Add hello-world exercise

.gitignore

@@ -2,3 +2,7 @@
 .DS_Store
 bin/configlet
 bin/configlet.exe
+build/
+**/tests
+**/*.o
+*.pyc

.travis.yml

@@ -1,5 +1,15 @@
-language: bash
+language: c
+
+arch:
+  - arm64
+
+os:
+  - linux
+
+compiler:
+  - gcc
 
 script:
   - bin/fetch-configlet
   - bin/configlet lint --track-id arm64-assembly .
+  - bin/verify-exercises

bin/verify-exercises

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+set -e
+
+run_tests() {
+    local file="${1//-/_}"
+
+    cd "$1"
+
+    sed -i.bak 's#TEST_IGNORE();#// &#' "${file}"_test.c
+    mv example.s "${file}".s
+
+    make clean
+    make
+
+    cd ..
+}
+
+main() {
+    cd "$(dirname "$0")"/..
+
+    rm -rf build
+    cp -r exercises build
+
+    cd build
+
+    if [[ $# -gt 0 ]]; then
+        for exercise in "$@"; do
+            run_tests "${exercise}"
+        done
+    else
+        for exercise in *; do
+            run_tests "${exercise}"
+        done
+    fi
+
+}
+
+main "$@"

config.json

@@ -6,5 +6,17 @@
   "ignore_pattern": "[Ee]xample",
   "solution_pattern": "[Ee]xample",
   "test_pattern": "[Tt]est",
-  "exercises": null
+  "exercises": [
+    {
+      "slug": "hello-world",
+      "uuid": "669a233b-b6c3-4d18-81d8-41b906ad5eb1",
+      "core": true,
+      "auto_approve": true,
+      "unlocked_by": null,
+      "difficulty": 1,
+      "topics": [
+        "strings"
+      ]
+    }
+  ]
 }

exercises/hello-world/Makefile

@@ -0,0 +1,35 @@
+AS = as
+
+CFLAGS = -g -Wall -Wextra -pedantic -Werror
+LDFLAGS =
+
+ALL_LDFLAGS = -pie -Wl,--fatal-warnings
+
+ALL_CFLAGS = -std=c99 -fPIE $(CFLAGS)
+ALL_LDFLAGS += $(LDFLAGS)
+
+C_OBJS = $(patsubst %.c,%.o,$(wildcard *.c))
+AS_OBJS = $(patsubst %.s,%.o,$(wildcard *.s))
+ALL_OBJS = $(filter-out example.o,$(C_OBJS) $(AS_OBJS) vendor/unity.o)
+
+CC_CMD = $(CC) $(ALL_CFLAGS) -c -o $@ $<
+
+all: tests
+	@./$<
+
+tests: $(ALL_OBJS)
+	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) -o $@ $(ALL_OBJS)
+
+%.o: %.s
+	@$(AS) -o $@ $<
+
+%.o: %.c
+	@$(CC_CMD)
+
+vendor/unity.o: vendor/unity.c vendor/unity.h vendor/unity_internals.h
+	@$(CC_CMD)
+
+clean:
+	@rm -f *.o vendor/*.o tests
+
+.PHONY: all clean

exercises/hello-world/README.md

@@ -0,0 +1,21 @@
+# Hello World
+
+The classical introductory exercise. Just say "Hello, World!".
+
+["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is
+the traditional first program for beginning programming in a new language
+or environment.
+
+The objectives are simple:
+
+- Write a function that returns the string "Hello, World!".
+- Run the test suite and make sure that it succeeds.
+- Submit your solution and check it at the website.
+
+If everything goes well, you will be ready to fetch your first real exercise.
+## Source
+
+This is an exercise to introduce users to using Exercism [http://en.wikipedia.org/wiki/%22Hello,_world!%22_program](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program)
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

exercises/hello-world/example.s

@@ -0,0 +1,9 @@
+.section .rodata
+msg: .string "Hello, World!"
+
+.text
+.global hello
+hello:
+    adrp x0, msg
+    add x0, x0, :lo12:msg
+    ret

exercises/hello-world/hello_world.s

@@ -0,0 +1,9 @@
+.section .rodata
+msg: .string ""
+
+.text
+.global hello
+hello:
+    adrp x0, msg
+    add x0, x0, :lo12:msg
+    ret

exercises/hello-world/hello_world_test.c

@@ -0,0 +1,21 @@
+// Version: 1.1.0
+
+#include "vendor/unity.h"
+
+extern const char *hello(void);
+
+void setUp(void) {
+}
+
+void tearDown(void) {
+}
+
+void test_say_hi(void) {
+    TEST_ASSERT_EQUAL_STRING("Hello, World!", hello());
+}
+
+int main(void) {
+    UNITY_BEGIN();
+    RUN_TEST(test_say_hi);
+    return UNITY_END();
+}