Merge remote-tracking branch 'origin/master' into llvm12

CMakeLists.txt

@@ -87,10 +87,15 @@ option(ZIG_TEST_COVERAGE "Build Zig with test coverage instrumentation" OFF)
 set(ZIG_TARGET_TRIPLE "native" CACHE STRING "arch-os-abi to output binaries for")
 set(ZIG_TARGET_MCPU "baseline" CACHE STRING "-mcpu parameter to output binaries for")
 set(ZIG_EXECUTABLE "" CACHE STRING "(when cross compiling) path to already-built zig binary")
-set(ZIG_PREFER_LLVM_CONFIG off CACHE BOOL "(when cross compiling) use llvm-config to find target llvm dependencies if needed")
 set(ZIG_SINGLE_THREADED off CACHE BOOL "limit the zig compiler to use only 1 thread")
 set(ZIG_OMIT_STAGE2 off CACHE BOOL "omit the stage2 backend from stage1")
 
+if("${ZIG_TARGET_TRIPLE}" STREQUAL "native")
+    set(ZIG_USE_LLVM_CONFIG ON CACHE BOOL "use llvm-config to find LLVM libraries")
+else()
+    set(ZIG_USE_LLVM_CONFIG OFF CACHE BOOL "use llvm-config to find LLVM libraries")
+endif()
+
 find_package(llvm)
 find_package(clang)
 find_package(lld)

cmake/Findllvm.cmake

@@ -63,7 +63,7 @@ if(ZIG_PREFER_CLANG_CPP_DYLIB)
   if("${LLVM_CONFIG_VERSION}" VERSION_GREATER 13)
     message(FATAL_ERROR "expected LLVM 12.x but found ${LLVM_CONFIG_VERSION} using ${LLVM_CONFIG_EXE}")
   endif()
-elseif(("${ZIG_TARGET_TRIPLE}" STREQUAL "native") OR ZIG_PREFER_LLVM_CONFIG)
+elseif(ZIG_USE_LLVM_CONFIG)
   find_program(LLVM_CONFIG_EXE
       NAMES llvm-config-12 llvm-config-12.0 llvm-config120 llvm-config12 llvm-config
       PATHS

doc/langref.html.in

@@ -684,7 +684,7 @@ pub fn main() void {
       {#header_close#}
       {#header_open|String Literals and Unicode Code Point Literals#}
       <p>
-      String literals are single-item constant {#link|Pointers#} to null-terminated byte arrays.
+      String literals are constant single-item {#link|Pointers#} to null-terminated byte arrays.
       The type of string literals encodes both the length, and the fact that they are null-terminated,
       and thus they can be {#link|coerced|Type Coercion#} to both {#link|Slices#} and
       {#link|Null-Terminated Pointers|Sentinel-Terminated Pointers#}.
@@ -1783,7 +1783,7 @@ comptime {
     expect(message.len == 5);
 }
 
-// A string literal is a pointer to an array literal.
+// A string literal is a single-item pointer to an array literal.
 const same_message = "hello";
 
 comptime {
@@ -1989,15 +1989,15 @@ test "null terminated array" {
 
       {#header_open|Pointers#}
       <p>
-      Zig has two kinds of pointers:
+      Zig has two kinds of pointers: single-item and many-item.
       </p>
       <ul>
-          <li>{#syntax#}*T{#endsyntax#} - pointer to exactly one item.
+          <li>{#syntax#}*T{#endsyntax#} - single-item pointer to exactly one item.
             <ul>
               <li>Supports deref syntax: {#syntax#}ptr.*{#endsyntax#}</li>
             </ul>
           </li>
-          <li>{#syntax#}[*]T{#endsyntax#} - pointer to unknown number of items.
+          <li>{#syntax#}[*]T{#endsyntax#} - many-item pointer to unknown number of items.
             <ul>
               <li>Supports index syntax: {#syntax#}ptr[i]{#endsyntax#}</li>
               <li>Supports slice syntax: {#syntax#}ptr[start..end]{#endsyntax#}</li>
@@ -2009,7 +2009,7 @@ test "null terminated array" {
       </ul>
       <p>These types are closely related to {#link|Arrays#} and {#link|Slices#}:</p>
         <ul>
-            <li>{#syntax#}*[N]T{#endsyntax#} - pointer to N items, same as single-item pointer to array.
+            <li>{#syntax#}*[N]T{#endsyntax#} - pointer to N items, same as single-item pointer to an array.
             <ul>
                 <li>Supports index syntax: {#syntax#}array_ptr[i]{#endsyntax#}</li>
                 <li>Supports slice syntax: {#syntax#}array_ptr[start..end]{#endsyntax#}</li>
@@ -2038,7 +2038,7 @@ test "address of syntax" {
     // Dereference a pointer:
     expect(x_ptr.* == 1234);
 
