Add dependency for LLVM. Fixes #1611

This adds a depdendncy wrapper for llvm-config based on the wxwidgets
dependency. IT handles libs, version, include dir, and the llvm unique
concept of components. These components are individual pieces of the
LLVM library that may or may not be available depending on the platform.

2 files changed, 86 insertions, 0 deletions

diff --git a/test cases/frameworks/15 llvm/meson.build b/test cases/frameworks/15 llvm/meson.build
new file mode 100644
index 000000000..582ff3740
--- /dev/null
+++ b/test cases/frameworks/15 llvm/meson.build
@@ -0,0 +1,10 @@
+project('llvmtest', ['c', 'cpp'], default_options : ['c_std=c99'])
+
+llvm_dep = dependency(
+  'llvm',
+  modules : ['bitwriter', 'asmprinter', 'executionengine', 'target',
+             'mcjit', 'nativecodegen'],
+  required : true,
+)
+
+executable('sum', 'sum.c',  dependencies : llvm_dep)
diff --git a/test cases/frameworks/15 llvm/sum.c b/test cases/frameworks/15 llvm/sum.c
new file mode 100644
index 000000000..a93588e5e
--- /dev/null
+++ b/test cases/frameworks/15 llvm/sum.c
@@ -0,0 +1,76 @@
+/** This code is public domain, and taken from 
+ * https://github.com/paulsmith/getting-started-llvm-c-api/blob/master/sum.c
+ */
+/**
+ * LLVM equivalent of:
+ *
+ * int sum(int a, int b) {
+ *     return a + b;
+ * }
+ */
+
+#include <llvm-c/Core.h>
+#include <llvm-c/ExecutionEngine.h>
+#include <llvm-c/Target.h>
+#include <llvm-c/Analysis.h>
+#include <llvm-c/BitWriter.h>
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char const *argv[]) {
+    LLVMModuleRef mod = LLVMModuleCreateWithName("my_module");
+
+    LLVMTypeRef param_types[] = { LLVMInt32Type(), LLVMInt32Type() };
+    LLVMTypeRef ret_type = LLVMFunctionType(LLVMInt32Type(), param_types, 2, 0);
+    LLVMValueRef sum = LLVMAddFunction(mod, "sum", ret_type);
+
+    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(sum, "entry");
+
+    LLVMBuilderRef builder = LLVMCreateBuilder();
+    LLVMPositionBuilderAtEnd(builder, entry);
+    LLVMValueRef tmp = LLVMBuildAdd(builder, LLVMGetParam(sum, 0), LLVMGetParam(sum, 1), "tmp");
+    LLVMBuildRet(builder, tmp);
+
+    char *error = NULL;
+    LLVMVerifyModule(mod, LLVMAbortProcessAction, &error);
+    LLVMDisposeMessage(error);
+
+    LLVMExecutionEngineRef engine;
+    error = NULL;
+    LLVMLinkInMCJIT();
+    LLVMInitializeNativeAsmPrinter();
+    LLVMInitializeNativeTarget();
+    if (LLVMCreateExecutionEngineForModule(&engine, mod, &error) != 0) {
+        fprintf(stderr, "failed to create execution engine\n");
+        abort();
+    }
+    if (error) {
+        fprintf(stderr, "error: %s\n", error);
+        LLVMDisposeMessage(error);
+        exit(EXIT_FAILURE);
+    }
+
+    if (argc < 3) {
+        fprintf(stderr, "usage: %s x y\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+    long long x = strtoll(argv[1], NULL, 10);
+    long long y = strtoll(argv[2], NULL, 10);
+
+    LLVMGenericValueRef args[] = {
+        LLVMCreateGenericValueOfInt(LLVMInt32Type(), x, 0),
+        LLVMCreateGenericValueOfInt(LLVMInt32Type(), y, 0)
+    };
+    LLVMGenericValueRef res = LLVMRunFunction(engine, sum, 2, args);
+    printf("%d\n", (int)LLVMGenericValueToInt(res, 0));
+
+    // Write out bitcode to file
+    if (LLVMWriteBitcodeToFile(mod, "sum.bc") != 0) {
+        fprintf(stderr, "error writing bitcode to file, skipping\n");
+    }
+
+    LLVMDisposeBuilder(builder);
+    LLVMDisposeExecutionEngine(engine);
+}