Enable compilation with C90 compilers

* configure.ac: Try compiling Guile headers: they don't work with C90.
* maintMakefile: Simplify config checks via target-specific variables.
* src/makeint.h: Use ATTRIBUTE rather than defining __attribute__,
as that causes compile issues with system headers.
(ENUM_BITFIELD): Don't use enum bitfields in ANSI mode.
* src/main.c: Use ATTRIBUTE instead of __attribute__.
* src/job.h: Ditto.
* src/file.c: Don't define variables inside for loops.
* src/rule.c: Ditto.
* src/dep.h (SI): Only use static inline in non-ANSI mode.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/file.c b/src/file.c
index 2f1425e6..a979ca55 100644
--- a/src/file.c
+++ b/src/file.c
@@ -640,9 +640,10 @@ expand_deps (struct file *f)
 struct dep *
 expand_extra_prereqs (const struct variable *extra)
 {
+  struct dep *d;
   struct dep *prereqs = extra ? split_prereqs (variable_expand (extra->value)) : NULL;
 
-  for (struct dep *d = prereqs; d; d = d->next)
+  for (d = prereqs; d; d = d->next)
     {
       d->file = lookup_file (d->name);
       if (!d->file)