Makefile: render compatible with some GNU make versions (revert #12646)

[dhebbeker]

Summary of changes

Revert "Fixed problem with overlong command line."

This reverts commit dd02ac0.

This change is needed because it introduced two errors, reported by @vmedcy in #12646 (comment)

• a closing bracket is missing
• it does not run with some version of GNU make (see Makefile: fix for overlong command line #12646 (comment))

Impact of changes

Migration actions required

Documentation

None

---

Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

---

Test results

[] No Tests required for this change (E.g docs only update)
[] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

Tested with

• (unmodified) mbed 1.10.2.
• GNU Make 4.2.1 Built for x86_64-pc-linux-gnu

Test unimpeded Makefile

Tests Makefile which are produced by official release (do not include the erroneous changes).

mbed import mbed-os-example-blinky
cd mbed-os-example-blinky/
mbed export -m K64F -i eclipse_gcc_arm
make

===== bin file ready to flash: BUILD/mbed-os-example-blinky.bin =====

✔️

Test bad version

Tests Makefile which would be produced by dd02ac0.

mbed import mbed-os-example-blinky
cd mbed-os-example-blinky/
mbed export -m K64F -i eclipse_gcc_arm

Apply patch to Makefile:

-	+@echo "$(filter %.o, $^)" > .link_options.txt
+	$(file > .link_options.txt,$(filter %.o, $^)

And then

make

mbed-os-example-blinky/Makefile:1823: *** unterminated call to function 'file': missing ')'.  Stop.
make: *** [Makefile:26: all] Error 2

❌

Test version incompatible to GNU make 3.8.1

Tests Makefile based on dd02ac0 with corrected missing brace.

mbed import mbed-os-example-blinky
cd mbed-os-example-blinky/
mbed export -m K64F -i eclipse_gcc_arm

Apply patch to Makefile:

-	+@echo "$(filter %.o, $^)" > .link_options.txt
+	$(file > .link_options.txt,$(filter %.o, $^))

And then

make

===== bin file ready to flash: BUILD/mbed-os-example-blinky.bin =====

✔️ (with GNU make 4.2.1)

---

Reviewers

• @vmedcy (reported error)

---

[ciarmcom]

@dhebbeker, thank you for your changes.
@vmedcy @ARMmbed/mbed-os-tools @ARMmbed/mbed-os-maintainers please review.

[dhebbeker]

The linking recipe in the version a8a21d3 using $(file > $@.in, $(filter %.o, $^)):

• works with GNU Make 4.2.1 Built for x86_64-pc-linux-gnu ✔️
• works with GNU Make 4.3 Built for Windows32 (mingw32-make) even with long object file lists ✔️
• does not work with with GNU Make 3.81 ❌ (did not test it myself)

The linking recipe in the version 26043e5 using +@echo "$(filter %.o, $^)" > .link_options.txt:

• does not work with GNU Make 4.3 Built for Windows32 (mingw32-make) with long object file lists ❌ (maybe related: Problem with Makefile.tmpl #10943 (comment), Exporting to Makefile fails to build on Windows due to command line limit being exceeded #9140, Exporting to Makefile fails to build on Windows #6335)

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 7 of 7 test jobs passed
Build number : 1
Build artifacts