Fix inline functions on windows (#405)

* Add inline function test

* Provide a partial fix for the inline problem, but not the stdio-specific problem.

* Disable tests again because test environment can't find legacy stdio lib

* Fix permissions.

src/tcwrapper.cpp

@@ -857,22 +857,38 @@ static void optimizemodule(TerraTarget * TT, llvm::Module * M) {
     //in some cases clang will mark stuff AvailableExternally (e.g. atoi on linux)
     //the linker will then delete it because it is not used.
     //switching it to WeakODR means that the linker will keep it even if it is not used
+    std::vector<llvm::Constant*> usedArray;
+
     for(llvm::Module::iterator it = M->begin(), end = M->end();
         it != end;
         ++it) {
         llvm::Function * fn = &*it;
         if(fn->hasAvailableExternallyLinkage()) {
             fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
         }
+    #ifdef _WIN32 // On windows, the optimizer will delete LinkOnce functions that are unused
+        usedArray.push_back(fn);
+    #endif
     #if LLVM_VERSION >= 35
         if(fn->hasDLLImportStorageClass()) //clear dll import linkage because it messes up the jit on window
             fn->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
     #else
         if(fn->hasDLLImportLinkage()) //clear dll import linkage because it messes up the jit on window
             fn->setLinkage(llvm::GlobalValue::ExternalLinkage);
-
     #endif
     }
+
+    if(usedArray.size() > 0) {
+      auto* i8PtrType = llvm::Type::getInt8PtrTy(M->getContext());
+      for(auto& elem : usedArray)
+        elem = llvm::ConstantExpr::getBitCast(elem, i8PtrType);
+
+      auto* arrayType = llvm::ArrayType::get(i8PtrType, usedArray.size());
+      auto* llvmUsed = new llvm::GlobalVariable(*M, arrayType, false, llvm::GlobalValue::AppendingLinkage,
+        llvm::ConstantArray::get(arrayType, usedArray), "llvm.used");
+      llvmUsed->setSection("llvm.metadata");
+    }
+
     M->setTargetTriple(TT->Triple); //suppress warning that occur due to unmatched os versions
     PassManager opt;
     llvmutil_addtargetspecificpasses(&opt, TT->tm);

tests/benchmark_nbody.t

@@ -1,11 +1,12 @@
 local C = terralib.includecstring[[
 
 #include <math.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 ]]
 
+C.printf = terralib.externfunction("printf", terralib.types.funcpointer(rawstring,int,true))
+
 pi = 3.141592653589793
 solar_mass = (4 * pi * pi)
 days_per_year = 365.24

tests/class2.t

@@ -45,6 +45,4 @@ end
 local test = require("test")
 test.eq(foo(),9)
 
-terralib.saveobj("class2", "executable", {
-	main = terra() S.printf("foo() = %d\n", foo()) end,
-}, (jit.os == "Windows" and "\\legacy_stdio_definitions.lib" or nil))
+terralib.saveobj("class2", "executable", {main = terra() S.printf("foo() = %d\n", foo()) end})

tests/inline_c.t

@@ -0,0 +1,9 @@
+C = terralib.includecstring[[inline int testfunc(int a, int b) { return a + b; }]]
+
+terra foobar() : int
+	var a : int = 5
+  return C.testfunc(a, 9)
+end
+assert(foobar() == 14)
+
+terralib.saveobj("inline_c.exe", {main = foobar})

tests/run

@@ -6,13 +6,13 @@ local lscmd
 if ffi.os == "Windows" then
     lscmd = "cmd /c dir /b /s"
 
-    -- These tests produce spurious output due to a bug in LLVM on windows
-    table.insert(skip, "speed.t")
-    table.insert(skip, "class2.t")
     -- FIXME: https://github.com/zdevito/terra/issues/401
-    table.insert(skip, "benchmark_fannkuchredux.t")
+    table.insert(skip, "class2.t")
+    table.insert(skip, "stdio.t")
+    table.insert(skip, "speed.t")
     table.insert(skip, "benchmark_nbody.t")
-    -- FIXME: https://github.com/zdevito/terra/issues/404
+    table.insert(skip, "benchmark_fannkuchredux.t")
+    -- Disabled due to non-deterministic failures on certain branches: https://github.com/zdevito/terra/issues/404
     table.insert(skip, "leaktest.t")
 else
     lscmd = "find . | cut -c 3-"

tests/speed.t

@@ -1,7 +1,7 @@
-local c = terralib.includecstring [[ 
-    #include <stdio.h>
+local C = terralib.includecstring [[ 
     #include <stdlib.h>
 ]]
+C.printf = terralib.externfunction("printf", terralib.types.funcpointer(rawstring,int,true))
 
 terra doit(N : int64)
     var cur,last = 1ULL,1ULL
@@ -13,18 +13,18 @@ end
 terra main(argc : int, argv : &&int8)
     var N = 4ULL
     if argc == 2 then
-        N = c.atoi(argv[1])
+        N = C.atoi(argv[1])
     end
     var result = doit(N)
-    c.printf("%lld\n",result)
+    C.printf("%lld\n",result)
 end
 
 terra what()
-	return c.atoi("54")
+	return C.atoi("54")
 end
 
 local test = require("test")
 print(what())
 print(test.time( function() doit:compile() end))
 print(test.time( function() doit(100000000) end))
-print(test.time( function() terralib.saveobj("speed",{main = main}, (jit.os == "Windows" and "\\legacy_stdio_definitions.lib" or nil)) end))
+print(test.time( function() terralib.saveobj("speed",{main = main}, (jit.os == "Windows" and {"\\legacy_stdio_definitions.lib"} or nil)) end))

tests/stdio.t

@@ -0,0 +1,12 @@
+C = terralib.includecstring[[
+#include <stdio.h>
+inline int testfunc(int a, int b) { return a + b; }]]
+
+terra foobar() : int
+	var a : int = 5
+  C.printf("C: %i\n", C.testfunc(a, 9))
+  return C.testfunc(a, 9)
+end
+assert(foobar() == 14)
+
+terralib.saveobj("stdio.exe", {main = foobar})