cli: Make --got-layout-file override the default GOT layout file loca…

…tion

compiler/plc_driver/src/cli.rs

@@ -5,7 +5,8 @@ use encoding_rs::Encoding;
 use plc_diagnostics::diagnostics::{diagnostics_registry::DiagnosticsConfiguration, Diagnostic};
 use std::{env, ffi::OsStr, num::ParseIntError, path::PathBuf};
 
-use plc::{output::FormatOption, ConfigFormat, DebugLevel, ErrorFormat, Target, Threads};
+use plc::output::FormatOption;
+use plc::{ConfigFormat, DebugLevel, ErrorFormat, Target, Threads, DEFAULT_GOT_LAYOUT_FILE};
 
 pub type ParameterError = clap::Error;
 
@@ -116,9 +117,11 @@ pub struct CompileParameters {
     Save information about the generated custom GOT layout to the given file.
     Format is detected by extension.
     Supported formats : json, toml",
-    parse(try_from_str = validate_config)
+        default_value = DEFAULT_GOT_LAYOUT_FILE,
+        parse(try_from_str = validate_config),
+        requires = "online-change"
     ) ]
-    pub got_layout_file: Option<String>,
+    pub got_layout_file: String,
 
     #[clap(
         name = "optimization",
@@ -407,8 +410,9 @@ impl CompileParameters {
         self.hardware_config.as_deref().and_then(get_config_format)
     }
 
-    pub fn got_layout_format(&self) -> Option<ConfigFormat> {
-        self.got_layout_file.as_deref().and_then(get_config_format)
+    pub fn got_layout_format(&self) -> ConfigFormat {
+        // It is safe to unwrap here, since the provided argument to `--got-online-change` has been checked with `validate_config`
+        get_config_format(&self.got_layout_file).unwrap()
     }
 
     /// Returns the location where the build artifacts should be stored / output

compiler/plc_driver/src/lib.rs

@@ -20,7 +20,7 @@ use cli::{CompileParameters, ParameterError, SubCommands};
 use pipelines::AnnotatedProject;
 use plc::{
     codegen::CodegenContext, linker::LinkerType, output::FormatOption, ConfigFormat, DebugLevel, ErrorFormat,
-    OnlineChange, OptimizationLevel, Target, Threads,
+    OnlineChange, OptimizationLevel, Target, Threads, DEFAULT_GOT_LAYOUT_FILE,
 };
 
 use plc_diagnostics::{diagnostician::Diagnostician, diagnostics::Diagnostic};
@@ -50,8 +50,8 @@ pub struct CompileOptions {
     /// The name of the resulting compiled file
     pub output: String,
     pub output_format: FormatOption,
-    pub got_layout_file: Option<String>,
-    pub got_layout_format: Option<ConfigFormat>,
+    pub got_layout_file: String,
+    pub got_layout_format: ConfigFormat,
     pub optimization: OptimizationLevel,
     pub error_format: ErrorFormat,
     pub debug_level: DebugLevel,
@@ -66,8 +66,8 @@ impl Default for CompileOptions {
             build_location: None,
             output: String::new(),
             output_format: Default::default(),
-            got_layout_file: None,
-            got_layout_format: None,
+            got_layout_file: String::from(DEFAULT_GOT_LAYOUT_FILE),
+            got_layout_format: ConfigFormat::JSON,
             optimization: OptimizationLevel::None,
             error_format: ErrorFormat::None,
             debug_level: DebugLevel::None,

compiler/plc_driver/src/pipelines.rs

@@ -327,7 +327,7 @@ impl<T: SourceContainer + Sync> AnnotatedProject<T> {
             context,
             compile_options.root.as_deref(),
             &unit.file_name,
-            compile_options.got_layout_file.clone().zip(compile_options.got_layout_format),
+            (compile_options.got_layout_file.clone(), compile_options.got_layout_format),
             compile_options.optimization,
             compile_options.debug_level,
             compile_options.online_change,

src/codegen.rs

@@ -78,7 +78,7 @@ pub struct CodeGen<'ink> {
     /// Whether we are generating a hot-reloadable binary or not
     pub online_change: OnlineChange,
 
-    pub got_layout_file: Option<(String, ConfigFormat)>,
+    pub got_layout_file: (String, ConfigFormat),
 
     pub module_location: String,
 }
@@ -97,7 +97,7 @@ impl<'ink> CodeGen<'ink> {
         context: &'ink CodegenContext,
         root: Option<&Path>,
         module_location: &str,
-        got_layout_file: Option<(String, ConfigFormat)>,
+        got_layout_file: (String, ConfigFormat),
         optimization_level: OptimizationLevel,
         debug_level: DebugLevel,
         online_change: OnlineChange,
@@ -135,8 +135,16 @@ impl<'ink> CodeGen<'ink> {
         )?;
         index.merge(llvm_type_index);
 
