[PATCH] D150902: [ARM][Driver] Warn if -mhard-float is incompatible

[Michael Platings via Phabricator via cfe-commits]

michaelplatings updated this revision to Diff 524302.
michaelplatings added a comment.

Tweak tests to use -### to run faster.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D150902/new/

https://reviews.llvm.org/D150902

Files:
  clang/include/clang/Basic/DiagnosticDriverKinds.td
  clang/lib/Driver/ToolChains/Arch/ARM.cpp
  clang/test/Driver/arm-no-float-regs.c


Index: clang/test/Driver/arm-no-float-regs.c
===================================================================
--- /dev/null
+++ clang/test/Driver/arm-no-float-regs.c
@@ -0,0 +1,23 @@
+// REQUIRES: arm-registered-target
+
+// Check that -mfloat-abi=hard gives a warning if FP registers aren't available.
+// RUN: %clang --target=arm-none-eabi -mcpu=cortex-m0 -mfloat-abi=hard -### -c %s 2>&1
+
+// RUN: %clang --target=arm-none-eabi -mcpu=cortex-m0 -mhard-float -### -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=HARDFLOAT %s
+
+// -mfloat-abi=hard and -march=...+nofp are incompatible in this instance:
+// RUN: %clang --target=arm-none-eabi -march=armv8.1-m.main+nofp -mfloat-abi=hard -### -c %s 2>&1
+// -mfloat-abi=hard and -march=...+nofp are compatible in this instance:
+// RUN: %clang --target=arm-none-eabi -march=armv8.1-m.main+mve+nofp -mfloat-abi=hard -### -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=NOWARN %s
+
+// Here the float ABI is calculated as "hard" and FP registers are
+// calculated to not be available. Since the float ABI wasn't specified
+// explicitly, the warning should not be emitted.
+// RUN: %clang -target thumbv5-windows -mcpu=arm10tdmi -### -c %s -o /dev/null 2>&1 \
+// RUN:   | FileCheck -check-prefix=NOWARN %s
+
+// CHECK: warning: '-mfloat-abi=hard': selected processor lacks floating point registers
+// HARDFLOAT: warning: '-mhard-float': selected processor lacks floating point registers
+// NOWARN-NOT: selected processor lacks floating point registers
Index: clang/lib/Driver/ToolChains/Arch/ARM.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -144,6 +144,22 @@
         << A->getSpelling() << A->getValue();
 }
 
+// If -mfloat-abi=hard or -mhard-float are specified explicitly then check that
+// floating point registers are available on the target CPU.
+static void checkARMFloatABI(const Driver &D, const ArgList &Args,
+                             const std::vector<StringRef> &Features) {
+  if (llvm::find(Features, "-fpregs") == Features.end())
+    return;
+  const Arg *A =
+      Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
+                      options::OPT_mfloat_abi_EQ);
+  if (A && (A->getOption().matches(options::OPT_mhard_float) ||
+            (A->getOption().matches(options::OPT_mfloat_abi_EQ) &&
+             A->getValue() == StringRef("hard"))))
+    D.Diag(clang::diag::warn_drv_no_floating_point_registers)
+        << A->getAsString(Args);
+}
+
 bool arm::useAAPCSForMachO(const llvm::Triple &T) {
   // The backend is hardwired to assume AAPCS for M-class processors, ensure
   // the frontend matches that.
@@ -910,6 +926,8 @@
 
   if (Args.getLastArg(options::OPT_mno_bti_at_return_twice))
     Features.push_back("+no-bti-at-return-twice");
+
+  checkARMFloatABI(D, Args, Features);
 }
 
 std::string arm::getARMArch(StringRef Arch, const llvm::Triple &Triple) {
Index: clang/include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -417,6 +417,8 @@
 def warn_drv_unsupported_float_abi_by_lib : Warning<
   "float ABI '%0' is not supported by current library">,
   InGroup<DiagGroup<"unsupported-abi">>;
+def warn_drv_no_floating_point_registers: Warning<
+  "'%0': selected processor lacks floating point registers">;
 def warn_ignoring_ftabstop_value : Warning<
   "ignoring invalid -ftabstop value '%0', using default value %1">;
 def warn_drv_overriding_flag_option : Warning<


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