[ARM][Driver] Change float-abi warning

Previously the warning stated "flag ignored" which is only partially true - the invalid flag would prevent -feature +soft-float-abi from being emitted which resulted in user-visible behaviour like __ARM_PCS_VFP being defined. Rather than attempt to coerce invalid flags into valid behaviour, don't describe the expected behaviour. Ideally the warning would be an error, as it is in GCC. However there are tests in llvm-project that trigger the warning. Therefore one has to assume that making the warning an error would break other code that already exists in the wild. Also apply test improvements suggested by @MaskRay on D150902. Reviewed By: simon_tatham Differential Revision: https://reviews.llvm.org/D154578
llvm · Jul 7, 2023 · 7916573 · 7916573
1 parent 336d728
commit 7916573
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Showing 3 changed files with 8 additions and 7 deletions.
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -416,10 +416,10 @@ def warn_drv_assuming_mfloat_abi_is : Warning<
   "unknown platform, assuming -mfloat-abi=%0">;
 def warn_drv_unsupported_float_abi_by_lib : Warning<
   "float ABI '%0' is not supported by current library">,
-  InGroup<DiagGroup<"unsupported-abi">>;
+  InGroup<UnsupportedABI>;
 def warn_drv_no_floating_point_registers: Warning<
-  "'%0': selected processor lacks floating point registers; flag ignored">,
-  InGroup<OptionIgnored>;
+  "'%0': selected processor lacks floating point registers">,
+  InGroup<UnsupportedABI>;
 def warn_ignoring_ftabstop_value : Warning<
   "ignoring invalid -ftabstop value '%0', using default value %1">;
 def warn_drv_overriding_flag_option : Warning<

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1349,6 +1349,8 @@ def OptionIgnored : DiagGroup<"option-ignored">;
 
 def UnknownArgument : DiagGroup<"unknown-argument">;
 
+def UnsupportedABI : DiagGroup<"unsupported-abi">;
+
 // A warning group for warnings about code that clang accepts when
 // compiling OpenCL C/C++ but which is not compatible with the SPIR(-V) spec.
 def SpirCompat : DiagGroup<"spir-compat">;

diff --git a/clang/test/Driver/arm-no-float-regs.c b/clang/test/Driver/arm-no-float-regs.c
@@ -1,7 +1,6 @@
-// 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 -mfloat-abi=hard -### -c %s 2>&1 \
+// RUN:   | FileCheck %s
 
 // RUN: %clang --target=arm-none-eabi -mcpu=cortex-m0 -mhard-float -### -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=HARDFLOAT %s
@@ -20,4 +19,4 @@
 
 // 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
+// NOWARN-NOT: warning: