Document problems with linking GCC-compiled libraries with a compiler

other than GCC.

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 513e3fcaec43ccf883ba70f8bcfcd48f5e532297..28e9596fceb5d4e2af573582ec3b237dd92d8247 100644 (file)
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -27,6 +27,19 @@ the script).
 Note that this problem does not pertain to the MS-Windows port of
 Emacs, since it doesn't use the preprocessor to generate Makefiles.
 
+* Building Emacs with a system compiler fails during link stage.
+
+This can happen if some of the libraries linked into Emacs were built
+with GCC, but Emacs itself is being linked with a compiler other than
+GCC.  Object files compiled with GCC might need some helper functions
+from libgcc.a, the library which comes with GCC, but the system
+compiler does not instruct the linker to search libgcc.a during the
+link stage.
+
+A solution is to link with GCC, like this:
+
+       make CC=gcc
+
 * Building the MS-Windows port with Cygwin GCC can fail.
 
 Emacs may not build using recent Cygwin builds of GCC, such as Cygwin