Author: glider
Date: Fri Aug 30 01:58:46 2019
New Revision: 370444
URL: http://llvm.org/viewvc/llvm-project?rev=370444&view=rev
Log:
[CodeGen]: fix error message for "=r" asm constraint
Summary:
Nico Weber reported that the following code:
char buf[9];
asm("" : "=r" (buf));
yields the "impossible constraint in asm: can't store struct into a register"
error message, although |buf| is not a struct (see
http://crbug.com/999160).
Make the error message more generic and add a test for it.
Also make sure other tests in x86_64-PR42672.c check for the full error
message.
Reviewers: eli.friedman, thakis
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66948
Modified:
cfe/trunk/lib/CodeGen/CGStmt.cpp
cfe/trunk/test/CodeGen/x86_64-PR42672.c
Modified: cfe/trunk/lib/CodeGen/CGStmt.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGStmt.cpp?rev=370444&r1=370443&r2=370444&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp Fri Aug 30 01:58:46 2019
@@ -2326,7 +2326,7 @@ void CodeGenFunction::EmitAsmStmt(const
const Expr *OutExpr = S.getOutputExpr(i);
CGM.Error(
OutExpr->getExprLoc(),
- "impossible constraint in asm: can't store struct into a
register");
+ "impossible constraint in asm: can't store value into a register");
return;
}
Dest = MakeAddrLValue(A, Ty);
Modified: cfe/trunk/test/CodeGen/x86_64-PR42672.c
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/x86_64-PR42672.c?rev=370444&r1=370443&r2=370444&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/x86_64-PR42672.c (original)
+++ cfe/trunk/test/CodeGen/x86_64-PR42672.c Fri Aug 30 01:58:46 2019
@@ -4,6 +4,7 @@
// RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_BIG
-emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_BIG
// RUN: %clang_cc1 -triple=x86_64-unknown-linux-gnu -DPOSSIBLE_X -emit-llvm %s
-o - 2>&1 | FileCheck %s --check-prefix=CHECK-X
// RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_X
-emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_X
+// RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_9BYTES
-emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_9BYTES
// Make sure Clang doesn't treat |lockval| as asm input.
void _raw_spin_lock(void) {
@@ -57,7 +58,7 @@ void odd_struct(void) {
: "=r"(str));
#endif
}
-// CHECK-IMPOSSIBLE_ODD: impossible constraint in asm
+// CHECK-IMPOSSIBLE_ODD: impossible constraint in asm: can't store value into
a register
// Check Clang reports an error if attempting to return a big structure via a
register.
void big_struct(void) {
@@ -69,7 +70,7 @@ void big_struct(void) {
: "=r"(str));
#endif
}
-// CHECK-IMPOSSIBLE_BIG: impossible constraint in asm
+// CHECK-IMPOSSIBLE_BIG: impossible constraint in asm: can't store value into
a register
// Clang is able to emit LLVM IR for an 16-byte structure.
void x_constraint_fit() {
@@ -100,3 +101,17 @@ void x_constraint_nofit() {
}
// CHECK-IMPOSSIBLE_X: invalid output size for constraint
+
+// http://crbug.com/999160
+// Clang used to report the following message:
+// "impossible constraint in asm: can't store struct into a register"
+// for the assembly directive below, although there's no struct.
+void crbug_999160_regtest() {
+#ifdef IMPOSSIBLE_9BYTES
+ char buf[9];
+ asm(""
+ : "=r"(buf));
+#endif
+}
+
+// CHECK-IMPOSSIBLE_9BYTES: impossible constraint in asm: can't store value
into a register
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