Move "target has RTS linker" out of settings

We move the "target has RTS linker" information out of configure into a
predicate in GHC, and remove this option from the settings file where it
is unnecessary -- it's information statically known from the platform.

Note that previously we would consider `powerpc`s and `s390x`s other
than `powerpc-ibm-aix*` and `s390x-ibm-linux` to have an RTS linker,
but the RTS linker supports neither platform.

Closes #23361

6 files changed, 4 insertions, 7 deletions

diff --git a/hadrian/bindist/Makefile b/hadrian/bindist/Makefile
index 3f18720253..37e7504969 100644
--- a/hadrian/bindist/Makefile
+++ b/hadrian/bindist/Makefile
@@ -116,7 +116,6 @@ lib/settings : config.mk
 	@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)")' >> $@
 	@echo ',("target has libm", "$(TargetHasLibm)")' >> $@
 	@echo ',("Unregisterised", "$(GhcUnregisterised)")' >> $@
 	@echo ',("LLVM target", "$(LLVMTarget_CPP)")' >> $@
diff --git a/hadrian/bindist/config.mk.in b/hadrian/bindist/config.mk.in
index a134a00bd7..c98e25e58e 100644
--- a/hadrian/bindist/config.mk.in
+++ b/hadrian/bindist/config.mk.in
@@ -253,7 +253,6 @@ TargetWordBigEndian = @TargetWordBigEndian@
 TargetHasGnuNonexecStack = @TargetHasGnuNonexecStack@
 TargetHasIdentDirective = @TargetHasIdentDirective@
 TargetHasSubsectionsViaSymbols = @TargetHasSubsectionsViaSymbols@
-TargetHasRTSLinker = @TargetHasRTSLinker@
 TargetHasLibm = @TargetHasLibm@
 TablesNextToCode = @TablesNextToCode@
 
diff --git a/hadrian/cfg/system.config.in b/hadrian/cfg/system.config.in
index 57c57aa057..17465d2fb4 100644
--- a/hadrian/cfg/system.config.in
+++ b/hadrian/cfg/system.config.in
@@ -173,7 +173,6 @@ target-word-big-endian = @TargetWordBigEndian@
 target-has-gnu-nonexec-stack = @TargetHasGnuNonexecStack@
 target-has-ident-directive = @TargetHasIdentDirective@
 target-has-subsections-via-symbols = @TargetHasSubsectionsViaSymbols@
-target-has-rts-linker = @TargetHasRTSLinker@
 target-has-libm = @TargetHasLibm@
 target-arm-version    = @ARM_ISA@
 
diff --git a/hadrian/src/Oracles/Setting.hs b/hadrian/src/Oracles/Setting.hs
index bf49bd1fe0..0ff3174673 100644
--- a/hadrian/src/Oracles/Setting.hs
+++ b/hadrian/src/Oracles/Setting.hs
@@ -79,7 +79,6 @@ data Setting = BuildArch
              | TargetOsHaskell
              | TargetArmVersion
              | TargetWordSize
-             | TargetHasRtsLinker
              | BourneShell
 
 -- TODO: Reduce the variety of similar flags (e.g. CPP and non-CPP versions).
@@ -181,7 +180,6 @@ setting key = lookupSystemConfig $ case key of
     TargetArchHaskell  -> "target-arch-haskell"
     TargetOsHaskell    -> "target-os-haskell"
     TargetWordSize     -> "target-word-size"
-    TargetHasRtsLinker -> "target-has-rts-linker"
     BourneShell        -> "bourne-shell"
 
 bootIsStage0 :: Stage -> Stage
diff --git a/hadrian/src/Rules/Generate.hs b/hadrian/src/Rules/Generate.hs
index 6aa9f19b47..32a35e9048 100644
--- a/hadrian/src/Rules/Generate.hs
+++ b/hadrian/src/Rules/Generate.hs
@@ -448,7 +448,6 @@ generateSettings = do
         , ("target has GNU nonexec stack", expr $ lookupSystemConfig "target-has-gnu-nonexec-stack")
         , ("target has .ident directive", expr $ lookupSystemConfig "target-has-ident-directive")
         , ("target has subsections via symbols", expr $ lookupSystemConfig "target-has-subsections-via-symbols")
-        , ("target has RTS linker", expr $ lookupSystemConfig "target-has-rts-linker")
         , ("target has libm", expr $  lookupSystemConfig "target-has-libm")
         , ("Unregisterised", expr $ yesNo <$> flag GhcUnregisterised)
         , ("LLVM target", getSetting LlvmTarget)
diff --git a/hadrian/src/Settings/Builders/RunTest.hs b/hadrian/src/Settings/Builders/RunTest.hs
index 5e1e16d5aa..b526294f40 100644
--- a/hadrian/src/Settings/Builders/RunTest.hs
+++ b/hadrian/src/Settings/Builders/RunTest.hs
@@ -134,7 +134,10 @@ inTreeCompilerArgs stg = do
     libdir           <- System.FilePath.normalise . (top -/-)
                     <$> stageLibPath stg
 
-    rtsLinker <- (== "YES") <$> setting TargetHasRtsLinker
+    -- For this information, we need to query ghc --info, however, that would
+    -- require building ghc, which we don't want to do here. Therefore, the
+    -- logic from `platformHasRTSLinker` is duplicated here.
+    let rtsLinker = not $ arch `elem` ["powerpc", "powerpc64", "powerpc64le", "s390x", "riscv64", "loongarch64", "javascript", "wasm32"]
 
     return TestCompilerArgs{..}