testsuite: Clean up dynlib support predicates

Previously it was unclear whether req_shared_libs should require:

 * that the platform supports dynamic library loading,
 * that GHC supports dynamic linking of Haskell code, or
 * that the dyn way libraries were built

Clarify by splitting the predicate into two:

 * `req_dynamic_lib_support` demands that the platform support dynamic
   linking
 * `req_dynamic_hs` demands that the GHC support dynamic linking of
   Haskell code on the target platform

Naturally `req_dynamic_hs` cannot be true unless
`req_dynamic_lib_support` is also true.

18 files changed, 83 insertions, 44 deletions

diff --git a/testsuite/config/ghc b/testsuite/config/ghc
index 6d90e83397..aed4c22fb0 100644
--- a/testsuite/config/ghc
+++ b/testsuite/config/ghc
@@ -53,11 +53,12 @@ if ghc_with_threaded_rts:
             config.run_ways.append('nonmoving_thr')
 
 if ghc_with_dynamic_rts:
-    config.have_shared_libs = True
-
-if ghc_with_dynamic_rts:
+    config.supports_dynamic_libs = True
     config.run_ways.append('dyn')
 
+if windows:
+    config.supports_dynamic_hs = False
+
 if (config.have_profiling and ghc_with_threaded_rts):
     config.run_ways.append('profthreaded')
 
diff --git a/testsuite/driver/runtests.py b/testsuite/driver/runtests.py
index 98d6c134b9..2c76661184 100644
--- a/testsuite/driver/runtests.py
+++ b/testsuite/driver/runtests.py
@@ -42,6 +42,7 @@ ghc_env['TERM'] = 'vt100'
 
 global config
 config = getConfig() # get it from testglobals
+config.validate()
 
 def signal_handler(signal, frame):
     stopNow()
diff --git a/testsuite/driver/testglobals.py b/testsuite/driver/testglobals.py
index f52aec281c..adb2109923 100644
--- a/testsuite/driver/testglobals.py
+++ b/testsuite/driver/testglobals.py
@@ -134,8 +134,16 @@ class TestConfig:
         # Do we have interpreter support?
         self.have_interp = False
 
-        # Do we have shared libraries?
-        self.have_shared_libs = False
+        # Does the platform support loading of dynamic shared libraries? e.g.
+        # some musl-based environments do not.
+        self.supports_dynamic_libs = True
+
+        # Does GHC support dynamic linking of Haskell objects (i.e. the dynamic
+        # way)?
+        self.supports_dynamic_hs = True
+
+        # Is the compiler dynamically linked?
+        self.ghc_dynamic = False
 
         # Do we have SMP support?
         self.have_smp = False
@@ -152,9 +160,6 @@ class TestConfig:
         # Are we testing an in-tree compiler?
         self.in_tree_compiler = True
 
-        # Is the compiler dynamically linked?
-        self.ghc_dynamic = False
-
         # Are we running in a ThreadSanitizer-instrumented build?
         self.have_thread_sanitizer = False
 
@@ -205,6 +210,15 @@ class TestConfig:
         # I have no idea what this does
         self.package_conf_cache_file = None # type: Optional[Path]
 
+    def validate(self) -> None:
+        """ Check the TestConfig for self-consistency """
+        def assert_implies(a: bool, b: bool):
+            if a:
+                assert(b)
+
+        assert_implies(self.supports_dynamic_hs, self.supports_dynamic_libs)
+        assert_implies(self.have_dynamic, self.supports_dynamic_hs)
+        assert_implies(self.ghc_dynamic, self.have_dynamic)
 
 global config
 config = TestConfig()
diff --git a/testsuite/driver/testlib.py b/testsuite/driver/testlib.py
index 1a12f5c086..3202bab65c 100644
--- a/testsuite/driver/testlib.py
+++ b/testsuite/driver/testlib.py
@@ -206,8 +206,20 @@ def req_profiling( name, opts ):
     if not config.have_profiling:
         opts.expect = 'fail'
 
