hadrian: Ensure that settings is regenerated during bindist installationwip/T20253

Previously Hadrian would simply install the settings file generated in
the build environment during the binary distribution installation. This
is wrong since these environments may differ (e.g. different `cc`
versions).

We noticed on Darwin when installation of a binary distribution produced
on a newer Darwin release resulted in a broken compiler due to the
installed `settings` file incorrectly claiming that `cc` supported
`-no-pie`.

Fixing this sadly requires a bit of code duplication since `settings` is
produced by Hadrian and not `configure`. For now I have simply
duplicated the `settings` generation logic used by the Make build system
into Hadrian's bindist Makefile.

Ultimately the solution will probably involve shipping a freestanding
utility to replace `configure`'s toolchain probing logic and generate a
toolchain description file (similar to `settings`) as described
in #19877.

Fixes #20253.

3 files changed, 65 insertions, 1 deletions

diff --git a/hadrian/bindist/Makefile b/hadrian/bindist/Makefile
index 892bbb4f64..40ccaafe31 100644
--- a/hadrian/bindist/Makefile
+++ b/hadrian/bindist/Makefile
@@ -95,6 +95,62 @@ ActualLibsDir=${ghclibdir}/lib
 endif
 WrapperBinsDir=${bindir}
 
+# N.B. this is duplicated from includes/ghc.mk.
+lib/settings :
+	$(call removeFiles,$@)
+	@echo '[("GCC extra via C opts", "$(GccExtraViaCOpts)")' >> $@
+	@echo ',("C compiler command", "$(SettingsCCompilerCommand)")' >> $@
+	@echo ',("C compiler flags", "$(SettingsCCompilerFlags)")' >> $@
+	@echo ',("C++ compiler flags", "$(SettingsCxxCompilerFlags)")' >> $@
+	@echo ',("C compiler link flags", "$(SettingsCCompilerLinkFlags)")' >> $@
+	@echo ',("C compiler supports -no-pie", "$(SettingsCCompilerSupportsNoPie)")' >> $@
+	@echo ',("Haskell CPP command", "$(SettingsHaskellCPPCommand)")' >> $@
+	@echo ',("Haskell CPP flags", "$(SettingsHaskellCPPFlags)")' >> $@
+	@echo ',("ld command", "$(SettingsLdCommand)")' >> $@
+	@echo ',("ld flags", "$(SettingsLdFlags)")' >> $@
+	@echo ',("ld supports compact unwind", "$(LdHasNoCompactUnwind)")' >> $@
+	@echo ',("ld supports build-id", "$(LdHasBuildId)")' >> $@
+	@echo ',("ld supports filelist", "$(LdHasFilelist)")' >> $@
+	@echo ',("ld is GNU ld", "$(LdIsGNULd)")' >> $@
+	@echo ',("Merge objects command", "$(SettingsMergeObjectsCommand)")' >> $@
+	@echo ',("Merge objects flags", "$(SettingsMergeObjectsFlags)")' >> $@
+	@echo ',("ar command", "$(SettingsArCommand)")' >> $@
+	@echo ',("ar flags", "$(ArArgs)")' >> $@
+	@echo ',("ar supports at file", "$(ArSupportsAtFile)")' >> $@
+	@echo ',("ranlib command", "$(SettingsRanlibCommand)")' >> $@
+	@echo ',("otool command", "$(SettingsOtoolCommand)")' >> $@
+	@echo ',("install_name_tool command", "$(SettingsInstallNameToolCommand)")' >> $@
+	@echo ',("touch command", "$(SettingsTouchCommand)")' >> $@
+	@echo ',("dllwrap command", "$(SettingsDllWrapCommand)")' >> $@
+	@echo ',("windres command", "$(SettingsWindresCommand)")' >> $@
+	@echo ',("libtool command", "$(SettingsLibtoolCommand)")' >> $@
+	@echo ',("unlit command", "$$topdir/bin/unlit")' >> $@
+	@echo ',("cross compiling", "$(CrossCompiling)")' >> $@
+	@echo ',("target platform string", "$(TARGETPLATFORM)")' >> $@
+	@echo ',("target os", "$(HaskellTargetOs)")' >> $@
+	@echo ',("target arch", "$(HaskellTargetArch)")' >> $@
+	@echo ',("target word size", "$(TargetWordSize)")' >> $@
+	@echo ',("target word big endian", "$(TargetWordBigEndian)")' >> $@
+	@echo ',("target has GNU nonexec stack", "$(TargetHasGnuNonexecStack)")' >> $@
+	@echo ',("target has .ident directive", "$(TargetHasIdentDirective)")' >> $@
+	@echo ',("target has subsections via symbols", "$(TargetHasSubsectionsViaSymbols)")' >> $@
+	@echo ',("target has RTS linker", "$(TargetHasRTSLinker)")' >> $@
+	@echo ',("Unregisterised", "$(GhcUnregisterised)")' >> $@
+	@echo ',("LLVM target", "$(LLVMTarget_CPP)")' >> $@
+	@echo ',("LLVM llc command", "$(SettingsLlcCommand)")' >> $@
+	@echo ',("LLVM opt command", "$(SettingsOptCommand)")' >> $@
+	@echo ',("LLVM clang command", "$(SettingsClangCommand)")' >> $@
+	@echo
+	@echo ',("bignum backend", "$(BIGNUM_BACKEND)")' >> $@
+	@echo ',("Use interpreter", "$(GhcWithInterpreter)")' >> $@
+	@echo ',("Support SMP", "$(GhcWithSMP)")' >> $@
+	@echo ',("RTS ways", "$(GhcRTSWays)")' >> $@
+	@echo ',("Tables next to code", "$(TablesNextToCode)")' >> $@
+	@echo ',("Leading underscore", "$(LeadingUnderscore)")' >> $@
+	@echo ',("Use LibFFI", "$(UseLibffiForAdjustors)")' >> $@
+	@echo ",(\"RTS expects libdw\", \"$(GhcRtsWithLibdw)\")" >> $@
+	@echo "]" >> $@
+
 # We need to install binaries relative to libraries.
 BINARIES = $(wildcard ./bin/*)
 install_bin_libdir:
@@ -110,7 +166,7 @@ install_bin_direct:
 	cp ./bin/* "$(WrapperBinsDir)/"
 
