support --target-arch wasm32 (#1094)

bnoordhuis · andrewrk · commit d464b2532200 · 2018-06-09T22:39:22.000-04:00
Add wasm32 support to the build-obj, build-exe and build-lib commands of the stage 1 compiler. Wasm64 should work transparently once it's supported in upstream LLVM. To export a function: // lib.zig - for exposition, not necessary for this example pub use @import("add.zig"); // add.zig export fn add(a: i32, b: i32) i32 { return a + b; } To import a function: // cube.zig extern fn square(x: i32) i32; export fn cube(x: i32) i32 { return x * square(x); }
diff --git a/build.zig b/build.zig
@@ -63,6 +63,7 @@ pub fn build(b: *Builder) !void {
             exe.addObjectFile(lib);
         }
     } else {
+        addCppLib(b, exe, cmake_binary_dir, "embedded_lld_wasm");
         addCppLib(b, exe, cmake_binary_dir, "embedded_lld_elf");
         addCppLib(b, exe, cmake_binary_dir, "embedded_lld_coff");
         addCppLib(b, exe, cmake_binary_dir, "embedded_lld_lib");
diff --git a/src/link.cpp b/src/link.cpp
@@ -391,6 +391,19 @@ static void construct_linker_job_elf(LinkJob *lj) {
     }
 }
 
+static void construct_linker_job_wasm(LinkJob *lj) {
+    CodeGen *g = lj->codegen;
+
+    lj->args.append("--relocatable");  // So lld doesn't look for _start.
+    lj->args.append("-o");
+    lj->args.append(buf_ptr(&lj->out_file));
+
+    // .o files
+    for (size_t i = 0; i < g->link_objects.length; i += 1) {
+        lj->args.append((const char *)buf_ptr(g->link_objects.at(i)));
+    }
+}
+
 //static bool is_target_cyg_mingw(const ZigTarget *target) {
 //    return (target->os == ZigLLVM_Win32 && target->env_type == ZigLLVM_Cygnus) ||
 //        (target->os == ZigLLVM_Win32 && target->env_type == ZigLLVM_GNU);
@@ -924,7 +937,7 @@ static void construct_linker_job(LinkJob *lj) {
         case ZigLLVM_MachO:
             return construct_linker_job_macho(lj);
         case ZigLLVM_Wasm:
-            zig_panic("TODO link wasm");
+            return construct_linker_job_wasm(lj);
     }
 }
 
diff --git a/src/target.cpp b/src/target.cpp
@@ -597,12 +597,15 @@ void resolve_target_object_format(ZigTarget *target) {
         case ZigLLVM_tce:
         case ZigLLVM_tcele:
         case ZigLLVM_thumbeb:
-        case ZigLLVM_wasm32:
-        case ZigLLVM_wasm64:
         case ZigLLVM_xcore:
             target->oformat= ZigLLVM_ELF;
             return;
 
+        case ZigLLVM_wasm32:
+        case ZigLLVM_wasm64:
+            target->oformat = ZigLLVM_Wasm;
+            return;
+
         case ZigLLVM_ppc:
         case ZigLLVM_ppc64:
             if (is_os_darwin(target)) {
diff --git a/src/zig_llvm.cpp b/src/zig_llvm.cpp
@@ -838,7 +838,7 @@ bool ZigLLDLink(ZigLLVM_ObjectFormatType oformat, const char **args, size_t arg_
             return lld::mach_o::link(array_ref_args, diag);
 
         case ZigLLVM_Wasm:
-            assert(false); // TODO ZigLLDLink for Wasm
+            return lld::wasm::link(array_ref_args, false, diag);
     }
     assert(false); // unreachable
     abort();

Original file line number	Diff line number	Diff line change
`@@ -63,6 +63,7 @@ pub fn build(b: *Builder) !void {`
`63`	`63`	`exe.addObjectFile(lib);`
`64`	`64`	`}`
`65`	`65`	`} else {`
	`66`	`+ addCppLib(b, exe, cmake_binary_dir, "embedded_lld_wasm");`
`66`	`67`	`addCppLib(b, exe, cmake_binary_dir, "embedded_lld_elf");`
`67`	`68`	`addCppLib(b, exe, cmake_binary_dir, "embedded_lld_coff");`
`68`	`69`	`addCppLib(b, exe, cmake_binary_dir, "embedded_lld_lib");`
Original file line number	Diff line number	Diff line change
`@@ -838,7 +838,7 @@ bool ZigLLDLink(ZigLLVM_ObjectFormatType oformat, const char **args, size_t arg_`
`838`	`838`	`return lld::mach_o::link(array_ref_args, diag);`
`839`	`839`
`840`	`840`	`case ZigLLVM_Wasm:`
`841`		`- assert(false); // TODO ZigLLDLink for Wasm`
	`841`	`+ return lld::wasm::link(array_ref_args, false, diag);`
`842`	`842`	`}`
`843`	`843`	`assert(false); // unreachable`
`844`	`844`	`abort();`