumeric character and are case sensitive.
+
 These options can be enabled or disabled at runtime using the
 \c{%pragma list options} directive:
 
-\c %pragma list options [+|-]flags...
+\c %pragma list options [+|-|*]{!|flags}...
+
+\c{+}, \c{-} and \c{*} adds, removes, or restores to the command-line
+default the flags that follow.
 
 For example, to turn on the \c{d} and \c{m} flags but disable the
 \c{s} flag:
 
 \c %pragma list options +dm -s
 
-The \c{+} and \c{!} shorthands available in on the command line are
+The \c{+} and \c{++} shorthands available in on the command line are
 not available when using \c{%pragma list options}; each listing option
-needs to be specified explicitly.
+needs to be specified explicitly, or \c{!} can be used to specify all
+options.
 
-For forward compatility reasons, an undefined flag will be
-ignored. Thus, a new flag introduced in a newer version of NASM can be
-specified without breaking older versions. Listing flags will always
-be a single alphanumeric character and are case sensitive.
+Spaces, quotation marks, and commas in the argument are explicitly
+ignored; thus, specifying the options as one or more quoted strings is
+valid.
+
+The built-in macros \i\c{__?LIST_OPTIONS?__} and
+\i\c{__?LIST_OPTIONS_DEFAULT?__} contain the currently active and the
+command-line default listing options, respectively, as quoted strings.
+
+To save and restore the listing options, one can use:
+
+\c %macro ...
+\c %define %%saved_list_options __?LIST_OPTIONS?__
+\c ; ... do stuff with special listing options ...
+\c %pragma list options -! +%%saved_list_options
+\c %endmacro
+
+The statement:
+
+\c %pragma list options -! +__?LIST_OPTIONS_DEFAULT?__
+
+... is exactly equivalent to ...
+
+\c %pragma list options *!
 
 \S{opt-M} The \i\c{-M} Option: Generate \i{Makefile Dependencies}
 

doc/stdmac.src

@@ -227,6 +227,20 @@ For example, if the \c{altreg} package is included (see
 
 See also the \c{%ifusable} and \c{%ifusing} directives, \k{ifusing}.
 
+
+\H{list_options_macro} \i\c{__?LIST_OPTIONS?__}: Current Listing Options
+
+Contains a quoted string with the listing options currently in
+effect. See \k{opt-L}.
+
+
+\H{list_options_default_macro} \i\c{__?LIST_OPTIONS_DEFAULT?__}:
+Default Listing Options
+
+Contains a quoted string with the listing options originally specified
+by the user on the command line.  See \k{opt-L}.
+
+
 \H{pass_macro} \i\c{__?PASS?__}: Assembly Pass
 
 The macro \c{__?PASS?__} is defined to be \c{1} on preparatory passes,