 LIBRARIES = $(wildcard ./lib/*)
-install_lib:
+install_lib: lib/settings
 	@echo "Copying libraries to $(ActualLibsDir)"
 	$(INSTALL_DIR) "$(ActualLibsDir)"
 	for i in $(LIBRARIES); do \
diff --git a/hadrian/src/Rules/BinaryDist.hs b/hadrian/src/Rules/BinaryDist.hs
index 6c6535fcc3..5637915ebb 100644
--- a/hadrian/src/Rules/BinaryDist.hs
+++ b/hadrian/src/Rules/BinaryDist.hs
@@ -171,6 +171,13 @@ bindistRules = do
         copyDirectory (ghcBuildDir -/- "lib") bindistFilesDir
         copyDirectory (rtsIncludeDir)         bindistFilesDir
 
+        -- The settings file must be regenerated by the bindist installation
+        -- logic to account for the environment discovered by the bindist
+        -- configure script on the host. Not on Windows, however, where
+        -- we do not ship a configure script with the bindist. See #20254.
+        unless windowsHost $
+            removeFile (bindistFilesDir -/- "lib" -/- "settings")
+
         -- Call ghc-pkg recache, after copying so the package.cache is
         -- accurate, then it's on the distributor to use `cp -a` to install
         -- a relocatable bindist.
diff --git a/rts/include/ghc.mk b/rts/include/ghc.mk
index 88cb12caff..26275075bd 100644
--- a/rts/include/ghc.mk
+++ b/rts/include/ghc.mk
@@ -207,6 +207,7 @@ $(eval $(call includesHeaderPlatform,1))
 
 includes_SETTINGS = rts/include/dist/build/settings
 
+# N.B. this is duplicated in hadrian/bindist/Makefile.
 $(includes_SETTINGS) : rts/include/Makefile | $$(dir $$@)/.
 	$(call removeFiles,$@)
 	@echo '[("GCC extra via C opts", "$(GccExtraViaCOpts)")' >> $@