Auto merge of rust-lang#113559 - matthiaskrgr:rollup-jrqyctc, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#113386 (style-guide: Expand example of combinable expressions to include arrays)
 - rust-lang#113523 (Reuse LLVMConstInBoundsGEP2)
 - rust-lang#113528 (Dynamically size sigaltstk in rustc)
 - rust-lang#113543 (Remove `rustc_llvm` from llvm-stamp nags)
 - rust-lang#113548 (Update books)
 - rust-lang#113551 (bootstrap: Don't print "Skipping" twice)
 - rust-lang#113556 (Don't use serde-derive in the rls shim)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Cargo.lock

@@ -3021,7 +3021,6 @@ dependencies = [
 name = "rls"
 version = "2.0.0"
 dependencies = [
- "serde",
  "serde_json",
 ]
 

compiler/rustc_codegen_llvm/src/common.rs

@@ -290,7 +290,7 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                     }
                 };
                 let llval = unsafe {
-                    llvm::LLVMRustConstInBoundsGEP2(
+                    llvm::LLVMConstInBoundsGEP2(
                         self.type_i8(),
                         self.const_bitcast(base_addr, self.type_i8p_ext(base_addr_space)),
                         &self.const_usize(offset.bytes()),
@@ -320,7 +320,7 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
     fn const_ptr_byte_offset(&self, base_addr: Self::Value, offset: abi::Size) -> Self::Value {
         unsafe {
-            llvm::LLVMRustConstInBoundsGEP2(
+            llvm::LLVMConstInBoundsGEP2(
                 self.type_i8(),
                 self.const_bitcast(base_addr, self.type_i8p()),
                 &self.const_usize(offset.bytes()),

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1155,7 +1155,7 @@ extern "C" {
     pub fn LLVMConstVector(ScalarConstantVals: *const &Value, Size: c_uint) -> &Value;
 
     // Constant expressions
-    pub fn LLVMRustConstInBoundsGEP2<'a>(
+    pub fn LLVMConstInBoundsGEP2<'a>(
         ty: &'a Type,
         ConstantVal: &'a Value,
         ConstantIndices: *const &'a Value,

compiler/rustc_driver_impl/src/lib.rs

@@ -1453,13 +1453,13 @@ mod signal_handler {
     /// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
     /// process, print a stack trace and then exit.
     pub(super) fn install() {
+        use std::alloc::{alloc, Layout};
+
         unsafe {
-            const ALT_STACK_SIZE: usize = libc::MINSIGSTKSZ + 64 * 1024;
+            let alt_stack_size: usize = min_sigstack_size() + 64 * 1024;
             let mut alt_stack: libc::stack_t = std::mem::zeroed();
-            alt_stack.ss_sp =
-                std::alloc::alloc(std::alloc::Layout::from_size_align(ALT_STACK_SIZE, 1).unwrap())
-                    as *mut libc::c_void;
-            alt_stack.ss_size = ALT_STACK_SIZE;
+            alt_stack.ss_sp = alloc(Layout::from_size_align(alt_stack_size, 1).unwrap()).cast();
+            alt_stack.ss_size = alt_stack_size;
             libc::sigaltstack(&alt_stack, std::ptr::null_mut());
 
             let mut sa: libc::sigaction = std::mem::zeroed();
@@ -1469,6 +1469,23 @@ mod signal_handler {
             libc::sigaction(libc::SIGSEGV, &sa, std::ptr::null_mut());
         }
     }
+
+    /// Modern kernels on modern hardware can have dynamic signal stack sizes.
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    fn min_sigstack_size() -> usize {
+        const AT_MINSIGSTKSZ: core::ffi::c_ulong = 51;
+        let dynamic_sigstksz = unsafe { libc::getauxval(AT_MINSIGSTKSZ) };
+        // If getauxval couldn't find the entry, it returns 0,
+        // so take the higher of the "constant" and auxval.
+        // This transparently supports older kernels which don't provide AT_MINSIGSTKSZ
+        libc::MINSIGSTKSZ.max(dynamic_sigstksz as _)
+    }
+
+    /// Not all OS support hardware where this is needed.
+    #[cfg(not(any(target_os = "linux", target_os = "android")))]
+    fn min_sigstack_size() -> usize {
+        libc::MINSIGSTKSZ
+    }
 }
 
 #[cfg(not(all(unix, any(target_env = "gnu", target_os = "macos"))))]

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1616,17 +1616,6 @@ extern "C" void LLVMRustSetLinkage(LLVMValueRef V,
   LLVMSetLinkage(V, fromRust(RustLinkage));
 }
 
-// FIXME: replace with LLVMConstInBoundsGEP2 when bumped minimal version to llvm-14
-extern "C" LLVMValueRef LLVMRustConstInBoundsGEP2(LLVMTypeRef Ty,
-                                                  LLVMValueRef ConstantVal,
-                                                  LLVMValueRef *ConstantIndices,
-                                                  unsigned NumIndices) {
-  ArrayRef<Constant *> IdxList(unwrap<Constant>(ConstantIndices, NumIndices),
-                               NumIndices);
-  Constant *Val = unwrap<Constant>(ConstantVal);
-  return wrap(ConstantExpr::getInBoundsGetElementPtr(unwrap(Ty), Val, IdxList));
-}
-
 extern "C" bool LLVMRustConstIntGetZExtValue(LLVMValueRef CV, uint64_t *value) {
     auto C = unwrap<llvm::ConstantInt>(CV);
     if (C->getBitWidth() > 64)

src/bootstrap/builder.rs

@@ -13,7 +13,7 @@ use std::process::Command;
 use std::time::{Duration, Instant};
 
 use crate::cache::{Cache, Interned, INTERNER};
-use crate::config::{SplitDebuginfo, TargetSelection};
+use crate::config::{DryRun, SplitDebuginfo, TargetSelection};
 use crate::doc;
 use crate::flags::{Color, Subcommand};
 use crate::install;
@@ -281,11 +281,15 @@ impl StepDescription {
 
     fn is_excluded(&self, builder: &Builder<'_>, pathset: &PathSet) -> bool {
         if builder.config.exclude.iter().any(|e| pathset.has(&e, builder.kind)) {
-            println!("Skipping {:?} because it is excluded", pathset);
+            if !matches!(builder.config.dry_run, DryRun::SelfCheck) {
+                println!("Skipping {:?} because it is excluded", pathset);
+            }
             return true;
         }
 
-        if !builder.config.exclude.is_empty() {
+        if !builder.config.exclude.is_empty()
+            && !matches!(builder.config.dry_run, DryRun::SelfCheck)
+        {
             builder.verbose(&format!(
                 "{:?} not skipped for {:?} -- not in {:?}",
                 pathset, self.name, builder.config.exclude