Check for C++-17 header compatibility in CI (fixes #1567)

Jay Berkenbilt
1 parent 1a5c51b6
Showing 6 changed files with 49 additions and 3 deletions
CMakeLists.txt
build-scripts/build-linux
build-scripts/check-headers
include/qpdf/Pl_StdioFile.hh
job.sums
manual/release-notes.rst
@@ -169,6 +169,7 @@ endif()
 if(CXX_NEXT)
   set(CMAKE_CXX_STANDARD 23)
 else()
+  # See also build-scripts/check-headers
   set(CMAKE_CXX_STANDARD 20)
 endif()
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -18,6 +18,8 @@ for i in $(./qpdf/qpdf --show-crypto | tail -n +2); do
     env QPDF_CRYPTO_PROVIDER=$i ctest --verbose -R '^qpdf$'
 done
 cd ..
+# Perform additional tests on header files.
+./build-scripts/check-headers
 export TMPDIR=$PWD/dist-tmp
 rm -rf $TMPDIR
 ./make_dist --ci
+#!/bin/bash
+set -eo pipefail
+cd $(dirname $0)/..
+
+trap "rm -f a.cc" EXIT
+declare -a headers
+cd include
+for i in qpdf/*.hh; do
+    if [[ ! $i =~ .*auto_.* ]] && ! grep -q >/dev/null 2>&1 QPDFOBJECT_OLD_HH $i; then
+        headers+=($i)
+    fi
+done
+cd ..
+# Make sure each header file can be included in isolation and that the
+# result can be compiled with the intended version of the C++
+# standard, which may be older than one we build with internally.
+declare -a errors
+for i in "${headers[@]}"; do
+    rm -f a.cc
+    cat > a.cc <<EOF
+#include "$i"
+int main() { return 0; }
+EOF
+    echo "Checking $i"
+    if ! g++ -std=c++17 -pedantic-errors -c -Iinclude a.cc -o /dev/null; then
+        errors+=("$i doesn't compile")
+    fi
+    # Fail if any C++20 headers are included. Modern g++/clang treat
+    # these as empty if the compiler standard is too old.
+    if grep -q >/dev/null 2>&1 -E "#\s*include\s*[<\"](concepts|coroutine|compare|ranges|format|source_location|version|span|bit|numbers|barrier|latch|semaphore|stop_token|syncstream)[>\"]" "include/$i"; then
+        errors+=("$i includes a non-C++-17 standard header")
+    fi
+done
+if [[ ${#errors[@]} -gt 0 ]]; then
+    echo ""
+    echo "Some header files had errors"
+    for i in "${errors[@]}"; do
+        echo "$i"
+    done
+    exit 2
+fi
@@ -45,8 +45,6 @@ class QPDF_DLL_CLASS Pl_StdioFile: public Pipeline
   private:
     class Members;
-    ;
-
     std::unique_ptr<Members> m;
 };
 # Generated by generate_auto_job
-CMakeLists.txt 18214e276670dc8beb2ab83f789c6d94941bc92b199b353f3943024cfd41d3bc
+CMakeLists.txt 5b8566f49d7b8b96cd6f7404670f65a03851826364e52697c3a7a2206f0f3069
 generate_auto_job 8e3175a515aa8837d8a01bba0346b04b3d777d70330ba5b7d52f691316054a34
 include/qpdf/auto_job_c_att.hh 4c2b171ea00531db54720bf49a43f8b34481586ae7fb6cbf225099ee42bc5bb4
 include/qpdf/auto_job_c_copy_att.hh 50609012bff14fd82f0649185940d617d05d530cdc522185c7f3920a561ccb42
@@ -52,6 +52,10 @@ more detail.
       than ``unsigned char``) container and facilitate the efficient moving
       of its content into a `std::string``.
+  - Build fixes
+
+    - Attempt to detect if any > C++-17 changes snuck into any public
+      headers.
   - CLI Enhancements