[clang] 34e055d - [Clang][RISCV] Implement getConstraintRegister for RISC-V

[Luís Marques via cfe-commits]

Author: Luís Marques
Date: 2021-08-26T17:43:43+01:00
New Revision: 34e055d33e37cd87b9f6f4b0431a4c061628d036

URL: https://github.com/llvm/llvm-project/commit/34e055d33e37cd87b9f6f4b0431a4c061628d036
DIFF: https://github.com/llvm/llvm-project/commit/34e055d33e37cd87b9f6f4b0431a4c061628d036.diff

LOG: [Clang][RISCV] Implement getConstraintRegister for RISC-V

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.

Differential Revision: https://reviews.llvm.org/D108624

Added: 
    

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

Removed: 
    


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diff  --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 7e0846581ca1f..9609b6fc3f307 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -82,6 +82,11 @@ class RISCVTargetInfo : public TargetInfo {
 
   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 {

diff  --git a/clang/test/Sema/inline-asm-validate-riscv.c b/clang/test/Sema/inline-asm-validate-riscv.c
index 744f73e23cf26..43a5378bc3f25 100644
--- a/clang/test/Sema/inline-asm-validate-riscv.c
+++ b/clang/test/Sema/inline-asm-validate-riscv.c
@@ -21,3 +21,11 @@ void K(int k) {
   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("" :: "r"(x10) : "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" :: "r"(x10) : "a0"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" : "=r"(x10) :: "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" : "=r"(x10) :: "a0"); // expected-error {{conflicts with asm clobber list}}
+}