-    // When you get the address of a const variable, you get a const pointer to a single item.
+    // When you get the address of a const variable, you get a const single-item pointer.
     expect(@TypeOf(x_ptr) == *const i32);
 
     // If you want to mutate the value, you'd need an address of a mutable variable:
@@ -2051,7 +2051,7 @@ test "address of syntax" {
 
 test "pointer array access" {
     // Taking an address of an individual element gives a
-    // pointer to a single item. This kind of pointer
+    // single-item pointer. This kind of pointer
     // does not support pointer arithmetic.
     var array = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
     const ptr = &array[2];
@@ -2320,8 +2320,8 @@ test "basic slices" {
     expect(&slice[0] == &array[0]);
     expect(slice.len == array.len);
 
-    // Using the address-of operator on a slice gives a pointer to a single
-    // item, while using the `ptr` field gives an unknown length pointer.
+    // Using the address-of operator on a slice gives a single-item pointer,
+    // while using the `ptr` field gives a many-item pointer.
     expect(@TypeOf(slice.ptr) == [*]i32);
     expect(@TypeOf(&slice[0]) == *i32);
     expect(@ptrToInt(slice.ptr) == @ptrToInt(&slice[0]));
@@ -5244,8 +5244,7 @@ test "*[N]T to []T" {
     expect(std.mem.eql(f32, x2, &[2]f32{ 1.2, 3.4 }));
 }
 
-// Single-item pointers to arrays can be coerced to
-// unknown length pointers.
+// Single-item pointers to arrays can be coerced to many-item pointers.
 test "*[N]T to [*]T" {
     var buf: [5]u8 = "hello".*;
     const x: [*]u8 = &buf;
@@ -9853,7 +9852,7 @@ const c = @cImport({
       </p>
       <p>
       When importing C header files, it is ambiguous whether pointers should be translated as
-      single-item pointers ({#syntax#}*T{#endsyntax#}) or unknown-length pointers ({#syntax#}[*]T{#endsyntax#}).
+      single-item pointers ({#syntax#}*T{#endsyntax#}) or many-item pointers ({#syntax#}[*]T{#endsyntax#}).
       C pointers are a compromise so that Zig code can utilize translated header files directly.
       </p>
       <p>{#syntax#}[*c]T{#endsyntax#} - C pointer.</p>

src/link/MachO.zig

@@ -835,7 +835,10 @@ fn linkWithLLD(self: *MachO, comp: *Compilation) !void {
                             std.process.exit(1);
                         }
                     },
-                    else => std.process.abort(),
+                    else => {
+                        log.err("{s} terminated", .{ argv.items[0] });
+                        return error.LLDCrashed;
+                    },
                 }
             } else {
                 child.stdin_behavior = .Ignore;

src/stage1/codegen.cpp

@@ -487,6 +487,53 @@ static LLVMValueRef make_fn_llvm_value(CodeGen *g, ZigFn *fn) {
         addLLVMFnAttr(llvm_fn, "noreturn");
     }
 
+    if (!calling_convention_allows_zig_types(cc)) {
+        // A simplistic and desperate attempt at making the compiler respect the
+        // target ABI for return types.
+        // This is just enough to avoid miscompiling the test suite, it will be
+        // better in stage2.
+        ZigType *int_type = return_type->id == ZigTypeIdInt ? return_type :
+                return_type->id == ZigTypeIdEnum ? return_type->data.enumeration.tag_int_type :
+                nullptr;
+
+        if (int_type != nullptr) {
+            const bool is_signed = int_type->data.integral.is_signed;
+            const uint32_t bit_width = int_type->data.integral.bit_count;
+            bool should_extend = false;
+
+            // Rough equivalent of Clang's isPromotableIntegerType.
+            switch (bit_width) {
+                case 1: // bool
+                case 8: // {un,}signed char
+                case 16: // {un,}signed short
+                    should_extend = true;
+                    break;
+                default:
+                    break;
+            }
+
+            switch (g->zig_target->arch) {
+                case ZigLLVM_sparcv9:
+                case ZigLLVM_riscv64:
+                case ZigLLVM_ppc64:
+                case ZigLLVM_ppc64le:
+                    // Always extend to the register width.
+                    should_extend = bit_width < 64;
+                    break;
+                default:
+                    break;
+            }
+
+            // {zero,sign}-extend the result.
+            if (should_extend) {
+                if (is_signed)
+                    addLLVMAttr(llvm_fn, 0, "signext");
+                else
+                    addLLVMAttr(llvm_fn, 0, "zeroext");
+            }
+        }
+    }
+
     if (fn->body_node != nullptr) {
         maybe_export_dll(g, llvm_fn, linkage);
 

test/stage1/c_abi/cfuncs.c

@@ -24,6 +24,16 @@ void zig_f32(float);
 void zig_f64(double);
 void zig_five_floats(float, float, float, float, float);
 
