[binutils-gdb] Fix build errors in with clang in gdb.compile/compile-cplus.c

[gdb-buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 678048e8079ace915052f3070b2df97bcaea58d2 ***

commit 678048e8079ace915052f3070b2df97bcaea58d2
Author:     Gary Benson <gbenson@redhat.com>
AuthorDate: Fri May 29 17:43:17 2020 +0100
Commit:     Gary Benson <gbenson@redhat.com>
CommitDate: Fri May 29 17:43:17 2020 +0100

    Fix build errors in with clang in gdb.compile/compile-cplus.c
    
    Clang fails to compile the file, with the following error:
      fatal error: 'iostream' file not found
    
    This prevents the following testcase from executing:
      gdb.compile/compile-cplus.exp
    
    The testcase sets additional_flags when building with GCC, which
    this commit causes to also be set when building with clang.  This
    makes the testcase fail to build with a different error:
      warning: treating 'c' input as 'c++' when in C++ mode, this behavior
      is deprecated [-Wdeprecated]
    so this commit adds -Wno-deprecated in two places to sidestep this.
    Note that, while allowing the testcase to build, this commit reveals
    failures when the testsuite is built using clang.
    
    gdb/testsuite/ChangeLog:
    
            * gdb.compile/compile-cplus.exp (additional_flags): Also
            set when building with clang.
            (additional_flags, srcfilesoptions): Pass -Wno-deprecated
            when building with clang.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 667dbfddec..d4e7220b32 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2020-05-29  Gary Benson <gbenson@redhat.com>
+
+	* gdb.compile/compile-cplus.exp (additional_flags): Also
+	set when building with clang.
+	(additional_flags, srcfilesoptions): Pass -Wno-deprecated
+	when building with clang.
+
 2020-05-29  Gary Benson <gbenson@redhat.com>
 
 	* gdb.arch/i386-avx.exp (additional_flags): Also set when
diff --git a/gdb/testsuite/gdb.compile/compile-cplus.exp b/gdb/testsuite/gdb.compile/compile-cplus.exp
index cca5b20520..85b2f20a8f 100644
--- a/gdb/testsuite/gdb.compile/compile-cplus.exp
+++ b/gdb/testsuite/gdb.compile/compile-cplus.exp
@@ -19,11 +19,16 @@ standard_testfile .c compile-shlib.c compile-constvar.S compile-nodebug.c
 
 get_compiler_info
 set options {}
-if [test_compiler_info gcc*] {
+if { [test_compiler_info gcc*] || [test_compiler_info clang*] } {
     lappend options additional_flags=-g3
     lappend options additional_flags=-std=gnu++11
     lappend options c++
 }
+if [test_compiler_info clang*] {
+    # Treating C input as C++ is deprecated in Clang, so
+    # the build will fail without disabling -Wdeprecated.
+    lappend options additional_flags=-Wno-deprecated
+}
 
 if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
     verbose "Skipping x86_64 LOC_CONST test."
@@ -34,7 +39,13 @@ set srcfilesoptions [list ${srcfile} ${options}]
 if { $srcfile3 != "" } {
     lappend srcfilesoptions $srcfile3 ${options}
 }
-lappend srcfilesoptions $srcfile4 "nodebug c++"
+set srcfile4options "nodebug c++"
+if [test_compiler_info clang*] {
+    # Treating C input as C++ is deprecated in Clang, so
+    # the build will fail without disabling -Wdeprecated.
+    set srcfile4options "$srcfile4options additional_flags=-Wno-deprecated"
+}
+lappend srcfilesoptions $srcfile4 $srcfile4options
 if { [eval build_executable_from_specs ${testfile}.exp $testfile {$options} ${srcfilesoptions}] } {
     return -1
 }