[LLVM-C] Improve Bindings For Aliases

Summary: Add wrappers for a module's alias iterators and a getter and setter for the aliasee value.

Reviewers: whitequark, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits, harlanhaskins

Differential Revision: https://reviews.llvm.org/D46808

llvm-svn: 332826

1 files changed, 88 insertions, 6 deletions

diff --git a/llvm/tools/llvm-c-test/echo.cpp b/llvm/tools/llvm-c-test/echo.cpp
index ca3a1be0684..a9cd4cf5cbb 100644
--- a/llvm/tools/llvm-c-test/echo.cpp
+++ b/llvm/tools/llvm-c-test/echo.cpp
@@ -248,10 +248,19 @@ static LLVMValueRef clone_constant_impl(LLVMValueRef Cst, LLVMModuleRef M) {
     // Try global variable
     if (LLVMIsAGlobalVariable(Cst)) {
       check_value_kind(Cst, LLVMGlobalVariableValueKind);
-      LLVMValueRef Dst  = LLVMGetNamedGlobal(M, Name);
+      LLVMValueRef Dst = LLVMGetNamedGlobal(M, Name);
       if (Dst)
         return Dst;
-      report_fatal_error("Could not find function");
+      report_fatal_error("Could not find variable");
+    }
+
+    // Try global alias
+    if (LLVMIsAGlobalAlias(Cst)) {
+      check_value_kind(Cst, LLVMGlobalAliasValueKind);
+      LLVMValueRef Dst = LLVMGetNamedGlobalAlias(M, Name, NameLen);
+      if (Dst)
+        return Dst;
+      report_fatal_error("Could not find alias");
     }
 
     fprintf(stderr, "Could not find @%s\n", Name);
@@ -822,6 +831,8 @@ struct FunCloner {
 };
 
 static void declare_symbols(LLVMModuleRef Src, LLVMModuleRef M) {
+  auto Ctx = LLVMGetModuleContext(M);
+
   LLVMValueRef Begin = LLVMGetFirstGlobal(Src);
   LLVMValueRef End = LLVMGetLastGlobal(Src);
 
@@ -860,11 +871,9 @@ FunDecl:
   if (!Begin) {
     if (End != nullptr)
       report_fatal_error("Range has an end but no beginning");
-    return;
+    goto AliasDecl;
   }
 
-  auto Ctx = LLVMGetModuleContext(M);
-
   Cur = Begin;
   Next = nullptr;
   while (true) {
@@ -900,6 +909,40 @@ FunDecl:
 
     Cur = Next;
   }
+
+AliasDecl:
+  Begin = LLVMGetFirstGlobalAlias(Src);
+  End = LLVMGetLastGlobalAlias(Src);
+  if (!Begin) {
+    if (End != nullptr)
+      report_fatal_error("Range has an end but no beginning");
+    return;
+  }
+
+  Cur = Begin;
+  Next = nullptr;
+  while (true) {
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
+    if (LLVMGetNamedGlobalAlias(M, Name, NameLen))
+      report_fatal_error("Global alias already cloned");
+    LLVMTypeRef CurType = TypeCloner(M).Clone(Cur);
+    // FIXME: Allow NULL aliasee.
+    LLVMAddAlias(M, CurType, LLVMGetUndef(CurType), Name);
+
+    Next = LLVMGetNextGlobalAlias(Cur);
+    if (Next == nullptr) {
+      if (Cur != End)
+        report_fatal_error("");
+      break;
+    }
+
+    LLVMValueRef Prev = LLVMGetPreviousGlobalAlias(Next);
+    if (Prev != Cur)
+      report_fatal_error("Next.Previous global is not Current");
+
+    Cur = Next;
+  }
 }
 
 static void clone_symbols(LLVMModuleRef Src, LLVMModuleRef M) {
@@ -953,7 +996,7 @@ FunClone:
   if (!Begin) {
     if (End != nullptr)
       report_fatal_error("Range has an end but no beginning");
-    return;
+    goto AliasClone;
   }
 
   Cur = Begin;
@@ -991,6 +1034,45 @@ FunClone:
 
     Cur = Next;
   }
+
+AliasClone:
+  Begin = LLVMGetFirstGlobalAlias(Src);
+  End = LLVMGetLastGlobalAlias(Src);
+  if (!Begin) {
+    if (End != nullptr)
+      report_fatal_error("Range has an end but no beginning");
+    return;
+  }
+
+  Cur = Begin;
+  Next = nullptr;
+  while (true) {
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
+    LLVMValueRef Alias = LLVMGetNamedGlobalAlias(M, Name, NameLen);
+    if (!Alias)
+      report_fatal_error("Global alias must have been declared already");
+
+    if (LLVMValueRef Aliasee = LLVMAliasGetAliasee(Cur)) {
+      LLVMAliasSetAliasee(Alias, clone_constant(Aliasee, M));
+    }
+
+    LLVMSetLinkage(Alias, LLVMGetLinkage(Cur));
+    LLVMSetUnnamedAddress(Alias, LLVMGetUnnamedAddress(Cur));
+
+    Next = LLVMGetNextGlobalAlias(Cur);
+    if (Next == nullptr) {
+      if (Cur != End)
+        report_fatal_error("Last global alias does not match End");
+      break;
+    }
+
+    LLVMValueRef Prev = LLVMGetPreviousGlobalAlias(Next);
+    if (Prev != Cur)
+      report_fatal_error("Next.Previous global alias is not Current");
+
+    Cur = Next;
+  }
 }
 
 int llvm_echo(void) {