-        let mut variable_generator =
-            VariableGenerator::new(&self.module, &llvm, global_index, annotations, &index, &mut self.debug);
+        let mut variable_generator = VariableGenerator::new(
+            &self.module,
+            &llvm,
+            global_index,
+            annotations,
+            &index,
+            &mut self.debug,
+            self.got_layout_file.clone(),
+            self.online_change,
+        );
 
         //Generate global variables
         let llvm_gv_index =

src/codegen/generators/variable_generator.rs

@@ -5,6 +5,10 @@ use crate::{
     codegen::{debug::Debug, llvm_index::LlvmTypedIndex, llvm_typesystem::cast_if_needed},
     index::{get_initializer_name, Index, PouIndexEntry, VariableIndexEntry},
     resolver::{AnnotationMap, AstAnnotations, Dependency},
+<<<<<<< HEAD
+=======
+    ConfigFormat, OnlineChange,
+>>>>>>> daa7fadae3 (cli: Make --got-layout-file override the default GOT layout file location)
 };
 use inkwell::{module::Module, values::GlobalValue};
 use plc_ast::ast::LinkageType;
@@ -27,6 +31,11 @@ pub struct VariableGenerator<'ctx, 'b> {
     annotations: &'b AstAnnotations,
     types_index: &'b LlvmTypedIndex<'ctx>,
     debug: &'b mut DebugBuilderEnum<'ctx>,
+<<<<<<< HEAD
+=======
+    got_layout_file: (String, ConfigFormat),
+    online_change: OnlineChange,
+>>>>>>> daa7fadae3 (cli: Make --got-layout-file override the default GOT layout file location)
 }
 
 impl<'ctx, 'b> VariableGenerator<'ctx, 'b> {
@@ -37,8 +46,24 @@ impl<'ctx, 'b> VariableGenerator<'ctx, 'b> {
         annotations: &'b AstAnnotations,
         types_index: &'b LlvmTypedIndex<'ctx>,
         debug: &'b mut DebugBuilderEnum<'ctx>,
+<<<<<<< HEAD
     ) -> Self {
         VariableGenerator { module, llvm, global_index, annotations, types_index, debug }
+=======
+        got_layout_file: (String, ConfigFormat),
+        online_change: OnlineChange,
+    ) -> Self {
+        VariableGenerator {
+            module,
+            llvm,
+            global_index,
+            annotations,
+            types_index,
+            debug,
+            got_layout_file,
+            online_change,
+        }
+>>>>>>> daa7fadae3 (cli: Make --got-layout-file override the default GOT layout file location)
     }
 
     pub fn generate_global_variables(
@@ -100,6 +125,51 @@ impl<'ctx, 'b> VariableGenerator<'ctx, 'b> {
             );
         }
 
+<<<<<<< HEAD
+=======
+        if self.online_change == OnlineChange::Enabled {
+            let (location, format) = &self.got_layout_file;
+
+            let got_entries = read_got_layout(location.as_str(), *format)?;
+            let mut new_globals = Vec::new();
+            let mut new_got_entries = HashMap::new();
+            let mut new_got = HashMap::new();
+
+            for (name, _) in &globals {
+                if let Some(idx) = got_entries.get(&name.to_string()) {
+                    new_got_entries.insert(name.to_string(), *idx);
+                    new_got.insert(*idx, name.to_string());
+                } else {
+                    new_globals.push(name.to_string());
+                }
+            }
+
+            // Put any globals that weren't there last time in any free space in the GOT.
+            let mut idx: u64 = 0;
+            for name in &new_globals {
+                while new_got.contains_key(&idx) {
+                    idx += 1;
+                }
+                new_got_entries.insert(name.to_string(), idx);
+                new_got.insert(idx, name.to_string());
+            }
+
+            // Now we can write new_got_entries back out to a file.
+            write_got_layout(new_got_entries, location.as_str(), *format)?;
+
+            // Construct our GOT as a new global array. We initialise this array in the loader code.
+            let got_size = new_got.keys().max().map_or(0, |m| *m + 1);
+            let _got = self.llvm.create_global_variable(
+                self.module,
+                "__custom_got",
+                BasicTypeEnum::ArrayType(Llvm::get_array_type(
+                    BasicTypeEnum::PointerType(self.llvm.context.i8_type().ptr_type(0.into())),
+                    got_size.try_into().expect("the computed custom GOT size is too large"),
+                )),
+            );
+        }
+
+>>>>>>> daa7fadae3 (cli: Make --got-layout-file override the default GOT layout file location)
         Ok(index)
     }
 

src/lib.rs

@@ -143,6 +143,8 @@ impl FromStr for ConfigFormat {
     }
 }
 
+pub const DEFAULT_GOT_LAYOUT_FILE: &str = "online_change_got.json";
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, ArgEnum, Serialize, Deserialize, Default)]
 pub enum ErrorFormat {
     #[default]