+bool zig_ret_bool();
+uint8_t zig_ret_u8();
+uint16_t zig_ret_u16();
+uint32_t zig_ret_u32();
+uint64_t zig_ret_u64();
+int8_t zig_ret_i8();
+int16_t zig_ret_i16();
+int32_t zig_ret_i32();
+int64_t zig_ret_i64();
+
 void zig_ptr(void *);
 
 void zig_bool(bool);
@@ -119,6 +129,20 @@ void run_c_tests(void) {
         assert_or_panic(res.d == 23);
         assert_or_panic(res.e == 24);
     }
+
+    {
+        assert_or_panic(zig_ret_bool() == 1);
+
+        assert_or_panic(zig_ret_u8() == 0xff);
+        assert_or_panic(zig_ret_u16() == 0xffff);
+        assert_or_panic(zig_ret_u32() == 0xffffffff);
+        assert_or_panic(zig_ret_u64() == 0xffffffffffffffff);
+
+        assert_or_panic(zig_ret_i8() == -1);
+        assert_or_panic(zig_ret_i16() == -1);
+        assert_or_panic(zig_ret_i32() == -1);
+        assert_or_panic(zig_ret_i64() == -1);
+    }
 }
 
 void c_u8(uint8_t x) {
@@ -236,3 +260,31 @@ void c_big_struct_floats(Vector5 vec) {
     assert_or_panic(vec.w == 69);
     assert_or_panic(vec.q == 55);
 }
+
+bool c_ret_bool() {
+    return 1;
+}
+uint8_t c_ret_u8() {
+    return 0xff;
+}
+uint16_t c_ret_u16() {
+    return 0xffff;
+}
+uint32_t c_ret_u32() {
+    return 0xffffffff;
+}
+uint64_t c_ret_u64() {
+    return 0xffffffffffffffff;
+}
+int8_t c_ret_i8() {
+    return -1;
+}
+int16_t c_ret_i16() {
+    return -1;
+}
+int32_t c_ret_i32() {
+    return -1;
+}
+int64_t c_ret_i64() {
+    return -1;
+}

test/stage1/c_abi/main.zig

@@ -284,3 +284,55 @@ test "C ABI structs of floats as parameter" {
     };
     c_big_struct_floats(v5);
 }
+
+export fn zig_ret_bool() bool {
+    return true;
+}
+export fn zig_ret_u8() u8 {
+    return 0xff;
+}
+export fn zig_ret_u16() u16 {
+    return 0xffff;
+}
+export fn zig_ret_u32() u32 {
+    return 0xffffffff;
+}
+export fn zig_ret_u64() u64 {
+    return 0xffffffffffffffff;
+}
+export fn zig_ret_i8() i8 {
+    return -1;
+}
+export fn zig_ret_i16() i16 {
+    return -1;
+}
+export fn zig_ret_i32() i32 {
+    return -1;
+}
+export fn zig_ret_i64() i64 {
+    return -1;
+}
+
+extern fn c_ret_bool() bool;
+extern fn c_ret_u8() u8;
+extern fn c_ret_u16() u16;
+extern fn c_ret_u32() u32;
+extern fn c_ret_u64() u64;
+extern fn c_ret_i8() i8;
+extern fn c_ret_i16() i16;
+extern fn c_ret_i32() i32;
+extern fn c_ret_i64() i64;
+
+test "C ABI integer return types" {
+    expect(c_ret_bool() == true);
+
+    expect(c_ret_u8() == 0xff);
+    expect(c_ret_u16() == 0xffff);
+    expect(c_ret_u32() == 0xffffffff);
+    expect(c_ret_u64() == 0xffffffffffffffff);
+
+    expect(c_ret_i8() == -1);
+    expect(c_ret_i16() == -1);
+    expect(c_ret_i32() == -1);
+    expect(c_ret_i64() == -1);
+}