strange test failures

[Martin Sebor <msebor at gmail dot com>]

I'm seeing failures in a few C tests that I'm not sure what to make
out of.  The tests fail due to undefined symbols while linking even
though they're not meant to link.  Among these are a number (but not
all) of the gcc.dg/divmod-[1-6]{-simode}.c tests.

  FAIL: gcc.dg/divmod-1.c (test for excess errors)

The log shows that they are being built without the -S option:

spawn -ignore SIGHUP /opt/notnfs/msebor/build/gcc-78622/gcc/xgcc 
-B/opt/notnfs/msebor/build/gcc-78622/gcc/ 
/opt/notnfs/msebor/src/gcc/gcc-78622/gcc/testsuite/gcc.dg/divmod-1.c 
-fno-diagnostics-show-caret -fdiagnostics-color=never -O2 
-fdump-tree-widening_mul-details -lm -o ./divmod-1.exe
/lib/../lib64/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
...

When I run make check-c I get these same failures in different tests.

In successful builds the logs show that the tests are only assembled
(i.e., compiled with -S), never linked.

I can reproduce this on two different x86_64 machines but so far
only with my patches to GCC (the middle end but none of these tests
or the GCC .exp files).  Is it possible that somehow my changes cause
this?  (The removal of the -S option.)  Am I missing something about
how GCC tests are run?

Thanks
Martin

PS I also see other strange errors like

RROR: tcl error sourcing 
/opt/notnfs/msebor/src/gcc/gcc-78622/gcc/testsuite/gcc.c-torture/execute/execute.exp.
ERROR: unmatched open brace in list

ERROR: tcl error sourcing 
/opt/notnfs/msebor/src/gcc/gcc-78622/gcc/testsuite/gcc.c-torture/execute/ieee/ieee.exp.
ERROR: torture-init: torture_without_loops is not empty as expected