-def req_shared_libs( name, opts ):
-    if not config.have_shared_libs:
+def req_dynamic_lib_support( name, opts ):
+    '''
+    Require that the platform have shared object support (N.B. this doesn't
+    necessary imply that GHC supports the dynamic way).
+    '''
+    if not config.supports_dynamic_libs:
+        opts.expect = 'fail'
+
+def req_dynamic_hs( name, opts ):
+    '''
+    Require that the GHC supports dynamic linking of Haskell objects on the
+    platform
+    '''
+    if not config.supports_dynamic_hs:
         opts.expect = 'fail'
 
 def req_interp( name, opts ):
@@ -571,6 +583,7 @@ def have_ncg( ) -> bool:
     return config.have_ncg
 
 def have_dynamic( ) -> bool:
+    ''' Were libraries built in the dynamic way? '''
     return config.have_dynamic
 
 def have_profiling( ) -> bool:
diff --git a/testsuite/tests/cabal/cabal01/all.T b/testsuite/tests/cabal/cabal01/all.T
index 9bf2eb13d5..4a17490f18 100644
--- a/testsuite/tests/cabal/cabal01/all.T
+++ b/testsuite/tests/cabal/cabal01/all.T
@@ -8,7 +8,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if config.have_shared_libs:
+if config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'
diff --git a/testsuite/tests/cabal/cabal04/all.T b/testsuite/tests/cabal/cabal04/all.T
index 3a4756026a..d84acf98b3 100644
--- a/testsuite/tests/cabal/cabal04/all.T
+++ b/testsuite/tests/cabal/cabal04/all.T
@@ -8,7 +8,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if not config.compiler_profiled and config.have_shared_libs:
+if not config.compiler_profiled and config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'
diff --git a/testsuite/tests/driver/T20348/all.T b/testsuite/tests/driver/T20348/all.T
index cd888b0105..935c8efa8c 100644
--- a/testsuite/tests/driver/T20348/all.T
+++ b/testsuite/tests/driver/T20348/all.T
@@ -1,2 +1,3 @@
-test('T20348', [extra_files(['A.hs']),
-                when(opsys('mingw32'), skip)], makefile_test, [])
+# N.B. this package requires a dynamically-linked ghc-bin, since it assumes
+# that TH evaluation will build dynamic objects.
+test('T20348', [extra_files(['A.hs']), unless(have_dynamic(), skip)], makefile_test, [])
diff --git a/testsuite/tests/driver/recompChangedPackage/all.T b/testsuite/tests/driver/recompChangedPackage/all.T
index 8acd1655b9..f08a2534f6 100644
--- a/testsuite/tests/driver/recompChangedPackage/all.T
+++ b/testsuite/tests/driver/recompChangedPackage/all.T
@@ -8,7 +8,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if not config.compiler_profiled and config.have_shared_libs:
+if not config.compiler_profiled and config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'
diff --git a/testsuite/tests/driver/recompPluginPackage/all.T b/testsuite/tests/driver/recompPluginPackage/all.T
index ea6cce4baa..08271d9c46 100644
--- a/testsuite/tests/driver/recompPluginPackage/all.T
+++ b/testsuite/tests/driver/recompPluginPackage/all.T
@@ -8,7 +8,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if not config.compiler_profiled and config.have_shared_libs:
+if not config.compiler_profiled and config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'
diff --git a/testsuite/tests/driver/recompTHpackage/all.T b/testsuite/tests/driver/recompTHpackage/all.T
index 6e2826300c..78de429b70 100644
--- a/testsuite/tests/driver/recompTHpackage/all.T
+++ b/testsuite/tests/driver/recompTHpackage/all.T
@@ -8,7 +8,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if not config.compiler_profiled and config.have_shared_libs:
+if not config.compiler_profiled and config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'
diff --git a/testsuite/tests/dynlibs/Makefile b/testsuite/tests/dynlibs/Makefile
index 19009605ea..3de7571f27 100644
--- a/testsuite/tests/dynlibs/Makefile
+++ b/testsuite/tests/dynlibs/Makefile
@@ -67,9 +67,9 @@ T18072:
 	$(RM) -rf T18072/
 	mkdir T18072
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072 \
-    -dynamic -fPIC -c T18072.hs
+      -dynamic -fPIC -c T18072.hs
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072 \
-    -dynamic -shared -flink-rts T18072/T18072.o -o T18072/T18072.so
+      -dynamic -shared -flink-rts T18072/T18072.o -o T18072/T18072.so
 	ldd T18072/T18072.so | grep libHSrts >/dev/null
 
 .PHONY: T18072debug
@@ -77,9 +77,9 @@ T18072debug:
 	$(RM) -rf T18072debug/
 	mkdir T18072debug
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072debug \
-    -dynamic -fPIC -c T18072.hs
+      -dynamic -fPIC -c T18072.hs
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072debug \
-    -dynamic -shared -flink-rts -debug T18072debug/T18072.o -o T18072debug/T18072.so
+      -dynamic -shared -flink-rts -debug T18072debug/T18072.o -o T18072debug/T18072.so
 	ldd T18072debug/T18072.so | grep libHSrts | grep _debug >/dev/null
 
