Verify LLVM module before writing, and add new flag to disable it (fo…

…r debugging)
dosisod · Jan 2, 2022 · c185a69 · c185a69
1 parent 656c08e
commit c185a69
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Showing 9 changed files with 51 additions and 14 deletions.
diff --git a/skull/build_data.h b/skull/build_data.h
@@ -15,6 +15,7 @@ typedef struct {
 	_Bool optimize1;
 	_Bool optimize2;
 	_Bool optimize3;
+	_Bool llvm_no_verify;
 } BuildData;
 
 extern BuildData BUILD_DATA;
diff --git a/skull/cli.c b/skull/cli.c
@@ -219,6 +219,9 @@ static bool parse_long_option(const char *arg) {
 	else if (strcmp(arg, "werror") == 0) {
 		set_bool_flag(&BUILD_DATA.werror, "--werror");
 	}
+	else if (strcmp(arg, "llvm-no-verify") == 0) {
+		set_bool_flag(&BUILD_DATA.llvm_no_verify, "--llvm-no-verify");
+	}
 	else {
 		fprintf(stderr, "skull: unknown option \"--%s\"\n", arg);
 		return true;

diff --git a/skull/codegen/llvm/core.c b/skull/codegen/llvm/core.c
@@ -47,8 +47,8 @@ static Expr gen_node(const AstNode **node) {
 		case AST_NODE_EXPR:
 			gen_expr_func_call((*node)->expr->lhs.func_call); break;
 		case AST_NODE_NOOP: gen_stmt_noop(&(*node)->token->location); break;
-		case AST_NODE_BREAK: gen_stmt_break(); break;
-		case AST_NODE_CONTINUE: gen_stmt_continue(); break;
+		case AST_NODE_BREAK: return gen_stmt_break();
+		case AST_NODE_CONTINUE: return gen_stmt_continue();
 		default: break;
 	}
 

diff --git a/skull/codegen/llvm/flow.c b/skull/codegen/llvm/flow.c
@@ -222,12 +222,24 @@ static void gen_control_if_(
 	LLVMPositionBuilderAtEnd(SKULL_STATE_LLVM.builder, end);
 }
 
-void gen_stmt_break(void) {
-	LLVMBuildBr(SKULL_STATE_LLVM.builder, SKULL_STATE_LLVM.current_while_end);
+Expr gen_stmt_break(void) {
+	return (Expr){
+		.value = LLVMBuildBr(
+			SKULL_STATE_LLVM.builder,
+			SKULL_STATE_LLVM.current_while_end
+		),
+		.type = TYPE_VOID
+	};
 }
 
-void gen_stmt_continue(void) {
-	LLVMBuildBr(SKULL_STATE_LLVM.builder, SKULL_STATE_LLVM.current_while_cond);
+Expr gen_stmt_continue(void) {
+	return (Expr){
+		.value = LLVMBuildBr(
+			SKULL_STATE_LLVM.builder,
+			SKULL_STATE_LLVM.current_while_cond
+		),
+		.type = TYPE_VOID
+	};
 }
 
 /*

diff --git a/skull/codegen/llvm/flow.h b/skull/codegen/llvm/flow.h
@@ -7,9 +7,9 @@ typedef struct Location Location;
 
 Expr gen_stmt_return(const AstNode *);
 Expr gen_stmt_unreachable(void);
+Expr gen_stmt_break(void);
+Expr gen_stmt_continue(void);
 void gen_stmt_implicit_main_return(const Location *);
 void gen_stmt_noop(const Location *);
-void gen_stmt_break(void);
-void gen_stmt_continue(void);
 void gen_control_while(const AstNode *);
 void gen_control_if(const AstNode **);
diff --git a/skull/codegen/llvm/write.c b/skull/codegen/llvm/write.c
@@ -6,6 +6,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <llvm-c/Analysis.h>
 #include <llvm-c/Core.h>
 #include <llvm-c/DebugInfo.h>
 #include <llvm-c/Target.h>
@@ -21,6 +22,7 @@
 #include "skull/common/str.h"
 
