Apply H.J. Lu's patch to pass -mshstk to the compiler when Intel CET is

enabled. CMake version invented by PH, but only tested on non-CET system.

CMakeLists.txt

@@ -92,6 +92,7 @@
 #            library versioning.
 # 2020-04-25 Carlo added function check for mkostemp used in ProtExecAllocator
 # 2020-04-28 PH added function check for memfd_create based on Carlo's patch
+# 2020-05-25 PH added a check for Intel CET
 
 PROJECT(PCRE2 C)
 
@@ -146,6 +147,24 @@ CHECK_C_SOURCE_COMPILES(
 )
 set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
 
+# Check whether Intel CET is enabled, and if so, adjust compiler flags. This
+# code was written by PH, trying to imitate the logic from the autotools 
+# configuration.
+
+CHECK_C_SOURCE_COMPILES(
+  "#ifndef __CET__
+   #error CET is not enabled
+   #endif
+   int main() { return 0; }"
+  INTEL_CET_ENABLED
+)
+
+IF (INTEL_CET_ENABLED)
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mshstk")
+ENDIF(INTEL_CET_ENABLED)   
+        
+
+
 # User-configurable options
 #
 # Note: CMakeSetup displays these in alphabetical order, regardless of

ChangeLog

@@ -1,6 +1,15 @@
 Change Log for PCRE2
 --------------------
 
+Version 10.36-RC1 25-May-2020
+-----------------------------
+
+1. Add CET_CFLAGS so that when Intel CET is enabled, pass -mshstk to
+compiler. This fixes https://bugs.exim.org/show_bug.cgi?id=2578. Patch for 
+Makefile.am and configure.ac by H.J. Lu. Equivalent patch for CMakeLists.txt 
+invented by PH.
+
+
 Version 10.35 09-May-2020
 ---------------------------
 

Makefile.am

@@ -391,6 +391,7 @@ nodist_libpcre2_8_la_SOURCES = \
 libpcre2_8_la_CFLAGS = \
   -DPCRE2_CODE_UNIT_WIDTH=8 \
   $(VISIBILITY_CFLAGS) \
+  $(CET_CFLAGS) \
   $(AM_CFLAGS)
 libpcre2_8_la_LIBADD =
 endif # WITH_PCRE2_8

configure.ac

@@ -1006,6 +1006,21 @@ fi # enable_coverage
 
 AM_CONDITIONAL([WITH_GCOV],[test "x$enable_coverage" = "xyes"])
 
+AC_MSG_CHECKING([whether Intel CET is enabled])
+AC_LANG_PUSH([C])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,
+                   [[#ifndef __CET__
+# error CET is not enabled
+#endif]])],
+                   [pcre2_cc_cv_intel_cet_enabled=yes],
+                   [pcre2_cc_cv_intel_cet_enabled=no])
+AC_MSG_RESULT([$pcre2_cc_cv_intel_cet_enabled])
+if test "$pcre2_cc_cv_intel_cet_enabled" = yes; then
+  CET_CFLAGS="-mshstk"
+  AC_SUBST([CET_CFLAGS])
+fi
+AC_LANG_POP([C])
+
 # Produce these files, in addition to config.h.
 AC_CONFIG_FILES(
 	Makefile