Add DWARF debugging information to all artifacts by default (#422)

* Add DWARF debugging information to all artifacts by default

This commit adds DWARF debugging information with the `-g` compiler flag
to all WASI artifacts for wasi-sdk. The LLVM build itself does not have
debugging information, only the sysroot artifacts. This is intended to
assist with debugging. The main downside to this is binary size of
generated artifacts will, by default, be larger. Stripping debug
information from an artifact though involves removing custom sections
which is generally pretty easy to do through wasm tooling.

* Pass extra cflags to wasi-libc

* Fix tests from previous commit

* Update some expected error messages and remove some files with
  duplicate error messages that are no longer needed.
* Remove undefined behavior in `stat.c` where padding bytes were being
  compared.

Author: alexcrichton

Makefile

@@ -50,6 +50,11 @@ CLANG_VERSION=$(shell $(VERSION_SCRIPT) llvm-major --llvm-dir=$(LLVM_PROJ_DIR))
 VERSION:=$(shell $(VERSION_SCRIPT))
 DEBUG_PREFIX_MAP=-fdebug-prefix-map=$(ROOT_DIR)=wasisdk://v$(VERSION)
 
+# Generate debuginfo by default for wasi-sdk since it's easily strippable and
+# otherwise quite useful for debugging.
+WASI_SDK_CFLAGS := $(DEBUG_PREFIX_MAP) -g
+WASI_SDK_CXXFLAGS := $(WASI_SDK_CFLAGS)
+
 default: build
 	@echo "Use -fdebug-prefix-map=$(ROOT_DIR)=wasisdk://v$(VERSION)"
 
@@ -138,6 +143,7 @@ WASI_LIBC_MAKEFLAGS = \
 	AR=$(BUILD_PREFIX)/bin/llvm-ar \
 	NM=$(BUILD_PREFIX)/bin/llvm-nm \
 	SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
+	EXTRA_CFLAGS="$(WASI_SDK_CFLAGS)" \
 	TARGET_TRIPLE=$(1)
 
 build/wasi-libc.BUILT: build/compiler-rt.BUILT build/wasm-component-ld.BUILT
@@ -166,7 +172,7 @@ build/compiler-rt.BUILT: build/llvm.BUILT
 		-DCOMPILER_RT_ENABLE_IOS=OFF \
 		-DCOMPILER_RT_DEFAULT_TARGET_ONLY=On \
 		-DWASI_SDK_PREFIX=$(BUILD_PREFIX) \
-		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP)" \
+		-DCMAKE_C_FLAGS="$(WASI_SDK_CFLAGS)" \
 		-DLLVM_CONFIG_PATH=$(ROOT_DIR)/build/llvm/bin/llvm-config \
 		-DCOMPILER_RT_OS_DIR=wasi \
 		-DCMAKE_INSTALL_PREFIX=$(PREFIX)/lib/clang/$(CLANG_VERSION)/ \
@@ -225,8 +231,8 @@ LIBCXX_CMAKE_FLAGS = \
     -DUNIX:BOOL=ON \
     --debug-trycompile \
     -DCMAKE_SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
-    -DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP) $(EXTRA_CFLAGS) $(4) --target=$(3)" \
-    -DCMAKE_CXX_FLAGS="$(DEBUG_PREFIX_MAP) $(EXTRA_CXXFLAGS) $(4) --target=$(3)" \
+    -DCMAKE_C_FLAGS="$(WASI_SDK_CFLAGS) $(EXTRA_CFLAGS) $(4) --target=$(3)" \
+    -DCMAKE_CXX_FLAGS="$(WASI_SDK_CXXFLAGS) $(EXTRA_CXXFLAGS) $(4) --target=$(3)" \
     -DLIBCXX_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/$(3) \
     -DLIBCXXABI_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/$(3) \
     -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \

src/wasi-libc

@@ -1,6 +1,7 @@
 Error: failed to run main module `abort.c.---.wasm`
 
 Caused by:
-    0: failed to invoke command default
+    0: failed to invoke ---
     1: error while executing at wasm backtrace:
+       note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
     2: wasm trap: wasm `unreachable` instruction executed

tests/general/abort.c.stderr.expected

@@ -3,4 +3,5 @@ set -euo pipefail
 
 cat \
     | sed -e 's/main module `abort\.c\.[^`]*\.wasm`/main module `abort.c.---.wasm`/' \
+    | sed -e 's/failed to invoke.*/failed to invoke ---/' \
     | sed -E '/0x[[:xdigit:]]+/d'

tests/general/abort.c.stderr.expected.filter

@@ -2,6 +2,7 @@ Assertion failed: false (assert-fail.c: main: 5)
 Error: failed to run main module `assert-fail.c.---.wasm`
 
 Caused by:
-    0: failed to invoke command default
+    0: failed to invoke ---
     1: error while executing at wasm backtrace:
+       note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
     2: wasm trap: wasm `unreachable` instruction executed

tests/general/abort.c.wasm32-wasi-preview2.stderr.expected

@@ -3,4 +3,5 @@ set -euo pipefail
 
 cat \
     | sed -e 's/main module `assert-fail\.c\.[^`]*\.wasm`/main module `assert-fail.c.---.wasm`/' \
+    | sed -e 's/failed to invoke.*/failed to invoke ---/' \
     | sed -E '/0x[[:xdigit:]]+/d'