Commit 4d01385e14

Andrew Kelley <andrew@ziglang.org>
2020-07-07 05:48:20
fix liveness analysis and not correctly propagating link errors
We still flush the ELF file even when there are compile errors.
1 parent 12737c9
Changed files (4)
src-self-hosted/link.zig
@@ -369,7 +369,7 @@ pub const ElfFile = struct {
             const file_size = self.options.program_code_size_hint;
             const p_align = 0x1000;
             const off = self.findFreeSpace(file_size, p_align);
-            //std.log.debug(.link, "found PT_LOAD free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
+            std.log.debug(.link, "found PT_LOAD free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
             try self.program_headers.append(self.allocator, .{
                 .p_type = elf.PT_LOAD,
                 .p_offset = off,
@@ -390,7 +390,7 @@ pub const ElfFile = struct {
             // page align.
             const p_align = 0x1000;
             const off = self.findFreeSpace(file_size, p_align);
-            //std.log.debug(.link, "found PT_LOAD free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
+            std.log.debug(.link, "found PT_LOAD free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
             // TODO instead of hard coding the vaddr, make a function to find a vaddr to put things at.
             // we'll need to re-use that function anyway, in case the GOT grows and overlaps something
             // else in virtual memory.
@@ -412,7 +412,7 @@ pub const ElfFile = struct {
             assert(self.shstrtab.items.len == 0);
             try self.shstrtab.append(self.allocator, 0); // need a 0 at position 0
             const off = self.findFreeSpace(self.shstrtab.items.len, 1);
-            //std.log.debug(.link, "found shstrtab free space 0x{x} to 0x{x}\n", .{ off, off + self.shstrtab.items.len });
+            std.log.debug(.link, "found shstrtab free space 0x{x} to 0x{x}\n", .{ off, off + self.shstrtab.items.len });
             try self.sections.append(self.allocator, .{
                 .sh_name = try self.makeString(".shstrtab"),
                 .sh_type = elf.SHT_STRTAB,
@@ -470,7 +470,7 @@ pub const ElfFile = struct {
             const each_size: u64 = if (small_ptr) @sizeOf(elf.Elf32_Sym) else @sizeOf(elf.Elf64_Sym);
             const file_size = self.options.symbol_count_hint * each_size;
             const off = self.findFreeSpace(file_size, min_align);
-            //std.log.debug(.link, "found symtab free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
+            std.log.debug(.link, "found symtab free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
 
             try self.sections.append(self.allocator, .{
                 .sh_name = try self.makeString(".symtab"),
@@ -586,7 +586,7 @@ pub const ElfFile = struct {
                     shstrtab_sect.sh_offset = self.findFreeSpace(needed_size, 1);
                 }
                 shstrtab_sect.sh_size = needed_size;
-                //std.log.debug(.link, "shstrtab start=0x{x} end=0x{x}\n", .{ shstrtab_sect.sh_offset, shstrtab_sect.sh_offset + needed_size });
+                std.log.debug(.link, "shstrtab start=0x{x} end=0x{x}\n", .{ shstrtab_sect.sh_offset, shstrtab_sect.sh_offset + needed_size });
 
                 try self.file.?.pwriteAll(self.shstrtab.items, shstrtab_sect.sh_offset);
                 if (!self.shdr_table_dirty) {
@@ -632,7 +632,7 @@ pub const ElfFile = struct {
 
                     for (buf) |*shdr, i| {
                         shdr.* = self.sections.items[i];
-                        //std.log.debug(.link, "writing section {}\n", .{shdr.*});
+                        std.log.debug(.link, "writing section {}\n", .{shdr.*});
                         if (foreign_endian) {
                             bswapAllFields(elf.Elf64_Shdr, shdr);
                         }
@@ -643,6 +643,7 @@ pub const ElfFile = struct {
             self.shdr_table_dirty = false;
         }
         if (self.entry_addr == null and self.options.output_mode == .Exe) {
+            std.log.debug(.link, "no_entry_point_found = true\n", .{});
             self.error_flags.no_entry_point_found = true;
         } else {
             self.error_flags.no_entry_point_found = false;
@@ -956,10 +957,10 @@ pub const ElfFile = struct {
         try self.offset_table_free_list.ensureCapacity(self.allocator, self.local_symbols.items.len);
 
         if (self.local_symbol_free_list.popOrNull()) |i| {
-            //std.log.debug(.link, "reusing symbol index {} for {}\n", .{i, decl.name});
+            std.log.debug(.link, "reusing symbol index {} for {}\n", .{i, decl.name});
             decl.link.local_sym_index = i;
         } else {
-            //std.log.debug(.link, "allocating symbol index {} for {}\n", .{self.local_symbols.items.len, decl.name});
+            std.log.debug(.link, "allocating symbol index {} for {}\n", .{self.local_symbols.items.len, decl.name});
             decl.link.local_sym_index = @intCast(u32, self.local_symbols.items.len);
             _ = self.local_symbols.addOneAssumeCapacity();
         }
@@ -1027,11 +1028,11 @@ pub const ElfFile = struct {
                 !mem.isAlignedGeneric(u64, local_sym.st_value, required_alignment);
             if (need_realloc) {
                 const vaddr = try self.growTextBlock(&decl.link, code.len, required_alignment);
-                //std.log.debug(.link, "growing {} from 0x{x} to 0x{x}\n", .{ decl.name, local_sym.st_value, vaddr });
+                std.log.debug(.link, "growing {} from 0x{x} to 0x{x}\n", .{ decl.name, local_sym.st_value, vaddr });
                 if (vaddr != local_sym.st_value) {
                     local_sym.st_value = vaddr;
 
