nasm: fix the combination -E -MD, handle -MD without a filename

-E -MD should work and output a dependency file.
-MD can be used without a filename; there is a default filename or
-\c{-MF} can be used.

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

2 files changed, 15 insertions, 0 deletions

diff --git a/doc/changes.src b/doc/changes.src
index ffbcda0d..1bc8f2aa 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -25,6 +25,12 @@ or hexadecimal floating-point having at least 32, 11, or 8 mantissa
 digits could produce slightly incorrect results under very specific
 conditions.
 
+\b Support \c{-MD} without a filename, for \c{gcc}
+compatibility. \c{-MF} can be used to set the dependencies output
+filename. See \k{opt-MD}.
+
+\b Fix \c{-E} in combination with \c{-MD}. See \k{opt-E}.
+
 \S{cl-2.14} Version 2.14
 
 \b Changed \c{-I} option semantics by adding a trailing path separator
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src
index ebbd29b3..f1abc507 100644
--- a/doc/nasmdoc.src
+++ b/doc/nasmdoc.src
@@ -496,6 +496,15 @@ updated dependencies with every assembly session.  For example:
 
 \c nasm -f elf -o myfile.o -MD myfile.dep myfile.asm
 
+If the argument after \c{-MD} is an option rather than a filename,
+then the output filename is the first applicable one of:
+
+\b the filename set in the \c{-MF} option;
+
+\b the output filename from the \c{-o} option with \c{.d} appended;
+
+\b the input filename with the extension set to \c{.d}.
+
 
 \S{opt-MT} The \i\c{-MT} Option: Dependency Target Name