macho: implement do_dead_strip, make subsections_by_symbols a pragma

Implement the MachO do_dead_strip directive, which sets a flag on the
corresponding section.  This as well as subsections_by_symbols are
reimplemented as pragmas; if someone uses the predefined macro they
still get the expected behavior.

However, this allows someone to write:

%pragma macho subsections_by_symbols

... and have it ignored if compiling for, say, ELF.

Also, implement the following section attributes:

      zerofill, no_dead_strip, live_support, strip_static_syms

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

1 files changed, 17 insertions, 0 deletions

diff --git a/include/nasm.h b/include/nasm.h
index 146c727b..61e56344 100644
--- a/include/nasm.h
+++ b/include/nasm.h
@@ -409,6 +409,23 @@ extern const struct preproc_ops preproc_nop;
 #define isnumchar(c)   (nasm_isalnum(c) || (c) == '_')
 
 /*
+ * inline function to skip past an identifier; returns the first character past
+ * the identifier if valid, otherwise NULL.
+ */
+static inline char *nasm_skip_identifier(const char *str)
+{
+    const char *p = str;
+
+    if (!isidstart(*p++)) {
+        p = NULL;
+    } else {
+        while (isidchar(*p++))
+            ;
+    }
+    return (char *)p;
+}
+
+/*
  * Data-type flags that get passed to listing-file routines.
  */
 enum {