[flang][Driver] When linking with the Fortran runtime also link with libexecinfo

[brad0]

Also link with libexecinfo on FreeBSD, NetBSD, OpenBSD and DragonFly
for the backtrace functions.

[llvmbot]

@llvm/pr-subscribers-clang
@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-flang-driver

Author: Brad Smith (brad0)

Changes

Also link with libexecinfo on FreeBSD, NetBSD, OpenBSD and DragonFly
for the backtrace functions.

---

Full diff: https://github.com/llvm/llvm-project/pull/125998.diff

2 Files Affected:

• (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+5)
• (added) flang/test/Driver/backtrace.f90 (+3)

diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index c3c22a419f352a3..699aadec86dcba9 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1340,6 +1340,11 @@ void tools::addFortranRuntimeLibs(const ToolChain &TC, const ArgList &Args,
     CmdArgs.push_back("-lFortranRuntime");
     CmdArgs.push_back("-lFortranDecimal");
     addArchSpecificRPath(TC, Args, CmdArgs);
+
+    // needs libexecinfo for backtrace functions
+    if (TC.getTriple().isOSFreeBSD() || TC.getTriple().isOSNetBSD() ||
+        TC.getTriple().isOSOpenBSD() || TC.getTriple().isOSDragonFly())
+      CmdArgs.push_back("-lexecinfo");
   }
 
   // libomp needs libatomic for atomic operations if using libgcc
diff --git a/flang/test/Driver/backtrace.f90 b/flang/test/Driver/backtrace.f90
new file mode 100644
index 000000000000000..eb7f2208e5bbd4e
--- /dev/null
+++ b/flang/test/Driver/backtrace.f90
@@ -0,0 +1,3 @@
+!RUN: %flang --target=aarch64-unknown-openbsd -### %s 2>&1 | FileCheck --check-prefixes=BACKTRACE %s
+
+!BACKTRACE: -lexecinfo

[brad0]

cc @Meinersbur @tblah @dty2

[tblah]

Thanks for coming back to this @brad0

[llvm-ci]

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-4 while building clang,flang at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/14191

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: Analysis/live-stmts.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/clang -cc1 -internal-isystem /Users/buildbot/buildbot-root/aarch64-darwin/build/lib/clang/21/include -nostdsysteminc -analyze -analyzer-constraints=range -setup-static-analyzer -w -analyzer-checker=debug.DumpLiveExprs /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp 2>&1   | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/clang -cc1 -internal-isystem /Users/buildbot/buildbot-root/aarch64-darwin/build/lib/clang/21/include -nostdsysteminc -analyze -analyzer-constraints=range -setup-static-analyzer -w -analyzer-checker=debug.DumpLiveExprs /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp
�[1m/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp:239:16: �[0m�[0;1;31merror: �[0m�[1mCHECK-EMPTY: is not on the line after the previous match
�[0m// CHECK-EMPTY:
�[0;1;32m               ^
�[0m�[1m<stdin>:180:1: �[0m�[0;1;30mnote: �[0m�[1m'next' match was here
�[0m
�[0;1;32m^
�[0m�[1m<stdin>:177:1: �[0m�[0;1;30mnote: �[0m�[1mprevious match ended here
�[0m
�[0;1;32m^
�[0m�[1m<stdin>:178:1: �[0m�[0;1;30mnote: �[0m�[1mnon-matching line after previous match is here
�[0mImplicitCastExpr 0x127017f78 '_Bool' <LValueToRValue>
�[0;1;32m^
�[0m
Input file: <stdin>
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/test/Analysis/live-stmts.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
�[1m�[0m�[0;1;30m           1: �[0m�[1m�[0;1;46m �[0m
�[0;1;30m           2: �[0m�[1m�[0;1;46m�[0m[ B0 (live expressions at block exit) ]�[0;1;46m �[0m
�[0;1;32mcheck:21      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m           3: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:22      ^
�[0m�[0;1;30m           4: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:23      ^
�[0m�[0;1;30m           5: �[0m�[1m�[0;1;46m�[0m[ B1 (live expressions at block exit) ]�[0;1;46m �[0m
�[0;1;32mcheck:24      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m           6: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:25      ^
�[0m�[0;1;30m           7: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:26      ^
�[0m�[0;1;30m           8: �[0m�[1m�[0;1;46m�[0m[ B2 (live expressions at block exit) ]�[0;1;46m �[0m
�[0;1;32mcheck:27      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m           9: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:28      ^
�[0m�[0;1;30m          10: �[0m�[1m�[0;1;46m�[0mDeclRefExpr 0x1270152e0 'int' lvalue ParmVar 0x127877a70 'y' 'int'�[0;1;46m �[0m
�[0;1;32mnext:29       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m          11: �[0m�[1m�[0;1;46m�[0m �[0m
�[0;1;32mempty:30      ^
�[0m�[0;1;30m          12: �[0m�[1m�[0;1;46m�[0mDeclRefExpr 0x127015300 'int' lvalue ParmVar 0x127877af0 'z' 'int'�[0;1;46m �[0m
...