Support building glibc for riscv32/riscv64

lib/libc/include/riscv64-linux-gnu/gnu/lib-names-lp64.h → lib/libc/include/riscv32-linux-gnu/gnu/lib-names-ilp32d.h

@@ -1,10 +1,10 @@
 /* This file is automatically generated.  */
 #ifndef __GNU_LIB_NAMES_H
-# error "Never use <gnu/lib-names-lp64.h> directly; include <gnu/lib-names.h> instead."
+# error "Never use <gnu/lib-names-ilp32d.h> directly; include <gnu/lib-names.h> instead."
 #endif
 
-#define LD_LINUX_RISCV64_LP64_SO        "ld-linux-riscv64-lp64.so.1"
-#define LD_SO                           "ld-linux-riscv64-lp64.so.1"
+#define LD_LINUX_RISCV32_ILP32D_SO      "ld-linux-riscv32-ilp32d.so.1"
+#define LD_SO                           "ld-linux-riscv32-ilp32d.so.1"
 #define LIBANL_SO                       "libanl.so.1"
 #define LIBBROKENLOCALE_SO              "libBrokenLocale.so.1"
 #define LIBC_MALLOC_DEBUG_SO            "libc_malloc_debug.so.0"
@@ -24,4 +24,4 @@
 #define LIBRESOLV_SO                    "libresolv.so.2"
 #define LIBRT_SO                        "librt.so.1"
 #define LIBTHREAD_DB_SO                 "libthread_db.so.1"
-#define LIBUTIL_SO                      "libutil.so.1"
+#define LIBUTIL_SO                      "libutil.so.1"

lib/libc/include/riscv32-linux-gnuilp32/gnu/stubs-ilp32.h → lib/libc/include/riscv32-linux-gnu/gnu/stubs-ilp32d.h

@@ -14,25 +14,11 @@
 #define __stub___compat_uselib
 #define __stub_chflags
 #define __stub_fchflags
-#define __stub_feclearexcept
 #define __stub_fedisableexcept
 #define __stub_feenableexcept
-#define __stub_fegetenv
 #define __stub_fegetexcept
-#define __stub_fegetexceptflag
-#define __stub_fegetmode
-#define __stub_fegetround
-#define __stub_feholdexcept
-#define __stub_feraiseexcept
-#define __stub_fesetenv
-#define __stub_fesetexcept
-#define __stub_fesetexceptflag
-#define __stub_fesetmode
-#define __stub_fesetround
-#define __stub_fetestexcept
-#define __stub_feupdateenv
 #define __stub_gtty
 #define __stub_revoke
 #define __stub_setlogin
 #define __stub_sigreturn
-#define __stub_stty
+#define __stub_stty

lib/libc/include/riscv32-linux-gnuilp32/gnu/lib-names-ilp32.h → lib/libc/include/riscv64-linux-gnu/gnu/lib-names-lp64d.h

@@ -1,10 +1,10 @@
 /* This file is automatically generated.  */
 #ifndef __GNU_LIB_NAMES_H
-# error "Never use <gnu/lib-names-ilp32.h> directly; include <gnu/lib-names.h> instead."
+# error "Never use <gnu/lib-names-lp64d.h> directly; include <gnu/lib-names.h> instead."
 #endif
 
-#define LD_LINUX_RISCV32_ILP32_SO       "ld-linux-riscv32-ilp32.so.1"
-#define LD_SO                           "ld-linux-riscv32-ilp32.so.1"
+#define LD_LINUX_RISCV64_LP64D_SO       "ld-linux-riscv64-lp64d.so.1"
+#define LD_SO                           "ld-linux-riscv64-lp64d.so.1"
 #define LIBANL_SO                       "libanl.so.1"
 #define LIBBROKENLOCALE_SO              "libBrokenLocale.so.1"
 #define LIBC_MALLOC_DEBUG_SO            "libc_malloc_debug.so.0"
@@ -24,4 +24,4 @@
 #define LIBRESOLV_SO                    "libresolv.so.2"
 #define LIBRT_SO                        "librt.so.1"
 #define LIBTHREAD_DB_SO                 "libthread_db.so.1"
-#define LIBUTIL_SO                      "libutil.so.1"
+#define LIBUTIL_SO                      "libutil.so.1"

lib/libc/include/riscv64-linux-gnu/gnu/stubs-lp64.h → lib/libc/include/riscv64-linux-gnu/gnu/stubs-lp64d.h

