re PR driver/16118 (Preprocessed source error with -xf77-cpp-input)

	PR driver/16118
	* doc/invoke.texi: Document the interaction between -save-temps
	and -x.

From-SVN: r92658

gcc/ChangeLog

+2004-12-27  Roger Sayle  <roger@eyesopen.com>
+
+	PR driver/16118
+	* doc/invoke.texi: Document the interaction between -save-temps
+	and -x.
+
 2004-12-27  David Edelsohn  <edelsohn@gnu.org>
 
 	* config/rs6000/rs6000.c (rs6000_eliminate_indexed_memrefs):

gcc/doc/invoke.texi

@@ -3891,6 +3891,12 @@ compiling @file{foo.c} with @samp{-c -save-temps} would produce files
 preprocessed @file{foo.i} output file even though the compiler now
 normally uses an integrated preprocessor.
 
+When used in combination with the @option{-x} command line option,
+@option{-save-temps} is sensible enough to avoid over writing an
+input source file with the same extension as an intermediate file.
+The corresponding intermediate file may be obtained by renaming the
+source file before using @option{-save-temps}.
+
 @item -time
 @opindex time
 Report the CPU time taken by each subprocess in the compilation