refactor the linker script

to make it more compatible with LLD. This commit contains no functional changes.

fixes #70

Overview of changes:

- Alignment checks are enabled now that rust-lld (LLD 7.0) supports the modulo
operator.

- Removed some private symbols (e.g. __foo) in favor of ADDR and SIZEOF.

- Turned .got into a NOLOAD section now that rust-lld supports it.

- Replaced `ABSOLUTE(.)` with `.` as an old LLD overlap bug seems to be gone and
ABSOLUTE seems to cause problems, like #70, on bigger programs.

- Made the linker assertion messages more uniform.

- Extended test suite to check that linking works with both rust-lld and GNU
LD.

1 files changed, 25 insertions, 0 deletions

diff --git a/cortex-m-rt/ci/script.sh b/cortex-m-rt/ci/script.sh
index 221386d..2515b8f 100644
--- a/cortex-m-rt/ci/script.sh
+++ b/cortex-m-rt/ci/script.sh
@@ -6,11 +6,13 @@ main() {
     cargo check --target $TARGET --features device
 
     local examples=(
+        alignment
         minimal
         main
         state
     )
     if [ $TRAVIS_RUST_VERSION = nightly ]; then
+        # linking with GNU LD
         for ex in "${examples[@]}"; do
             cargo rustc --target $TARGET --example $ex -- \
                   -C link-arg=-nostartfiles \
@@ -28,6 +30,29 @@ main() {
         cargo rustc --target $TARGET --example device --features device --release -- \
               -C link-arg=-nostartfiles \
               -C link-arg=-Wl,-Tlink.x
+
+        # linking with rustc's LLD
+        for ex in "${examples[@]}"; do
+            cargo rustc --target $TARGET --example $ex -- \
+                  -C linker=rust-lld \
+                  -Z linker-flavor=ld.lld \
+                  -C link-arg=-Tlink.x
+
+            cargo rustc --target $TARGET --example $ex --release -- \
+                  -C linker=rust-lld \
+                  -Z linker-flavor=ld.lld \
+                  -C link-arg=-Tlink.x
+        done
+
+        cargo rustc --target $TARGET --example device --features device -- \
+              -C linker=rust-lld \
+              -Z linker-flavor=ld.lld \
+              -C link-arg=-Tlink.x
+
+        cargo rustc --target $TARGET --example device --features device --release -- \
+              -C linker=rust-lld \
+              -Z linker-flavor=ld.lld \
+              -C link-arg=-Tlink.x
     fi
 }