[PATCH] D108624: [Clang][RISCV] Implement getConstraintRegister for RISC-V

[Luís Marques via Phabricator via cfe-commits]

luismarques created this revision.
luismarques added reviewers: asb, thopre.
Herald added subscribers: vkmr, frasercrmck, evandro, apazos, sameer.abuasal, s.egerton, Jim, benna, psnobl, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217, kito-cheng, niosHD, sabuasal, simoncook, johnrusso, rbar.
luismarques requested review of this revision.
Herald added subscribers: cfe-commits, MaskRay.
Herald added a project: clang.

The getConstraintRegister method is used by semantic checking of inline assembly statements in order to diagnose conflicts between clobber list and input/output lists. By overriding getConstraintRegister we get those diagnostics and we match RISC-V GCC's behavior. The implementation is trivial due to the lack of single-register RISC-V-specific constraints.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D108624

Files:
  clang/lib/Basic/Targets/RISCV.h
  clang/test/Sema/inline-asm-validate-riscv.c


Index: clang/test/Sema/inline-asm-validate-riscv.c
===================================================================
--- clang/test/Sema/inline-asm-validate-riscv.c
+++ clang/test/Sema/inline-asm-validate-riscv.c
@@ -21,3 +21,11 @@
   asm volatile ("" :: "K"(BelowMin)); // expected-error{{value '-1' out of range for constraint 'K'}}
   asm volatile ("" :: "K"(AboveMax)); // expected-error{{value '32' out of range for constraint 'K'}}
 }
+
+void test_clobber_conflict(void) {
+  register long x10 asm("x10");
+  asm volatile("nop" :: "r"(x10) : "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("nop" :: "r"(x10) : "a0"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("nop" : "=r"(x10) :: "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("nop" : "=r"(x10) :: "a0"); // expected-error {{conflicts with asm clobber list}}
+}
Index: clang/lib/Basic/Targets/RISCV.h
===================================================================
--- clang/lib/Basic/Targets/RISCV.h
+++ clang/lib/Basic/Targets/RISCV.h
@@ -82,6 +82,11 @@
 
   const char *getClobbers() const override { return ""; }
 
+  StringRef getConstraintRegister(StringRef Constraint,
+                                  StringRef Expression) const override {
+    return Expression;
+  }
+
   ArrayRef<const char *> getGCCRegNames() const override;
 
   int getEHDataRegisterNumber(unsigned RegNo) const override {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D108624.368322.patch
Type: text/x-patch
Size: 1457 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20210824/9df229f6/attachment-0001.bin>