@@ -14,25 +14,11 @@
 #define __stub___compat_uselib
 #define __stub_chflags
 #define __stub_fchflags
-#define __stub_feclearexcept
 #define __stub_fedisableexcept
 #define __stub_feenableexcept
-#define __stub_fegetenv
 #define __stub_fegetexcept
-#define __stub_fegetexceptflag
-#define __stub_fegetmode
-#define __stub_fegetround
-#define __stub_feholdexcept
-#define __stub_feraiseexcept
-#define __stub_fesetenv
-#define __stub_fesetexcept
-#define __stub_fesetexceptflag
-#define __stub_fesetmode
-#define __stub_fesetround
-#define __stub_fetestexcept
-#define __stub_feupdateenv
 #define __stub_gtty
 #define __stub_revoke
 #define __stub_setlogin
 #define __stub_sigreturn
-#define __stub_stty
+#define __stub_stty

lib/std/Target.zig

@@ -483,7 +483,21 @@ pub const Os = struct {
                             .min = .{ .major = 4, .minor = 19, .patch = 0 },
                             .max = .{ .major = 6, .minor = 5, .patch = 7 },
                         },
-                        .glibc = .{ .major = 2, .minor = 28, .patch = 0 },
+                        .glibc = blk: {
+                            const default_min = .{ .major = 2, .minor = 28, .patch = 0 };
+
+                            for (std.zig.target.available_libcs) |libc| {
+                                // We don't know the ABI here. We can get away with not checking it
+                                // for now, but that may not always remain true.
+                                if (libc.os != tag or libc.arch != arch) continue;
+
+                                if (libc.glibc_min) |min| {
+                                    if (min.order(default_min) == .gt) break :blk min;
+                                }
+                            }
+
+                            break :blk default_min;
+                        },
                     },
                 },
 
@@ -1728,8 +1742,8 @@ pub const DynamicLinker = struct {
                     else => "/lib64/ld-linux-x86-64.so.2",
                 }),
 
-                .riscv32 => init("/lib/ld-linux-riscv32-ilp32.so.1"),
-                .riscv64 => init("/lib/ld-linux-riscv64-lp64.so.1"),
+                .riscv32 => init("/lib/ld-linux-riscv32-ilp32d.so.1"),
+                .riscv64 => init("/lib/ld-linux-riscv64-lp64d.so.1"),
 
                 // Architectures in this list have been verified as not having a standard
                 // dynamic linker path.

lib/std/zig/target.zig

@@ -56,7 +56,7 @@ pub const available_libcs = [_]ArchOsAbi{
     .{ .arch = .powerpc, .os = .linux, .abi = .gnueabi },
     .{ .arch = .powerpc, .os = .linux, .abi = .gnueabihf },
     .{ .arch = .powerpc, .os = .linux, .abi = .musl },
-    .{ .arch = .riscv32, .os = .linux, .abi = .gnuilp32, .glibc_min = .{ .major = 2, .minor = 33, .patch = 0 } },
+    .{ .arch = .riscv32, .os = .linux, .abi = .gnu, .glibc_min = .{ .major = 2, .minor = 33, .patch = 0 } },
     .{ .arch = .riscv32, .os = .linux, .abi = .musl },
     .{ .arch = .riscv64, .os = .linux, .abi = .gnu, .glibc_min = .{ .major = 2, .minor = 27, .patch = 0 } },
     .{ .arch = .riscv64, .os = .linux, .abi = .musl },

src/glibc.zig

@@ -164,6 +164,21 @@ pub fn loadMetaData(gpa: Allocator, contents: []const u8) LoadMetaDataError!*ABI
     return abi;
 }
 