 static bool create_ll_file(const char *);
+static bool verify_llvm(void);
 static bool optimize_llvm(void);
 static int run_llc(void);
 static int run_cc(char *);
@@ -34,6 +36,10 @@ static int check_directory(char *);
 Write LLVM code to `filename`, return whether error occured.
 */
 bool write_file_llvm(const char *filename) {
+	if (BUILD_DATA.debug) LLVMDIBuilderFinalize(DEBUG_INFO.builder);
+
+	if (!BUILD_DATA.llvm_no_verify && verify_llvm()) return true;
+
 	if (BUILD_DATA.optimize1 || BUILD_DATA.optimize2 || BUILD_DATA.optimize3) {
 		if (optimize_llvm()) return true;
 	}
@@ -51,6 +57,24 @@ bool write_file_llvm(const char *filename) {
 	return err || run_cc(binary_name);
 }
 
+static bool verify_llvm(void) {
+	char *err_msg = NULL;
+
+	const bool err = LLVMVerifyModule(
+		SKULL_STATE_LLVM.module,
+		LLVMReturnStatusAction,
+		&err_msg
+	);
+
+	if (err) {
+		fprintf(stderr, "skull: error while verifying LLVM: %s\n", err_msg);
+	}
+
+	LLVMDisposeMessage(err_msg);
+
+	return err;
+}
+
 static bool optimize_llvm(void) {
 	LLVMInitializeAllTargetInfos();
 
@@ -100,8 +124,6 @@ static bool optimize_llvm(void) {
 }
 
 static bool create_ll_file(const char *filename) {
-	if (BUILD_DATA.debug) LLVMDIBuilderFinalize(DEBUG_INFO.builder);
-
 	if (strcmp(filename, "-") == 0) {
 		char *msg = LLVMPrintModuleToString(SKULL_STATE_LLVM.module);
 		printf("%s", msg);

diff --git a/test/sh/flow/break.sk.ll b/test/sh/flow/break.sk.ll
@@ -5,12 +5,11 @@ define i64 @.break() {
 entry:
   br label %while_cond
 
-while_cond:                                       ; preds = %while_loop, %entry
+while_cond:                                       ; preds = %entry
   br i1 true, label %while_loop, label %while_end
 
 while_loop:                                       ; preds = %while_cond
   br label %while_end
-  br label %while_cond
 
 while_end:                                        ; preds = %while_loop, %while_cond
   ret i64 0

diff --git a/test/sh/flow/continue.sk.ll b/test/sh/flow/continue.sk.ll
@@ -5,12 +5,11 @@ define i64 @.continue() {
 entry:
   br label %while_cond
 
-while_cond:                                       ; preds = %while_loop, %while_loop, %entry
+while_cond:                                       ; preds = %while_loop, %entry
   br i1 true, label %while_loop, label %while_end
 
 while_loop:                                       ; preds = %while_cond
   br label %while_cond
-  br label %while_cond
 
 while_end:                                        ; preds = %while_cond
   ret i64 0

diff --git a/test/sh/main.sh b/test/sh/main.sh
@@ -130,6 +130,7 @@ test_skull "duplicate_arg.sh -O2" "-O2 -O2"
 test_skull "duplicate_arg.sh -O3" "-O3 -O3"
 test_skull "duplicate_arg.sh --c-backend" "--c-backend --c-backend"
 test_skull "duplicate_arg.sh --werror" "--werror --werror"
+test_skull "duplicate_arg.sh --llvm-no-verify" "--llvm-no-verify --llvm-no-verify"
 test_skull "warn_dash_dash_no_args.sh" "--"
 test_skull "dash_o_expect_filename.sh" "-o"
 test_skull "dash_o_no_binary.sh" "./test/sh/skull/dummy.sk -o -"