 .PHONY: T18072static
@@ -87,7 +87,7 @@ T18072static:
 	$(RM) -rf T18072static/
 	mkdir T18072static
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072static \
-    -c T18072.hs
+      -c T18072.hs
 	'$(TEST_HC)' $(filter-out -rtsopts,$(TEST_HC_OPTS)) -v0 -outputdir T18072static \
-    -staticlib -fno-link-rts T18072static/T18072.o -o T18072static/T18072.a
+      -staticlib -fno-link-rts T18072static/T18072.o -o T18072static/T18072.a
 	ar t T18072static/T18072.a | grep RtsSymbols.o > /dev/null && exit 1 || exit 0
diff --git a/testsuite/tests/dynlibs/T19350/all.T b/testsuite/tests/dynlibs/T19350/all.T
index c8915bde1f..19a34edfdb 100644
--- a/testsuite/tests/dynlibs/T19350/all.T
+++ b/testsuite/tests/dynlibs/T19350/all.T
@@ -13,4 +13,4 @@
 # into libhello.
 #
 
-test('T19350', [req_shared_libs, expect_broken(19350), extra_files(['clib', 'lib'])], makefile_test, [])
+test('T19350', [req_dynamic_lib_support, expect_broken(19350), extra_files(['clib', 'lib'])], makefile_test, [])
diff --git a/testsuite/tests/dynlibs/all.T b/testsuite/tests/dynlibs/all.T
index 622bcab6a7..569962761a 100644
--- a/testsuite/tests/dynlibs/all.T
+++ b/testsuite/tests/dynlibs/all.T
@@ -1,24 +1,31 @@
 test('T3807',
-    [req_shared_libs,
-     when(have_thread_sanitizer(), expect_broken(18883)),
-     when(opsys('mingw32'),
-     skip)], makefile_test, [])
+     [unless(have_dynamic(), skip),
+      when(have_thread_sanitizer(), expect_broken(18883))],
+    makefile_test, [])
 
-test('T4464', [req_shared_libs, unless(opsys('mingw32'), skip)], makefile_test, [])
+test('T4464', [req_dynamic_hs, unless(opsys('mingw32'), skip)], makefile_test, [])
 
-test('T5373', [req_shared_libs], makefile_test, [])
+test('T5373', [unless(have_dynamic(), skip)], makefile_test, [])
 
 # It's not clear exactly what platforms we can expect this to succeed on.
 test('T13702',
      [when(have_thread_sanitizer(), expect_broken(18884)),
-      req_shared_libs, unless(opsys('linux'), skip)],
+      unless(have_dynamic(), skip),
+      unless(opsys('linux'), skip)],
      makefile_test, [])
 
-# test that -shared and -flink-rts actually links the rts
-test('T18072', [req_shared_libs, unless(opsys('linux'), skip)], makefile_test, [])
+# test that -shared and -flink-rts actually links the RTS
+test('T18072', [unless(have_dynamic(), skip), unless(opsys('linux'), skip)], makefile_test, [])
 
 # test that -shared and -flink-rts respects alternative RTS flavours
-test('T18072debug', [extra_files(['T18072.hs']), req_shared_libs, unless(opsys('linux'), skip)], makefile_test, [])
+test('T18072debug',
+     [unless(have_dynamic(), skip),
+      extra_files(['T18072.hs']),
+      unless(opsys('linux'), skip)],
+     makefile_test, [])
 
-# check that -staticlib and -fno-link-rts results in an archive without the RTR library 
-test('T18072static', [extra_files(['T18072.hs']), unless(opsys('linux'), skip)], makefile_test, [])
+# check that -staticlib and -fno-link-rts results in an archive without the RTS library 
+test('T18072static',
+     [extra_files(['T18072.hs']),
+      unless(opsys('linux'), skip)],
+     makefile_test, [])
diff --git a/testsuite/tests/ghci/linking/all.T b/testsuite/tests/ghci/linking/all.T
index 655941d145..574ff9308c 100644
--- a/testsuite/tests/ghci/linking/all.T
+++ b/testsuite/tests/ghci/linking/all.T
@@ -8,7 +8,7 @@ test('ghcilink001',
 test('ghcilink002', [extra_files(['TestLink.hs', 'f.c']),
                      when(unregisterised(), fragile(16085)),
                      unless(doing_ghci, skip),
-                     req_shared_libs],
+                     unless(have_dynamic(), skip)],
      makefile_test, ['ghcilink002'])
 
