carwil updated this revision to Diff 185277.
carwil added a comment.
Removed the complicated frame pointer/ffixed combination errors in favour of an
always on warning (in a new group, so it can be silenced).
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D56003/new/
https://reviews.llvm.org/D56003
Files:
docs/ClangCommandLineReference.rst
include/clang/Basic/DiagnosticDriverKinds.td
include/clang/Basic/DiagnosticGroups.td
include/clang/Driver/Options.td
lib/Basic/Targets/ARM.cpp
lib/Basic/Targets/ARM.h
lib/Driver/ToolChains/Arch/ARM.cpp
test/Driver/arm-reserved-reg-options.c
test/Sema/arm-global-regs.c
Index: test/Sema/arm-global-regs.c
===================================================================
--- /dev/null
+++ test/Sema/arm-global-regs.c
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -ffreestanding -fsyntax-only -verify -triple arm %s
+
+// Check a small subset of valid and invalid global register variable declarations.
+
+register unsigned arm_r3 __asm("r3"); //expected-error {{register 'r3' unsuitable for global register variables on this target}}
+
+register unsigned arm_r12 __asm("r12"); //expected-error {{register 'r12' unsuitable for global register variables on this target}}
+
+register unsigned arm_r5 __asm("r5");
+
+register unsigned arm_r9 __asm("r9");
+
+register unsigned arm_sp __asm("sp");
\ No newline at end of file
Index: test/Driver/arm-reserved-reg-options.c
===================================================================
--- /dev/null
+++ test/Driver/arm-reserved-reg-options.c
@@ -0,0 +1,35 @@
+// ## FP ARM + Thumb
+// RUN: %clang -target arm-arm-none-eabi -### -ffixed-r11 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R11 %s
+// RUN: %clang -target arm-arm-none-eabi -### -ffixed-r11 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// RUN: %clang -target arm-arm-none-eabi -### -ffixed-r7 -mthumb -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R7 %s
+// RUN: %clang -target arm-arm-none-eabi -### -ffixed-r7 -mthumb -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// RUN: %clang -target thumbv6m-none-eabi -### -ffixed-r7 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R7 %s
+// RUN: %clang -target thumbv6m-none-eabi -### -ffixed-r7 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// ## FP Darwin (R7)
+// RUN: %clang -target armv6-apple-darwin9 -### -ffixed-r7 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R7 %s
+// RUN: %clang -target armv6-apple-darwin9 -### -ffixed-r7 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// RUN: %clang -target armv6-apple-ios3 -### -ffixed-r7 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R7 %s
+// RUN: %clang -target armv6-apple-ios3 -### -ffixed-r7 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// RUN: %clang -target armv7s-apple-darwin10 -### -ffixed-r7 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R7 %s
+// RUN: %clang -target armv7s-apple-darwin10 -### -ffixed-r7 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// ## FP Windows (R11)
+// RUN: %clang -target armv7-windows -### -ffixed-r11 -c %s 2>&1 | FileCheck -check-prefix=CHECK-WARNING-R11 %s
+// RUN: %clang -target armv7-windows -### -ffixed-r11 -Wno-fixed-registers -c %s 2>&1 | FileCheck -check-prefix=CHECK-NO-WARNING %s
+
+// ## FRWPI (R9)
+// RUN: %clang -target arm-arm-none-eabi -### -frwpi -ffixed-r9 -c %s 2>&1 | FileCheck -check-prefix=CHECK-RESERVED-FRWPI-CONFLICT %s
+// RUN: %clang -target arm-arm-none-eabi -### -ffixed-r9 -c %s 2>&1 | FileCheck -check-prefix=CHECK-RESERVED-FRWPI-VALID %s
+// RUN: %clang -target arm-arm-none-eabi -### -frwpi -c %s 2>&1 | FileCheck -check-prefix=CHECK-RESERVED-FRWPI-VALID %s
+
+// CHECK-WARNING-R11: warning: '-ffixed-r11' has been specified but 'r11' may still be used as a frame pointer [-Wfixed-registers]
+// CHECK-WARNING-R7: warning: '-ffixed-r7' has been specified but 'r7' may still be used as a frame pointer [-Wfixed-registers]
+// CHECK-NO-WARNING-NOT: may still be used as a frame pointer [-Wfixed-registers]
+
+// CHECK-RESERVED-FRWPI-CONFLICT: option '-ffixed-r9' cannot be specified with '-frwpi'
+// CHECK-RESERVED-FRWPI-VALID-NOT: option '-ffixed-r9' cannot be specified with '-frwpi'
\ No newline at end of file
Index: lib/Driver/ToolChains/Arch/ARM.cpp
===================================================================
--- lib/Driver/ToolChains/Arch/ARM.cpp
+++ lib/Driver/ToolChains/Arch/ARM.cpp
@@ -547,11 +547,37 @@
Features.push_back("+strict-align");
}
- // llvm does not support reserving registers in general. There is support
- // for reserving r9 on ARM though (defined as a platform-specific register
- // in ARM EABI).
- if (Args.hasArg(options::OPT_ffixed_r9))
- Features.push_back("+reserve-r9");
+ // Do not allow r9 reservation with -frwpi.
+ if (Args.hasArg(options::OPT_ffixed_r9) && Args.hasArg(options::OPT_frwpi)) {
+ Arg *A = Args.getLastArg(options::OPT_ffixed_r9);
+ Arg *B = Args.getLastArg(options::OPT_frwpi);
+ D.Diag(diag::err_opt_not_valid_with_opt) << A->getAsString(Args) << B->getAsString(Args);
+ }
+
+ // The compiler can still use a FP in certain circumstances,
+ // even when frame pointer elimination is enabled. Thus we should
+ // give a warning when trying to reserve a target's FP register.
