This patch adds support for SYM_UNION in symbol_type(). The LLVM API does not
provide support for unions so we treat them as opaque structs.
Cc: Christopher Li <sparse@xxxxxxxxxxx>
Cc: Jeff Garzik <jgarzik@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
---
sparse-llvm.c | 20 ++++++++++++++++++++
validation/backend/union.c | 12 ++++++++++++
2 files changed, 32 insertions(+), 0 deletions(-)
create mode 100644 validation/backend/union.c
diff --git a/sparse-llvm.c b/sparse-llvm.c
index a678d9c..7f46c8a 100644
--- a/sparse-llvm.c
+++ b/sparse-llvm.c
@@ -80,6 +80,23 @@ static LLVMTypeRef sym_struct_type(LLVMModuleRef module, struct symbol *sym)
return ret;
}
+static LLVMTypeRef sym_union_type(LLVMModuleRef module, struct symbol *sym)
+{
+ LLVMTypeRef elements;
+ unsigned union_size;
+
+ /*
+ * There's no union support in the LLVM API so we treat unions as
+ * opaque structs. The downside is that we lose type information on the
+ * members but as LLVM doesn't care, neither do we.
+ */
+ union_size = sym->bit_size / 8;
+
+ elements = LLVMArrayType(LLVMInt8Type(), union_size);
+
+ return LLVMStructType(&elements, 1, 0 /* packed? */);
+}
+
static LLVMTypeRef sym_ptr_type(LLVMModuleRef module, struct symbol *sym)
{
LLVMTypeRef type = symbol_type(module, sym->ctype.base_type);
@@ -146,6 +163,9 @@ static LLVMTypeRef symbol_type(LLVMModuleRef module, struct symbol *sym)
case SYM_PTR:
ret = sym_ptr_type(module, sym);
break;
+ case SYM_UNION:
+ ret = sym_union_type(module, sym);
+ break;
case SYM_STRUCT:
ret = sym_struct_type(module, sym);
break;
diff --git a/validation/backend/union.c b/validation/backend/union.c
new file mode 100644
index 0000000..e155f6a
--- /dev/null
+++ b/validation/backend/union.c
@@ -0,0 +1,12 @@
+union foo {
+ unsigned long x;
+ unsigned char y;
+ char buf[128];
+};
+
+static union foo foo;
+
+/*
+ * check-name: Union code generation
+ * check-command: ./sparsec -c $file -o tmp.o
+ */
--
1.7.6.4
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