[PATCH v3 1/3] Allow explicit module dependencies

[Oliver Steffen]

The build system deduces inter-module dependencies from the symbols
required and exported by the modules. This works well, except for some
rare cases where the dependency is indirect or hidden. A module might
not make use of any function of some other module, but still expect its
functionality to be available to GRUB.

To solve this, introduce a new file (currently empty) called
extra_deps.lst to track these cases manually. This file gets
processed in the same way as the (automatically generated) syminfo.lst,
making it possible to inject data into the dependency resolver.

Since *.lst files are set to be ignored by git, add an exception for
extra_deps.lst.

Additionally, introduce a new keyword for the syminfo.lst syntax:
"depends" allows specifying a module dependency directly:

    depends <module> <depdendency>...

Signed-off-by: Oliver Steffen <osteffen@redhat.com>
---
 .gitignore               | 1 +
 grub-core/Makefile.am    | 4 ++--
 grub-core/extra_deps.lst | 0
 grub-core/genmoddep.awk  | 4 ++++
 4 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 grub-core/extra_deps.lst

diff --git a/.gitignore b/.gitignore
index 11fcecf5c..4d0dfb700 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 *.img
 *.log
 *.lst
+!/grub-core/extra_deps.lst
 *.marker
 *.mod
 *.o
diff --git a/grub-core/Makefile.am b/grub-core/Makefile.am
index f0cb2f2cc..b8173f4e1 100644
--- a/grub-core/Makefile.am
+++ b/grub-core/Makefile.am
@@ -452,8 +452,8 @@ crypto.lst: $(srcdir)/lib/libgcrypt-grub/cipher/crypto.lst
 platform_DATA += crypto.lst
 CLEANFILES += crypto.lst
 
-syminfo.lst: gensyminfo.sh kernel_syms.lst $(MODULE_FILES)
-       cat kernel_syms.lst > $@.new
+syminfo.lst: gensyminfo.sh kernel_syms.lst extra_deps.lst $(MODULE_FILES)
+       cat kernel_syms.lst extra_deps.lst > $@.new
        for m in $(MODULE_FILES); do \
          sh $< $$m >> $@.new || exit 1; \
        done
diff --git a/grub-core/extra_deps.lst b/grub-core/extra_deps.lst
new file mode 100644
index 000000000..e69de29bb
diff --git a/grub-core/genmoddep.awk b/grub-core/genmoddep.awk
index 247436392..cc987a53a 100644
--- a/grub-core/genmoddep.awk
+++ b/grub-core/genmoddep.awk
@@ -31,6 +31,10 @@ BEGIN {
       printf "%s in %s is not defined\n", $3, $2 >"/dev/stderr";
       error++;
     }
+  } else if ($1 == "depends") {
+    for (i = 3; i <= NF; i++) {
+      modtab[$2] = modtab[$2] " " $i;
+    }
   }
   else {
     printf "error: %u: unrecognized input format\n", NR >"/dev/stderr";
-- 
2.41.0