+ const llvm::opt::OptSpecifier RestrictFPOpt =
+ (Triple.isOSDarwin() || (!Triple.isOSWindows() && Triple.isThumb()))
+ ? options::OPT_ffixed_r7
+ : options::OPT_ffixed_r11;
+ if (Args.hasArg(RestrictFPOpt)) {
+ const std::string OptStr = Args.getLastArg(RestrictFPOpt)->getAsString(Args);
+ const unsigned int SubStrIndex = strlen("ffixed-r");
+ D.Diag(diag::warn_reserved_frame_pointer) << OptStr << OptStr.substr(SubStrIndex);
+ }
+
+// Reservation of general purpose registers.
+#define HANDLE_FFIXED_R(n) \
+ if (Args.hasArg(options::OPT_ffixed_r##n)) \
+ Features.push_back("+reserve-r" #n)
+ HANDLE_FFIXED_R(5);
+ HANDLE_FFIXED_R(6);
+ HANDLE_FFIXED_R(7);
+ HANDLE_FFIXED_R(8);
+ HANDLE_FFIXED_R(9);
+ HANDLE_FFIXED_R(10);
+ HANDLE_FFIXED_R(11);
// The kext linker doesn't know how to deal with movw/movt.
if (KernelOrKext || Args.hasArg(options::OPT_mno_movt))
Index: lib/Basic/Targets/ARM.h
===================================================================
--- lib/Basic/Targets/ARM.h
+++ lib/Basic/Targets/ARM.h
@@ -147,6 +147,9 @@
ArrayRef<const char *> getGCCRegNames() const override;
ArrayRef<TargetInfo::GCCRegAlias> getGCCRegAliases() const override;
+ bool validateGlobalRegisterVariable(StringRef RegName,
+ unsigned RegSize,
+ bool &HasSizeMismatch) const override;
bool validateAsmConstraint(const char *&Name,
TargetInfo::ConstraintInfo &Info) const override;
std::string convertConstraint(const char *&Constraint) const override;
Index: lib/Basic/Targets/ARM.cpp
===================================================================
--- lib/Basic/Targets/ARM.cpp
+++ lib/Basic/Targets/ARM.cpp
@@ -823,6 +823,22 @@
return llvm::makeArrayRef(GCCRegAliases);
}
+bool ARMTargetInfo::validateGlobalRegisterVariable(
+ StringRef RegName, unsigned RegSize, bool &HasSizeMismatch) const {
+ if (RegName.equals("r5") ||
+ RegName.equals("r6") ||
+ RegName.equals("r7") ||
+ RegName.equals("r8") ||
+ RegName.equals("r9") ||
+ RegName.equals("r10") ||
+ RegName.equals("r11") ||
+ RegName.equals("sp")) {
+ HasSizeMismatch = false;
+ return true;
+ }
+ return false;
+}
+
bool ARMTargetInfo::validateAsmConstraint(
const char *&Name, TargetInfo::ConstraintInfo &Info) const {
switch (*Name) {
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -2115,8 +2115,9 @@
def mno_restrict_it: Flag<["-"], "mno-restrict-it">, Group<m_arm_Features_Group>,
HelpText<"Allow generation of deprecated IT blocks for ARMv8. It is off by default for ARMv8 Thumb mode">;
def marm : Flag<["-"], "marm">, Alias<mno_thumb>;
-def ffixed_r9 : Flag<["-"], "ffixed-r9">, Group<m_arm_Features_Group>,
- HelpText<"Reserve the r9 register (ARM only)">;
+foreach i = {5-11} in
+ def ffixed_r#i : Flag<["-"], "ffixed-r"#i>, Group<m_arm_Features_Group>,
+ HelpText<"Reserve the r"#i#" register (ARM only)">;
def mno_movt : Flag<["-"], "mno-movt">, Group<m_arm_Features_Group>,
HelpText<"Disallow use of movt/movw pairs (ARM only)">;
def mcrc : Flag<["-"], "mcrc">, Group<m_Group>,
Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -1052,3 +1052,6 @@
def CrossTU : DiagGroup<"ctu">;
def CTADMaybeUnsupported : DiagGroup<"ctad-maybe-unsupported">;
+
+// Register reservation.
+def FixedRegs : DiagGroup<"fixed-registers">;
\ No newline at end of file
Index: include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- include/clang/Basic/DiagnosticDriverKinds.td
+++ include/clang/Basic/DiagnosticDriverKinds.td
@@ -424,4 +424,9 @@
"specify a MSP430 device, or -mhwmult to set hardware multiply type "
"explicitly.">, InGroup<InvalidCommandLineArgument>;
+// Frame pointer reservation.
+def warn_reserved_frame_pointer : Warning<
+ "'%0' has been specified but '%1' may still be used as a frame pointer">,
+ InGroup<FixedRegs>;
+
}
Index: docs/ClangCommandLineReference.rst
===================================================================
--- docs/ClangCommandLineReference.rst
+++ docs/ClangCommandLineReference.rst
@@ -2402,10 +2402,34 @@
ARM
---
+.. option:: -ffixed-r5
+
+Reserve the r5 register (ARM only)
+
+.. option:: -ffixed-r6
+
+Reserve the r6 register (ARM only)
+
+.. option:: -ffixed-r7
+
+Reserve the r7 register (ARM only)
+
+.. option:: -ffixed-r8
+
+Reserve the r8 register (ARM only)
+
.. option:: -ffixed-r9
Reserve the r9 register (ARM only)
+.. option:: -ffixed-r10
+
+Reserve the r10 register (ARM only)
+
+.. option:: -ffixed-r11
+
+Reserve the r11 register (ARM only)
+
.. option:: -mexecute-only, -mno-execute-only, -mpure-code
Disallow generation of data access to code sections (ARM only)
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