Improve gendef.pl diagnostic on failure to open sym file

adunstan · adunstan · commit d5fb450aab74 · 2017-10-26T10:17:18.000-04:00
There have been numerous buildfarm failures but the diagnostic is
currently silent about the reason for failure to open the file. Let's
see if we can get to the bottom of it.

Backpatch to all live branches.
diff --git a/src/tools/msvc/gendef.pl b/src/tools/msvc/gendef.pl
@@ -27,7 +27,7 @@
 	print ".";
 	system("dumpbin /symbols /out:symbols.out $_ >NUL")
 	  && die "Could not call dumpbin";
-	open(F, "<symbols.out") || die "Could not open symbols.out for $_\n";
+	open(F, "<symbols.out") || die "Could not open symbols.out for $_: $!\n";
 	while (<F>)
 	{
 		s/\(\)//g;

Original file line number	Diff line number	Diff line change
`@@ -27,7 +27,7 @@`
`27`	`27`	`print ".";`
`28`	`28`	`system("dumpbin /symbols /out:symbols.out $_ >NUL")`
`29`	`29`	`&& die "Could not call dumpbin";`
`30`		`- open(F, "<symbols.out") \|\| die "Could not open symbols.out for $_\n";`
	`30`	`+ open(F, "<symbols.out") \|\| die "Could not open symbols.out for $_: $!\n";`
`31`	`31`	`while (<F>)`
`32`	`32`	`{`
`33`	`33`	`s/\(\)//g;`