Add to CI per-commit checking of ABI stability using abi-dumper and l…

…ibabigail

for GCCs 7 and 9 in C++ 14 and C++ 17 respectively.

.github/workflows/abi_stability.yml

@@ -0,0 +1,57 @@
+name: ABIStability
+
+on:
+  push:
+    branches:
+    - develop
+    - master
+  pull_request:
+  schedule:
+  - cron: '0 0 1 * *'
+
+jobs:
+  abi_stability:
+    name: "ABI stability"
+    runs-on: ubuntu-20.04
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install abi-compliance-checker and abigail tools
+      shell: bash
+      run: |
+       sudo apt-get -y install abi-dumper abi-compliance-checker abigail-tools g++-7 g++-9
+
+    - name: Validate ABI compatibility (abi-dumper)
+      if: success() || failure()
+      shell: bash
+      run: |
+       cd abi-compliance
+       ./check-abi.sh 2.2
+       
+    - name: Validate ABI compatibility (abigail)
+      if: success() || failure()
+      shell: bash
+      run: |
+       cd abi-compliance
+       ./check-abigail.sh 2.2
+       
+#    - name: Validate API + ABI compatibility (abi-compliance-checker)
+#      if: success() || failure()
+#      shell: bash
+#      run: |
+#       cd abi-compliance
+#       ./check-api-abi.sh 2.2
+
+    - name: Upload ABI stability reports
+      if: success() || failure()
+      uses: actions/upload-artifact@v2
+      with:
+        name: ABI stability report (GCC 7 with C++ 14)
+        path: abi-compliance/compat-reports/Outcome/2.2-gcc7-cxx14_to_test-gcc7-cxx14/compat_report.html
+      with:
+        name: ABI stability report (GCC 9 with C++ 17)
+        path: abi-compliance/compat-reports/Outcome/2.2-gcc9-cxx17_to_test-gcc9-cxx17/compat_report.html
+#      with:
+#        name: API + ABI stability report (GCC 9 with C++ 17)
+#        path: abi-compliance/compat-reports/Outcome/2.2-gcc7-cxx14_to_X/compat_report.html

abi-compliance/CMakeLists.txt

@@ -7,3 +7,7 @@ add_subdirectory(.. outcome EXCLUDE_FROM_ALL)
 add_library(outcome-abi-lib-${LABEL} SHARED "src/main.cpp")
 target_link_libraries(outcome-abi-lib-${LABEL} PUBLIC outcome::hl)
 add_dependencies(outcome-abi-lib-${LABEL} outcome_hl-pp-abi)
+target_compile_definitions(outcome-abi-lib-${LABEL} PUBLIC OUTCOME_DISABLE_ABI_PERMUTATION=1)
+if(NOT MSVC)
+  target_compile_options(outcome-abi-lib-${LABEL} PUBLIC -Og)
+endif()

abi-compliance/Readme.md

@@ -1,7 +1,7 @@
 # Notes on the API and ABI stability checking
 
-Outcome is a header only library with a very simple Application Binary
-Interface (ABI). Therefore, your shared library with functions which consume
+Outcome is a header only library with a very simple data type layout designed
+for strong ABI. Therefore, your shared library with functions which consume
 and return Outcomes ought to be perfectly binary stable in the pure sense of
 that Outcome's core `result<T, E>` and `outcome<T, E, P>` object layout will
 not change, no matter what changes occur in Outcome in the future.
@@ -20,29 +20,43 @@ stability. These are what are checked per CI commit:
 <dl>
   <dt>2.2-gcc7-cxx14</dt>
   <dd>This is when compiled under the C++ 14 standard by GCC 7.5.</dd>
+  <dt>2.2-gcc9-cxx17</dt>
+  <dd>This is when compiled under the C++ 17 standard by GCC 9.3.</dd>
 </dl>
 
 ## Prerequisites for using this directory:
 
 1. GCC 7.5 with libstdc++.
-2. A recent Linux.
+2. GCC 9.3 with libstdc++.
+3. Ubuntu 20.04 LTS.
 
-### Prerequisites if you want to check only ABI:
+### Prerequisites if you want to check only ABI (abi-dumper):
 
-1. Some edition of `abi-dumper` (one usually comes in your Linux
-package repos).
-2. Some edition of `abi-compliance-checker` (one usually comes in your Linux
-package repos).
+1. `abi-dumper`
+2. `abi-compliance-checker`
 
-Run `./check-abi.sh abi_dumps/Outcome/<ABIVER>/binary_only.dump` to check that
+Run `./check-abi.sh 2.2` to check that
 the current Outcome's ABI is compatible with the stored ABI. A HTML report
 will be generated by the `abi-compliance-checker` tool useful for displaying
 in CI servers and/or emailing to team members.
 
+If you see breakage in this tool, please do report such ABI breakages
+to https://github.com/ned14/outcome/issues.
+
+### Prerequisites if you want to check only ABI (libabigail):
+
+1. `abigail-tools`
+
+Run `./check-abigail.sh 2.2` to check that
+the current Outcome's ABI is compatible with the stored ABI.
+
+If you see breakage in this tool, please do report such ABI breakages
+to https://github.com/ned14/outcome/issues.
+
 ### Prerequisites if you want to check ABI and API:
 
-1. A new enough ABI compliance checker to work with GCC 7 (https://github.com/lvc/abi-compliance-checker)
-and all its prerequisites.
+1. `abi-dumper`
+2. `abi-compliance-checker`
 
 Run `./check-api-abi.sh 2.2` to check that the current Outcome's ABI and API
 is compatible with the stored ABI. A HTML report
@@ -53,10 +67,3 @@ As users familiar with this tool will know, this form of the tool is
 somewhat prone to false positives. Every failure needs to be carefully
 studied to determine if it is actually a problem or not.
 
-Alternatively run `./check-abi.sh 2.2` to check that the current Outcome's ABI
-is compatible with the stored ABI. A HTML report
-will be generated by the `abi-compliance-checker` tool useful for displaying
-in CI servers and/or emailing to team members.
-
-If you see breakage in this latter tool, please do report such ABI breakages
-to https://github.com/ned14/outcome/issues.