fix Executor::initializeGlobals for aliases pointing to another alias

5 files changed, 84 insertions, 4 deletions

diff --git a/lib/Core/Executor.cpp b/lib/Core/Executor.cpp
index ef996e7e..7aaaa87c 100644
--- a/lib/Core/Executor.cpp
+++ b/lib/Core/Executor.cpp
@@ -736,11 +736,19 @@ void Executor::initializeGlobals(ExecutionState &state) {
   }
   
   // link aliases to their definitions (if bound)
-  for (Module::alias_iterator i = m->alias_begin(), ie = m->alias_end(); 
-       i != ie; ++i) {
+  for (auto i = m->alias_begin(), ie = m->alias_end(); i != ie; ++i) {
     // Map the alias to its aliasee's address. This works because we have
-    // addresses for everything, even undefined functions. 
-    globalAddresses.insert(std::make_pair(&*i, evalConstant(i->getAliasee())));
+    // addresses for everything, even undefined functions.
+
+    // Alias may refer to other alias, not necessarily known at this point.
+    // Thus, resolve to real alias directly.
+    const GlobalAlias *alias = &*i;
+    while (const auto *ga = dyn_cast<GlobalAlias>(alias->getAliasee())) {
+      assert(ga != alias && "alias pointing to itself");
+      alias = ga;
+    }
+
+    globalAddresses.insert(std::make_pair(&*i, evalConstant(alias->getAliasee())));
   }
 
   // once all objects are allocated, do the actual initialization
diff --git a/test/Feature/Alias.c b/test/Feature/Alias.c
index 09abb3e0..f83652d8 100644
--- a/test/Feature/Alias.c
+++ b/test/Feature/Alias.c
@@ -10,6 +10,10 @@
 int b = 52;
 extern int a __attribute__((alias("b")));
 
+// alias for alias
+// NOTE: this does not have to be before foo is known
+extern int foo2() __attribute__((alias("foo")));
+
 // alias for function
 int __foo() { return 52; }
 extern int foo() __attribute__((alias("__foo")));
@@ -19,6 +23,7 @@ int *c = &a;
 int main() {
   assert(a == 52);
   assert(foo() == 52);
+  assert(foo2() == 52);
   assert(*c == 52);
 
   return 0;
diff --git a/test/regression/2018-10-28-alias-to-alias.leq36.ll b/test/regression/2018-10-28-alias-to-alias.leq36.ll
new file mode 100644
index 00000000..2d4bd803
--- /dev/null
+++ b/test/regression/2018-10-28-alias-to-alias.leq36.ll
@@ -0,0 +1,21 @@
+; REQUIRES: lt-llvm-3.7
+; RUN: rm -rf %t.klee-out
+; RUN: llvm-as -f %s -o - | %klee --output-dir=%t.klee-out
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; @foo is not known yet
+@foo2 = alias i32 (...)* @foo
+@foo = alias bitcast (i32 ()* @__foo to i32 (...)*)
+
+define i32 @__foo() {
+entry:
+  ret i32 42
+}
+
+define i32 @main() {
+entry:
+  call i32 (...)* @foo()
+  call i32 (...)* @foo2()
+  ret i32 0
+}
diff --git a/test/regression/2018-10-28-alias-to-alias.leq37.ll b/test/regression/2018-10-28-alias-to-alias.leq37.ll
new file mode 100644
index 00000000..9ed5aa47
--- /dev/null
+++ b/test/regression/2018-10-28-alias-to-alias.leq37.ll
@@ -0,0 +1,23 @@
+; LLVM 3.7 no longer accepts '*' with a 'call'
+; REQUIRES: geq-llvm-3.7
+; REQUIRES: lt-llvm-3.8
+; RUN: rm -rf %t.klee-out
+; RUN: llvm-as -f %s -o - | %klee --output-dir=%t.klee-out
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; @foo is not known yet
+@foo2 = alias i32 (...)* @foo
+@foo = alias bitcast (i32 ()* @__foo to i32 (...)*)
+
+define i32 @__foo() {
+entry:
+  ret i32 42
+}
+
+define i32 @main() {
+entry:
+  call i32 (...) @foo()
+  call i32 (...) @foo2()
+  ret i32 0
+}
diff --git a/test/regression/2018-10-28-alias-to-alias.ll b/test/regression/2018-10-28-alias-to-alias.ll
new file mode 100644
index 00000000..0e9415d8
--- /dev/null
+++ b/test/regression/2018-10-28-alias-to-alias.ll
@@ -0,0 +1,23 @@
+; LLVM 3.8 requires a type as the first argument to 'alias'
+; LLVM 3.7 no longer accepts '*' with a 'call'
+; REQUIRES: geq-llvm-3.8
+; RUN: rm -rf %t.klee-out
+; RUN: llvm-as -f %s -o - | %klee --output-dir=%t.klee-out
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; @foo is not known yet
+@foo2 = alias i32 (...), i32 (...)* @foo
+@foo = alias i32 (...), bitcast (i32 ()* @__foo to i32 (...)*)
+
+define i32 @__foo() {
+entry:
+  ret i32 42
+}
+
+define i32 @main() {
+entry:
+  call i32 (...) @foo()
+  call i32 (...) @foo2()
+  ret i32 0
+}