Specify constant context in constant emitter
The constant emitter may need to evaluate the expression in a constant context.
For exasmple, global initializer lists.
llvm-svn: 348070
diff --git a/clang/test/CodeGen/builtin-constant-p.c b/clang/test/CodeGen/builtin-constant-p.c
new file mode 100644
index 0000000..7f4e7d0
--- /dev/null
+++ b/clang/test/CodeGen/builtin-constant-p.c
@@ -0,0 +1,168 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s -O2 | FileCheck %s
+
+int a = 42;
+
+inline int bcp(int x) {
+ return __builtin_constant_p(x);
+}
+
+/* --- Compound literals */
+
+struct foo { int x, y; };
+
+int y;
+struct foo f = (struct foo){ __builtin_constant_p(y), 42 };
+
+struct foo test0(int expr) {
+ // CHECK: define i64 @test0(i32 %expr)
+ // CHECK: call i1 @llvm.is.constant.i32(i32 %expr)
+ struct foo f = (struct foo){ __builtin_constant_p(expr), 42 };
+ return f;
+}
+
+/* --- Pointer types */
+
+inline int test1_i(int *x) {
+ return *x;
+}
+
+int test1() {
+ // CHECK: define i32 @test1
+ // CHECK: add nsw i32 %0, -13
+ // CHECK-NEXT: call i1 @llvm.is.constant.i32(i32 %sub)
+ return bcp(test1_i(&a) - 13);
+}
+
+int test2() {
+ // CHECK: define i32 @test2
+ // CHECK: ret i32 0
+ return __builtin_constant_p(&a - 13);
+}
+
+inline int test3_i(int *x) {
+ return 42;
+}
+
+int test3() {
+ // CHECK: define i32 @test3
+ // CHECK: ret i32 1
+ return bcp(test3_i(&a) - 13);
+}
+
+/* --- Aggregate types */
+
+int b[] = {1, 2, 3};
+
+int test4() {
+ // CHECK: define i32 @test4
+ // CHECK: ret i32 0
+ return __builtin_constant_p(b);
+}
+
+const char test5_c[] = {1, 2, 3, 0};
+
+int test5() {
+ // CHECK: define i32 @test5
+ // CHECK: ret i32 0
+ return __builtin_constant_p(test5_c);
+}
+
+inline char test6_i(const char *x) {
+ return x[1];
+}
+
+int test6() {
+ // CHECK: define i32 @test6
+ // CHECK: ret i32 0
+ return __builtin_constant_p(test6_i(test5_c));
+}
+
+/* --- Non-constant global variables */
+
+int test7() {
+ // CHECK: define i32 @test7
+ // CHECK: call i1 @llvm.is.constant.i32(i32 %0)
+ return bcp(a);
+}
+
+/* --- Constant global variables */
+
+const int c = 42;
+
+int test8() {
+ // CHECK: define i32 @test8
+ // CHECK: ret i32 1
+ return bcp(c);
+}
+
+/* --- Array types */
+
+int arr[] = { 1, 2, 3 };
+const int c_arr[] = { 1, 2, 3 };
+
+int test9() {
+ // CHECK: define i32 @test9
+ // CHECK: call i1 @llvm.is.constant.i32(i32 %0)
+ return __builtin_constant_p(arr[2]);
+}
+
+int test10() {
+ // CHECK: define i32 @test10
+ // CHECK: ret i32 1
+ return __builtin_constant_p(c_arr[2]);
+}
+
+int test11() {
+ // CHECK: define i32 @test11
+ // CHECK: ret i32 0
+ return __builtin_constant_p(c_arr);
+}
+
+/* --- Function pointers */
+
+int test12() {
+ // CHECK: define i32 @test12
+ // CHECK: ret i32 0
+ return __builtin_constant_p(&test10);
+}
+
+int test13() {
+ // CHECK: define i32 @test13
+ // CHECK: ret i32 1
+ return __builtin_constant_p(&test10 != 0);
+}
+
+typedef unsigned long uintptr_t;
+#define assign(p, v) ({ \
+ uintptr_t _r_a_p__v = (uintptr_t)(v); \
+ if (__builtin_constant_p(v) && _r_a_p__v == (uintptr_t)0) { \
+ union { \
+ uintptr_t __val; \
+ char __c[1]; \
+ } __u = { \
+ .__val = (uintptr_t)_r_a_p__v \
+ }; \
+ *(volatile unsigned int*)&p = *(unsigned int*)(__u.__c); \
+ __u.__val; \
+ } \
+ _r_a_p__v; \
+})
+
+typedef void fn_p(void);
+extern fn_p *dest_p;
+
+static void src_fn(void) {
+}
+
+void test14() {
+ assign(dest_p, src_fn);
+}
+
+extern int test15_v;
+
+struct { const char *t; int a; } test15[] = {
+ { "tag", __builtin_constant_p(test15_v) && !test15_v ? 1 : 0 }
+};
+
+extern char test16_v;
+struct { int a; } test16 = { __builtin_constant_p(test16_v) };