+fn useElfInitFini(target: std.Target) bool {
+    // Legacy architectures use _init/_fini.
+    return switch (target.cpu.arch) {
+        .arm, .armeb, .thumb, .thumbeb => true,
+        .aarch64, .aarch64_be => true,
+        .m68k => true,
+        .mips, .mipsel, .mips64, .mips64el => true,
+        .powerpc, .powerpcle, .powerpc64, .powerpc64le => true,
+        .s390x => true,
+        .sparc, .sparc64 => true,
+        .x86, .x86_64 => true,
+        else => false,
+    };
+}
+
 pub const CRTFile = enum {
     crti_o,
     crtn_o,
@@ -359,8 +374,7 @@ pub fn buildCRTFile(comp: *Compilation, crt_file: CRTFile, prog_node: std.Progre
                     "-std=gnu11",
                     "-fgnu89-inline",
                     "-fmerge-all-constants",
-                    // glibc sets this flag but clang does not support it.
-                    // "-frounding-math",
+                    "-frounding-math",
                     "-fno-stack-protector",
                     "-fno-common",
                     "-fmath-errno",
@@ -369,6 +383,10 @@ pub fn buildCRTFile(comp: *Compilation, crt_file: CRTFile, prog_node: std.Progre
                 });
                 try add_include_dirs(comp, arena, &args);
 
+                if (!useElfInitFini(target)) {
+                    try args.append("-DNO_INITFINI");
+                }
+
                 if (target.cpu.arch == .x86) {
                     // This prevents i386/sysdep.h from trying to do some
                     // silly and unnecessary inline asm hack that uses weird

src/main.zig

@@ -3412,6 +3412,14 @@ fn buildOutputType(
                         std.log.info("zig can provide libc for related target {s}-{s}.{d}-{s}", .{
                             @tagName(t.arch), @tagName(t.os), os_ver.major, @tagName(t.abi),
                         });
+                    } else if (t.glibc_min) |glibc_min| {
+                        std.log.info("zig can provide libc for related target {s}-{s}-{s}.{d}.{d}", .{
+                            @tagName(t.arch),
+                            @tagName(t.os),
+                            @tagName(t.abi),
+                            glibc_min.major,
+                            glibc_min.minor,
+                        });
                     } else {
                         std.log.info("zig can provide libc for related target {s}-{s}-{s}", .{
                             @tagName(t.arch), @tagName(t.os), @tagName(t.abi),

src/target.zig

@@ -369,7 +369,6 @@ pub fn addrSpaceCastIsValid(
 
 pub fn llvmMachineAbi(target: std.Target) ?[:0]const u8 {
     const have_float = switch (target.abi) {
-        .gnuilp32 => return "ilp32",
         .gnueabihf, .musleabihf, .eabihf => true,
         else => false,
     };

tools/process_headers.zig

@@ -160,12 +160,12 @@ const glibc_targets = [_]LibCTarget{
         .abi = MultiAbi{ .specific = Abi.gnueabi },
     },
     LibCTarget{
-        .name = "riscv32-linux-gnu-rv32imac-ilp32",
+        .name = "riscv32-linux-gnu-rv32imafdc-ilp32d",
         .arch = MultiArch{ .specific = Arch.riscv32 },
-        .abi = MultiAbi{ .specific = Abi.gnuilp32 },
+        .abi = MultiAbi{ .specific = Abi.gnu },
     },
     LibCTarget{
-        .name = "riscv64-linux-gnu-rv64imac-lp64",
+        .name = "riscv64-linux-gnu-rv64imafdc-lp64d",
         .arch = MultiArch{ .specific = Arch.riscv64 },
         .abi = MultiAbi{ .specific = Abi.gnu },
     },