Add test for PR24379

[john.brawn]

Summary

The fix for this is in LLVM but it depends on how clang handles the alias attribute, so add a test to the clang tests to make sure everything works together as expected.

[• rafael]

LGTM

test/CodeGen/alias.c

 // RUN: %clang_cc1 -triple i386-pc-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefix=CHECKBASIC %s
 // RUN: %clang_cc1 -triple armv7a-eabi -mfloat-abi hard -emit-llvm -o - %s | FileCheck -check-prefix=CHECKCC %s
+// RUN: %clang_cc1 -triple armv7a-eabi -mfloat-abi hard -S -o - %s | FileCheck -check-prefix=CHECKASM %s
 
 int g0;
-// CHECKBASIC: @g0 = common global i32 0
+// CHECKBASIC-DAG: @g0 = common global i32 0
+// CHECKASM-DAG: .comm g0,4,4
 __thread int TL_WITH_ALIAS;
 // CHECKBASIC-DAG: @TL_WITH_ALIAS = thread_local global i32 0, align 4
+// CHECKASM-DAG: .globl TL_WITH_ALIAS
+// CHECKASM-DAG: .size TL_WITH_ALIAS, 4
 static int bar1 = 42;
-// CHECKBASIC: @bar1 = internal global i32 42
+// CHECKBASIC-DAG: @bar1 = internal global i32 42
+// CHECKASM-DAG: bar1:
+// CHECKASM-DAG: .size bar1, 4
+
+// PR24379: alias variable expected to have same size as aliasee even when types differ
+const int wacom_usb_ids[] = {1, 1, 2, 3, 5, 8, 13, 0};
+// CHECKBASIC-DAG: @wacom_usb_ids = constant [8 x i32] [i32 1, i32 1, i32 2, i32 3, i32 5, i32 8, i32 13, i32 0], align 4
+// CHECKASM-DAG: .globl wacom_usb_ids
+// CHECKASM-DAG: .size wacom_usb_ids, 32
+extern const int __mod_usb_device_table __attribute__ ((alias("wacom_usb_ids")));
+// CHECKBASIC-DAG: @__mod_usb_device_table = alias getelementptr inbounds ([8 x i32], [8 x i32]* @wacom_usb_ids, i32 0, i32 0)
+// CHECKASM-DAG: .globl __mod_usb_device_table
+// CHECKASM-DAG: __mod_usb_device_table = wacom_usb_ids
+// CHECKASM-DAG-NOT: .size __mod_usb_device_table
 
 extern int g1;
 extern int g1 __attribute((alias("g0")));
 // CHECKBASIC-DAG: @g1 = alias i32* @g0
+// CHECKASM-DAG: .globl g1
+// CHECKASM-DAG: g1 = g0
+// CHECKASM-DAG-NOT: .size g1
 
 extern __thread int __libc_errno __attribute__ ((alias ("TL_WITH_ALIAS")));
 // CHECKBASIC-DAG: @__libc_errno = thread_local alias i32* @TL_WITH_ALIAS
+// CHECKASM-DAG: .globl __libc_errno
+// CHECKASM-DAG: __libc_errno = TL_WITH_ALIAS
+// CHECKASM-DAG-NOT: .size __libc_errno
 
 void f0(void) { }
 extern void f1(void);
 extern void f1(void) __attribute((alias("f0")));
 // CHECKBASIC-DAG: @f1 = alias void ()* @f0
 // CHECKBASIC-DAG: @test8_foo = weak alias bitcast (void ()* @test8_bar to void (...)*)
 // CHECKBASIC-DAG: @test8_zed = alias bitcast (void ()* @test8_bar to void (...)*)
 // CHECKBASIC-DAG: @test9_zed = alias void ()* @test9_bar