-                    //std.log.debug(.link, "  (writing new offset table entry)\n", .{});
+                    std.log.debug(.link, "  (writing new offset table entry)\n", .{});
                     self.offset_table.items[decl.link.offset_table_index] = vaddr;
                     try self.writeOffsetTableEntry(decl.link.offset_table_index);
                 }
@@ -1049,7 +1050,7 @@ pub const ElfFile = struct {
             const decl_name = mem.spanZ(decl.name);
             const name_str_index = try self.makeString(decl_name);
             const vaddr = try self.allocateTextBlock(&decl.link, code.len, required_alignment);
-            //std.log.debug(.link, "allocated text block for {} at 0x{x}\n", .{ decl_name, vaddr });
+            std.log.debug(.link, "allocated text block for {} at 0x{x}\n", .{ decl_name, vaddr });
             errdefer self.freeTextBlock(&decl.link);
 
             local_sym.* = .{
src-self-hosted/liveness.zig
@@ -25,22 +25,25 @@ fn analyzeWithTable(arena: *std.mem.Allocator, table: *std.AutoHashMap(*ir.Inst,
     while (i != 0) {
         i -= 1;
         const base = body.instructions[i];
+        try analyzeInstGeneric(arena, table, base);
+    }
+}
 
-        // Obtain the corresponding instruction type based on the tag type.
-        inline for (std.meta.declarations(ir.Inst)) |decl| {
-            switch (decl.data) {
-                .Type => |T| {
-                    if (@hasDecl(T, "base_tag")) {
-                        if (T.base_tag == base.tag) {
-                            return analyzeInst(arena, table, T, @fieldParentPtr(T, "base", base));
-                        }
+fn analyzeInstGeneric(arena: *std.mem.Allocator, table: *std.AutoHashMap(*ir.Inst, void), base: *ir.Inst) error{OutOfMemory}!void {
+    // Obtain the corresponding instruction type based on the tag type.
+    inline for (std.meta.declarations(ir.Inst)) |decl| {
+        switch (decl.data) {
+            .Type => |T| {
+                if (@hasDecl(T, "base_tag")) {
+                    if (T.base_tag == base.tag) {
+                        return analyzeInst(arena, table, T, @fieldParentPtr(T, "base", base));
                     }
-                },
-                else => continue,
-            }
+                }
+            },
+            else => {},
         }
-        unreachable;
     }
+    unreachable;
 }
 
 fn analyzeInst(arena: *std.mem.Allocator, table: *std.AutoHashMap(*ir.Inst, void), comptime T: type, inst: *T) error{OutOfMemory}!void {
@@ -131,4 +134,6 @@ fn analyzeInst(arena: *std.mem.Allocator, table: *std.AutoHashMap(*ir.Inst, void
             arg_index += 1;
         }
     }
+
+    std.log.debug(.liveness, "analyze {}: 0b{b}\n", .{inst.base.tag, inst.base.deaths});
 }
src-self-hosted/main.zig
@@ -50,7 +50,10 @@ pub fn log(
     const scope_prefix = "(" ++ switch (scope) {
         // Uncomment to hide logs
         //.compiler,
-        .link => return,
+        .module,
+        .liveness,
+        .link,
+        => return,
 
         else => @tagName(scope),
     } ++ "): ";
src-self-hosted/Module.zig
@@ -867,15 +867,16 @@ pub fn update(self: *Module) !void {
         try self.deleteDecl(decl);
     }
 
+    // This is needed before reading the error flags.
+    try self.bin_file.flush();
+
     self.link_error_flags = self.bin_file.error_flags;
+    std.log.debug(.module, "link_error_flags: {}\n", .{self.link_error_flags});
 
     // If there are any errors, we anticipate the source files being loaded
     // to report error messages. Otherwise we unload all source files to save memory.
-    if (self.totalErrorCount() == 0) {
-        if (!self.keep_source_files_loaded) {
-            self.root_scope.unload(self.gpa);
-        }
-        try self.bin_file.flush();
+    if (self.totalErrorCount() == 0 and !self.keep_source_files_loaded) {
+        self.root_scope.unload(self.gpa);
     }
 }
 
@@ -975,6 +976,7 @@ pub fn performAllTheWork(self: *Module) error{OutOfMemory}!void {
                     // lifetime annotations in the ZIR.
                     var decl_arena = decl.typed_value.most_recent.arena.?.promote(self.gpa);
                     defer decl.typed_value.most_recent.arena.?.* = decl_arena.state;
+                    std.log.debug(.module, "analyze liveness of {}\n", .{decl.name});
                     try liveness.analyze(self.gpa, &decl_arena.allocator, payload.func.analysis.success);
                 }