 test('ghcilink003',
@@ -32,7 +32,7 @@ test('ghcilink005',
      [extra_files(['TestLink.hs', 'f.c']),
       when(unregisterised(), fragile(16085)),
       unless(doing_ghci, skip),
-      req_shared_libs],
+      req_dynamic_lib_support],
      makefile_test, ['ghcilink005'])
 
 test('ghcilink006',
diff --git a/testsuite/tests/ghci/linking/dyn/all.T b/testsuite/tests/ghci/linking/dyn/all.T
index e2593ded9b..0092f7febe 100644
--- a/testsuite/tests/ghci/linking/dyn/all.T
+++ b/testsuite/tests/ghci/linking/dyn/all.T
@@ -1,4 +1,4 @@
-setTestOpts(req_shared_libs)
+setTestOpts(req_dynamic_lib_support)
 
 test('load_short_name', [extra_files(['A.c']),
                          unless(doing_ghci, skip)],
diff --git a/testsuite/tests/profiling/should_compile/all.T b/testsuite/tests/profiling/should_compile/all.T
index d91cf9c666..a6a6d50c7c 100644
--- a/testsuite/tests/profiling/should_compile/all.T
+++ b/testsuite/tests/profiling/should_compile/all.T
@@ -6,8 +6,7 @@ test('prof002', [only_ways(['normal']), req_profiling], compile_and_run, ['-prof
 test('T2410', [only_ways(['normal']), req_profiling], compile, ['-O2 -prof -fprof-cafs'])
 test('T5889', [only_ways(['normal']), req_profiling, extra_files(['T5889/A.hs', 'T5889/B.hs'])], multimod_compile, ['A B', '-O -prof -fno-prof-count-entries -v0'])
 test('T12790', [only_ways(['normal']), req_profiling], compile, ['-O -prof'])
-# -dynamic-too not supported on Windows
-test('T14931', [when(opsys('mingw32'), skip), only_ways(['normal']), req_profiling, req_shared_libs],
+test('T14931', [only_ways(['normal']), req_profiling, unless(have_dynamic(), skip)],
      makefile_test, ['T14931'])
 test('T15108', [only_ways(['normal']), req_profiling], compile, ['-O -prof -fprof-auto'])
 test('T19894', [only_ways(['normal']), req_profiling, extra_files(['T19894'])], multimod_compile, ['Main', '-v0 -O2 -prof -fprof-auto -iT19894'])
diff --git a/testsuite/tests/rts/linker/all.T b/testsuite/tests/rts/linker/all.T
index 32827de494..728a592b4e 100644
--- a/testsuite/tests/rts/linker/all.T
+++ b/testsuite/tests/rts/linker/all.T
@@ -82,11 +82,14 @@ test('T5435_dyn_gcc', extra_files(['T5435.hs', 'T5435_gcc.c']) , makefile_test,
 
 ######################################
 test('linker_unload',
-     [extra_files(['LinkerUnload.hs', 'Test.hs']), req_rts_linker],
+     [extra_files(['LinkerUnload.hs', 'Test.hs']),
+      req_rts_linker],
      makefile_test, ['linker_unload'])
 
 test('linker_unload_native',
-     [extra_files(['LinkerUnload.hs', 'Test.hs']), req_rts_linker,
+     [extra_files(['LinkerUnload.hs', 'Test.hs']),
+      req_rts_linker,
+      unless(have_dynamic(), skip),
       when(opsys('darwin') or opsys('mingw32'), skip)],
      makefile_test, ['linker_unload_native'])
 
diff --git a/testsuite/tests/safeHaskell/check/pkg01/all.T b/testsuite/tests/safeHaskell/check/pkg01/all.T
index 511c458815..fd23b2d362 100644
--- a/testsuite/tests/safeHaskell/check/pkg01/all.T
+++ b/testsuite/tests/safeHaskell/check/pkg01/all.T
@@ -17,7 +17,7 @@ if config.have_profiling:
 else:
     prof = '--disable-library-profiling'
 
-if config.have_shared_libs:
+if config.have_dynamic:
     dyn = '--enable-shared'
 else:
     dyn = '--disable-shared'